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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

A Comparison of Predefined and Dynamic Mapping for Open-Source AMRs

Tahamtani, Behrad, Kagerin, Christian January 2023 (has links)
With the trend toward more connected and automated industries, the benefits of an open-source version of standard solutions become clear. It is common place to use proprietary Automated Guided Vehicles (AGV); however, using open-source Autonomous Mobile Robot (AMR) solutions would allow smaller and medium-sized businesses to compete with larger businesses. Implementing an open-source solution would require adapting a mapping technique that it will use. The study compares using a predefined map and a dynamically run-time generated map and the difference in time from start to destination and the distance traveled. The results show that the dynamic and predefined perform better or worse depending on the environment. Using predefined mapping indicates an overall better solution for industries because while the distance and time are pretty close, the variance difference is too significant for an environment that requires consistency.
42

The Silenced Pandemic?: Reconstructing History and Spatiality of EU’s Biopolitics on Antimicrobial Resistance

Molinari, Nora, Miggelbrink, Judith 14 December 2023 (has links)
Until now, tracing the genealogical lines of EEC/EU Antibiotic Resistance policy has been a gap in social science research that has focused on the policies of individual countries. This Working Paper raises the question how Antimicrobial Resistance (AMR) has developed as an epistemic object in terms of biopolitical and spatial regulatory design of EEC/EU. It also asks what cultural ideas and imaginations have been associated with antibiotics since their introduction. To this end, a historical discourse analysis was conducted combining the perspectives of human geography and historical sociology. First cases of resistance occurred at short intervals with the introduction of new antibiotics in both human and veterinary medicine, and the discovery of the mechanism of horizontal gene transfer attracted global attention in the 1960s. Nevertheless, the belief in the need for an expansionary mode of production outweighed scientific doubt and the longer-term health of the population, so that regulatory interventions were more appearance than substance. Only in the wake of the geopolitical rise of the EU and BRICS countries and new ‘pandemic risks’, a general turn to security dispositif and neoliberal-individualist governmentality rearranged the coordinates of AMR policy to some extent. The interpretation of our present as a “multi-crisis”, which has become increasingly established in the “West” in the wake of climate crisis and Covid19, is apparently contributing to an increasing assessment of AMR as an unintended side-effect of an expansionary economy and lifestyle, with no regulatory responses to date that address systemic causes rather than suggesting a fiction of control.
43

Characterization of Prokaryotic Ku DNA Binding Properties

Koechlin, Lucas January 2020 (has links)
DNA damage occurs to all living things; its subsequent repair is a crucial component of life. The most dangerous, and potentially most useful form of DNA damage is the double strand break (DSB). A DSB is defined by breaks occurring to both sugar phosphate backbones in close enough proximity that they lead to the separation of the two pieces of the DNA. This type of damage will kill the cell if left unrepaired. It is the most lethal type of DNA damage. Most living organisms have also developed ways to take advantage of DSBs through their repair systems, primarily as a means of introducing genetic variation. There are two primary DSB repair pathways across life: homologous recombination (HR) and non-homologous end-joining (NHEJ). The focus of this work is NHEJ. NHEJ is known as “error-prone” because it does not use a homologous template and can introduce small addition or deletion mutations during the repair process. This pathway has been extensively studied in eukaryotes and is known as the primary form of DSB repair in mammalian cells, however the prokaryotic NHEJ system was more recently identified and as a result, a void of information surrounds it. NHEJ is comprised of 3 core steps: DSB recognition and binding, DNA end processing, and ligation. In the eukaryotic version of NHEJ these 3 steps involve a plethora of factors; conversely, in the prokaryotic version, the same functionality is accomplished by just 2 proteins, bacterial Ku and LigD. The focus of this research is Ku: the DNA end-binding protein responsible for identifying the DSB, binding and protecting the DNA end, as well as recruiting LigD to the break. Ku is composed of 2 domains, the first of which is predicted to be highly homologous to eukaryotic Ku’s equivalent domain; this is the core domain which forms a ring-like structure that DNA threads through. The second is completely unique to bacterial Ku, it is the C-terminal domain, which can further be split into 2 sub-domains, the minimal C-terminus, and the extended C-terminus. The sub-domains are defined by their level of conservation across bacterial species, with the minimal C-terminus being highly conserved, while the extended C-terminus is highly variable. Using DNA-binding assays and several mutant constructs which affect the C-terminal domain, I show that this C-terminus is unexpectedly responsible for destabilizing the Ku-DNA interaction. This observation leads me to hypothesize that maintaining a weak interaction with DNA is important for Ku because of the other proteins which need access to the DNA (e.g. replicative helicase). While Ku is bound, it could be capable of blocking regions of DNA, in turn blocking other vital cellular processes like replication. Ku maintaining a lower affinity for DNA should facilitate Ku displacement by other proteins. A tighter binding would restrict Ku’s freedom to move on DNA making it more likely to inhibit other critical pathways. To better understand Ku, I attempted to solve the Ku structure using X-ray crystallography, and was able to achieve crystals of Ku, however diffraction was too limited for a structure. Another way to investigate the validity of my proposed model is to use a biophysical approach with atomic force microscopy (AFM) to visualize protein-DNA complexes. The initial work has established key controls for future Ku-DNA AFM work by imaging and analyzing Ku on its own. Interest in bacterial NHEJ is two-fold from the antimicrobial perspective: NHEJ is a highly mutagenic pathway, so it serves as a proverbial well for differentiation and thus the development of antimicrobial resistance (AMR); NHEJ is very important in bacteria that enter a stationary phase due to their lack of a homologous piece of DNA for HR. Thus, NHEJ inhibition could be useful for slowing bacterial evolution and potentially as a treatment for infections such a Mycobacterium tuberculosis, which is known to lie dormant in host macrophages for long periods of time. To investigate the viability of NHEJ inhibition, I had begun the process of creating ∆ku strains of Pseudomonas aeruginosa to simulate Ku inhibition under various conditions. This Ku project is the focus of the first two chapters, however, during my Master’s degree I participated in 2 other major projects. The third chapter details a bacterial DNA damage tolerance pathway, which similarly is highly mutagenic and poorly characterized: the ImuABC translesion synthesis polymerase complex. The fourth and final chapter details the work for a Journal of Visualized Experiments article meant to highlight the benefits of AFM as a means of studying protein-DNA interactions. / Thesis / Master of Science (MSc)
44

Label-Free Electrochemical Sensor for Rapid Bacterial Pathogen Detection Using Vancomycin-Modified Highly Branched Polymers

Schulze, H., Wilson, H., Cara, I., Carter, Steven, Dyson, Edward, Elangovan, R., Rimmer, Stephen, Bachmann, T.T. 12 May 2021 (has links)
Yes / Rapid point of care tests for bacterial infection diagnosis are of great importance to reduce the misuse of antibiotics and burden of antimicrobial resistance. Here, we have successfully combined a new class of non-biological binder molecules with electrochemical impedance spectroscopy (EIS)-based sensor detection for direct, label-free detection of Gram-positive bacteria making use of the specific coil-to-globule conformation change of the vancomycin-modified highly branched polymers immobilized on the surface of gold screen-printed electrodes upon binding to Gram-positive bacteria. Staphylococcus carnosus was detected after just 20 min incubation of the sample solution with the polymer-functionalized electrodes. The polymer conformation change was quantified with two simple 1 min EIS tests before and after incubation with the sample. Tests revealed a concentration dependent signal change within an OD600 range of Staphylococcus carnosus from 0.002 to 0.1 and a clear discrimination between Gram-positive Staphylococcus carnosus and Gram-negative Escherichia coli bacteria. This exhibits a clear advancement in terms of simplified test complexity compared to existing bacteria detection tests. In addition, the polymer-functionalized electrodes showed good storage and operational stability.
45

Pengar, piller och policy : En marknadsanalys av den svenska och italienska antibiotikamarknaden och effekterna på antimikrobiell resistens / Pennies, pills and policy : A market analysis of the Swedish and Italian antibiotic market and the effects on antimicrobial resistance

Jonsson, Julia, Åkerman, Ylva January 2024 (has links)
Över - eller felanvänd antibiotika leder till ökad risk för antimikrobiell resistens. När en bakterie har blivit resistent så har det skapats en motståndskraft, vilket gör antibiotikan verkningslös. Antibiotika är ett livsnödvändigt läkemedel, då det används rutinmässigt vid kirurgiska ingrepp och för att bekämpa bakteriella infektioner. Det finns inget alternativt läkemedel, vilket innebär att om antibiotika blir verkningslös är de globala konsekvenserna katastrofala. Den negativa utvecklingen har resulterat i att EU - kommissionen klassificerar antimikrobiell resistens (AMR) som ett av de tre största hälsohoten i världen. Internationella organisationer har presenterat krav och rekommendationer för hur länder ska hantera antibiotika och dess resistens, vilket har implementerats olika väl. Sverige har en av de lägsta frekvenserna av resistenta bakterier inom EU, medan Italien har en av de högsta. Hypotesen är att de nämnda ländernas resistensgrad har ett samband med hur väl man implementerat strukturer, regleringar och strategier på antibiotikamarknaden. Hypotesen undersöks genom en marknadsanalys baserat på en anpassad SCP - modell där Sveriges och Italiens respektive utfall värderas.  I utfallen framgår det att Sveriges antibiotikamarknad är mer kontrollerad än den italienska. En mer styrd marknad skapar möjligheten att kontrollera antibiotikakonsumtionen, vilket i sin tur bestämmer resistensgraden. Å andra sidan innebär en mer kontrollerad marknad att läkemedelsföretagens vinstgaranti försvinner, dessa kan tvingas lämna marknaden vilket leder till brist på antibiotika. En mindre styrd marknad gynnar däremot läkemedelsföretagen då det finns en vinstgaranti och en större konsumtion. Nackdelen är att resistensgraden ökar. I marknadsanalysen presenterades även att länderna skiljer sig i ansvarsfördelning, då hälso - och sjukvård är mer decentraliserad i Italien jämfört med Sverige. Strukturer, regleringar och strategier för att hantera AMR implementerades nationellt i Sverige, medan det i Italien är upp till varje region att agera. Italiens ansvarsfördelning resulterar i att resistensgraden skiljer mellan det södra och norra regionerna, då regionernas styren skiljer i kvalitet.  Slutligen lämnas förslag på förändringar för respektive land. Sverige behöver erbjuda en vinstgaranti för läkemedelsföretagen för att kunna säkerställa tillgången till antibiotika. Det råder brist idag, vilket medför att marknaden behöver bli mer attraktiv för företagen. Italien behöver förändra ansvarsfördelningen och införa nationella strukturer, regleringar och strategier. Det kommer öka möjligheten för mer påkostade åtgärder som gäller för alla regioner, vilket hanterar AMR mer effektivt. / An excessive or incorrect use of antibiotics can result in an increased prevalence of antimicrobial resistance. When a bacterium has become resistant, resilience against antibiotics is created, which makes the drug ineffective. Antibiotics are vital drugs, as they are routinely used in surgical procedures and combat bacterial infections. Often, there is no alternative medicine, which means that when an antibiotic becomes ineffective, the consequences are catastrophic for the global population. The global increase in resistance has forced the European Commission to classify antimicrobial resistance (AMR) as the world's third largest public health threat. International organizations have presented requirements and recommendations for how countries should handle antibiotics and their resistance. However, it has been the nation’s responsibility to implement these changes. Sweden has one of the lowest prevalence of antibiotic resistant bacteria in the EU, while Italy has one of the highest. The essay hypothesizes that the mentioned countries' degree of resistance can be explained by how well structures, regulations, and strategies are implemented. The hypothesis is evaluated through a market analysis where a reconstructed SCP - model is applied where Sweden’s and Italy’s respective performance is presented. The essay found that the Swedish antibiotic market is more regulated than the Italian. A more regulated market creates the opportunity to control antibiotic consumption, which further controls the degree of resistance. On the other hand, an over - regulated market means that there is no guarantee of profit for the pharmaceutical companies which often forces the companies to leave the market. A less regulated market benefits pharmaceutical companies as there is a guarantee of profit and larger consumption. The disadvantage is that the degree of resistance increases. In the market analysis, it is also presented that the countries differ in the distribution of responsibilities, as healthcare is more decentralized in Italy compared to Sweden. The structures, regulations, and strategies to manage AMR were implemented nationally in Sweden, while in Italy it is up to each region to act. Italy's division of responsibility results in that the degree of resistance differs between the southern and northern regions, as the regions' governments differ in quality. Finally, the essay presents proposals for changes for each country. Sweden should offer a profit guarantee for pharmaceutical companies, as they need access to a broad selection of antibiotics. The existing shortage should be dealt with, which is why the market needs to be more attractive for companies. Italy needs to change the distribution of responsibilities and introduce national structures, regulations, and strategies. This will increase the possibility of more costly measures that apply to all regions, which will manage AMR more effectively.
46

Modeling an AMR corpus using a Graph Extension Grammar

Arvidsson Örnberg, Alexander January 2024 (has links)
Abstract Meaning Representation (AMR) is a type of semantic graph, which is a convenient and popular way of representing natural language. Linguistic concepts are modeled as nodes with edges between them describing their relationships. A Graph Extension Grammar (GEG) is a type of graph grammar that can generate semantic graphs akin to AMR. The aim of this thesis is to explore the limitations and suitability of using graph extension grammarsfor semantic generation. This is done by modeling a single GEG after an AMR corpus.A large portion of this thesis is focused on generic structures in AMRs, and how tomodel them in a GEG. Further improvements to the formalism are also presented. The conclusion states that the GEG formalism is suitable for semantic graph generation and that it is possible to generate a corpus using a single GEG. However, large corpora may be difficult and time-consuming to model due to complex reentrancies.
47

Propagation d'une onde de choc en présence d'une barrière de protection / Propagation of blast wave in presence of the protection barrier

Eveillard, Sébastien 12 September 2013 (has links)
Les travaux de thèse présentés dans ce mémoire s’inscrivent dans le cadre du projet ANR BARPPRO. Ce programme de recherche vise à étudier l’influence d’une barrière de protection face à une explosion en régime de détonation. L’objectif est d’établir des méthodes de calcul rapides de classement des zones d’effets pour aider les industriels au dimensionnement des barrières de protection. L’une à partir d’abaques, valable pour des configurations en géométrie 2D, sur des plages spécifiées de paramètres importants retenus, avec une précision de +/- 5%. L’autre à partir d’une méthode d’estimation rapide basée notamment sur les chemins déployés, valable en géométrie 2D et en géométrie 3D, mais dont la précision estimée est de +/- 30%. Afin d’y parvenir, l’étude s’appuie sur trois volets : expérimental, simulation numérique et analytique. La partie expérimentale étudie plusieurs géométries de barrière de protection à petites échelles pour la détonation d’une charge gazeuse (propane-oxygène à la stoechiométrie). Les configurations expérimentées servent à la validation de l’outil de simulation numérique constitué du solveur HERA et de la plateforme de calcul TERA 100. Des abaques d’aide au dimensionnement ont pu être réalisés à partir de résultats fournis par l’outil de simulation (3125 configurations de barrière de protection, TNT). L’étude des différents phénomènes physiques présents a également permis de mettre en place une méthode d’estimation rapide basée sur des relations géométriques, analytiques et empiriques. L’analyse de ces résultats a permis d’établir quelques recommandations dans le dimensionnement d’une barrière de protection. Les abaques et le programme d’estimation rapide permettent à un ingénieur de dimensionner rapidement une barrière de protection en fonction de la configuration du terrain et de la position de la zone à protéger en aval du merlon. / This thesis is a part of the ANR BARPPRO project. This research program studies this influence of the protection barrier during an explosion detonation. The goal of this project is to establish fast-computation methods of area classification effects to help the industrial to design the protection barrier on the SEVESO sites. One from abacus, for configurations in 2D geometry on specified parameters used, with an accuracy of +/- 5%. The other from a fast-running method based on broken lines for configurations in 2D and 3D geometries, but the accuracy is +/- 30%. This study includes three approaches: experimental, numerical simulation and analytical approaches. The experimental part studies several geometries of the protection barrier for a gaseous explosion (stoichiometric propane-oxygen mixture) at small scales. The experimental configurations used to validate the numerical simulation tool constituted of the HERA software and the TERA 100 supercomputer. The overpressure charts were able to generate from the numerical results (3125 configurations of the barrier for a TNT charge). The analysis of these results allows to establish different recommendations in the design of the protection barrier. The study of the different physical phenomena present has also helped to set up a fast-running method based on the geometrical, empirical and analytical relations. All these tools will enable an engineer to analyze and estimate the evolution of overpressure around the barrier as a function of the site’s dimensions.
48

Epidemiologic Approaches to Understanding Gonorrhea Transmission Dynamics and the Development of Antimicrobial Resistance

2016 February 1900 (has links)
Globally, the incidence of infection caused by Neisseria gonorrhoeae is the second highest among the bacterial sexually transmitted infections. In Canada, declining rates during the 1990s suggested progress toward curbing gonorrhea; however, those have been increasing since 1999, with rates in Saskatchewan among the highest in the country. Infection can cause serious complications in men and women, and reported resistance to third-generation cephalosporins could lead to potentially untreatable infections. Increased understanding of gonorrhea transmission dynamics, sexual networks, and predictors of antimicrobial resistance development is needed to inform the development of improved approaches to prevention and treatment. The research presented herein draws upon data from Shanghai, China, and Saskatchewan, Canada, to compare and contrast varying epidemiologic approaches to enhancing understanding of gonorrhea in the two settings. Using traditional statistical approaches, multi-level statistical modeling, social network analysis, and dynamic simulation modeling, questions related to sexual behavior, partner presentation, and antimicrobial resistance development are explored. Each technique is evaluated for its potential contribution to overall understanding of the issues related to the ongoing gonorrhea epidemic, globally, and in Saskatchewan. The relative strengths and limitations of the application of the analytical approaches in the different settings are described. Socio-demographic characteristics provided useful indicators of antimicrobial resistant infection among patients with gonorrhea from Shanghai. Further, socio-demographic characteristics were also useful for predicting presentation of a partner for testing and treatment and the use of condoms during intercourse, among this study population. In Saskatchewan, socio-demographic characteristics were useful in predicting coinfection with gonorrhea and chlamydia at the time of diagnosis as well as repeat infection with gonorrhea. Social network analysis of the Saskatchewan dataset provided little additional understanding of the gonorrhea epidemic in the province. This result was largely related to how STI data are collected and stored in the province. The utility of dynamic simulation modeling to investigate the potential impact of antimicrobial resistance in Saskatchewan was also limited due to the same data constraints. However, the insight gained from the model building process and findings from the working model did offer a starting point for conversations around the best ways to postpone the development of antimicrobial resistance in N. gonorrhoeae in Saskatchewan, as well as contribute additional information about how the ways in which STI data are collected and stored in the province considerably restrict the applicability of otherwise powerful epidemiologic tools. With persistently high rates of disease transmission, and the threat of untreatable infections due to antimicrobial resistance, N. gonorrhoeae remains a substantial public health threat locally and globally. The research presented herein describes various approaches to understanding and controlling this disease, applied in contrasting settings. There are a wide variety of elements that should be considered when choosing the appropriate tool(s) to address gonorrhea in a given population; there is no “one size fits all” solution. The local epidemiology of disease, cultural and behavioural norms, the characteristics of the notifiable disease reporting and information systems, and the availability of suitable data all affect the relative strengths and weaknesses of the available analytic methods and disease control approaches.
49

Encodage entropique des indices binaires d'un quantificateur algébrique encastré

Lakhdhar, Khaled January 2009 (has links)
Ce mémoire propose un algorithme de compression sans perte des indices binaires d'un quantificateur algébrique encastré utilisé par le codec AMR-WB+ pour encoder certaines des trames d'un signal audio. Une étude détaillée des statistiques a été menée dans le but de développer un algorithme efficace de compression et réduire par conséquent la longueur moyenne du code binaire utilisé par le codec AMR-WB+. En se basant sur cette étude des statistiques, deux techniques ont été combinées : l'encodage par plage et l'encodage par contexte qui se sont montrés très efficaces pour estimer les probabilités des différents indices. En utilisant l'encodage arithmétique en version entière pour générer le code binaire, l'algorithme proposé permet de réduire sans perte jusqu'à 10% de la longueur du code utilisé par le AMR-WB+ tout en respectant la contrainte d'une application temps réel destinée à des terminaux GSM.
50

Propagation d'un choc dans un milieu hétérogène

Elbaz, Déborah 03 November 2011 (has links) (PDF)
Dans le cadre de la fusion par confinement inertiel en attaque directe, l'utilisation de mousses en tant qu'ablateur permet de réduire les instabilités hydrodynamiques créées sur la cible par l'irradiation directe des faisceaux laser. Des études antérieures ont été réalisées en considérant cette mousse comme homogène. Or, étant composée de fibres de CH baignant dans du DT, elle présente un aspect hétérogène. Le but de cette thèse est d'étudier l'effet de cette hétérogénéité sur la vitesse du choc lors de l'irradiation laser de la cible. Une étude expérimentale sur tube à choc et des études numériques avec le code HERA nous ont permis de trouver que le choc se propage plus rapidement dans le milieu hétérogène que dans le milieu homogène de densité moyenne équivalente. Cette écart de vitesse dépend du taux de présence des fibres de CH, du rapport de densité entre les deux matériaux constituant la mousse, de leur coefficient adiabatique et de la géométrie de la mousse. Nous avons modélisé la mousse de diverses manières, en partant du plus simple au plus compliqué, afin de se rapprocher d'une configuration réaliste. La modification de la vitesse du choc étant dûe à la baroclinicité qui, lors de l'interaction du choc avec l'interface entre le CH et le DT, crée un dépôt de vorticité, responsable de l'accélération du choc. Par conséquent, une interface plane et perpendiculaire au front de choc maximise ce dépôt de vorticité et augmente les écarts de vitesse entre milieux hétérogènes et homogènes. Une corrélation entre l'énergie cinétique derrière le choc et la différence relative des vitesses de choc a été trouvée. Nous avons comparé nos résultats à deux modèles analytiques, mais le système n'étant pas fermé, nous ne pouvons pas, pour le moment, élaborer de modèle prédictif.

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