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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.
11

A Study Of Organizational Rightsizing : Actors, Processes And Outcome

Nirmala, Maria Christine 01 1900 (has links)
The pressure for economic integration has been reinforced by developments in technology, changes in market structures and the emergence of transnational corporations. Rightsizing has emerged as a critical process in this present era of shrinking space, shrinking time and disappearing borders in the context of employee engagement and human capital. It is often adopted by most organizations to help them become more agile and flexible and thereby cater to the competitive demands. The diverse impacts of rightsizing on various actors however question the justice aspect of the entire process. This study addresses rightsizing from the perspective of social justice by taking into consideration the assessments of the processes by the affected actors namely, the implementers who drive the rightsizing processes; the separated who leave the organization as a result of rightsizing; and the stayers who remain in the organization and have observed the process. It also aims at understanding the various rightsizing processes from an empirical perspective and examines the causal relatedness of the rightsizing processes and outcome across some of the Indian organizations and the actors. Review of literature: The gamut of literature in rightsizing has provided a strong foundation for the researcher to gain a critical understanding of the various processes underlying rightsizing. The key challenge in rightsizing concerns the fairness aspect of the entire process considering the fact that in most cases rightsizing results in gains for some people and loss for others. Given that judgments of fairness are highly subjective, the lack of an absolute standard for determining fairness in this situation has been identified as a gap. As many studies highlight the ambivalence in results with regard to the outcome of rightsizing and attribute them to the rightsizing processes, the relationship of the rightsizing processes and the outcome has emerged as an area of interest. Though there have been correlation based analysis between various rightsizing variables, causal models that link the rightsizing processes to the outcome have been found missing. The dearth of studies from the Indian set up have also prompted the need to build segregate and aggregate causal models of rightsizing processes and outcome at the organization and actor levels. Aim, objectives and methodology: The aim of this study has been to identify the rightsizing processes that contribute towards positive outcome for both the organization and the individuals concerned from the social justice perspective. The objectives were: 1. To compare and contrast the implementation of rightsizing processes in some of the Indian organizations. 2. To develop a framework for understanding and classifying rightsizing processes in relation to the social justice perspective. 3. To identify the effective rightsizing processes that contribute significantly towards minimizing individual stress and maximizing commitment towards the organization. 4. To outline appropriate guidelines based on the justice perspectives of the actors for better implementation of rightsizing in organizations. The conceptual model links the actors, their assessments of the rightsizing processes and the outcome of the entire process as affecting their individual stress and commitment towards the organization. The just processes of rightsizing have been decided based on the assessment of actors and on the extent of their agreement with one another on implementation of the discrete rightsizing practices. Accordingly those practices that all the three groups of actors, namely the implementers, stayers and separated perceive to have been implemented will be classified as the "best practices" or system 4 practices; the practices that have been perceived to have been implemented by the implementers and stayers but not the separated will be classified as the "better practices" or system 3 practices; those practices that the implementers and separated perceive as implemented will be the "ineffective practices" or system 2 practices; and the practices where all the three groups differ with one another with regard to the extent of implementation will be termed the "poor practices" or system 1 practices. The questionnaire was finalized after a preliminary and pilot study. Data was collected from 727 respondents across four organizations, one private manufacturing unit referred to as Org-1, one state public sector unit referred to as Org-2, two central public sector units referred to as Org-3 and Org-4. The total sample consisted of 137 implementers, 320 stayers and 270 separated. Results and discussion: The first part of the analysis focused on validating the rightsizing processes through factor analysis and also testing the reliability using Chronbach alpha. The implementation of the rightsizing processes across the four organizations was compared using Bonferroni post hoc comparisons. Org-1 and Org-4 had implemented most of the rightsizing practices adequately. The perceptions of the employees of Org-2 and Org-3 were found to be significantly inadequate when compared to Org-1 and Org-4 with respect to many of the practices. The second set of analysis compares the assessments of the actors with regard to the implementation of the various rightsizing practices, and classifies them into one of the four systems based on the framework developed. The system 4 practices consist of, the notification period; the severance package; the amount of money that the organizations wished to save after rightsizing and avoidance of ineffective cost reduction strategies. The outcome of rightsizing with respect to role clarity and role sufficiency also falls into system 4. The system 3 practices consist of understanding the need for rightsizing; the need for manpower reduction, proactive cost reduction strategies, separation of the sick and criteria for separation of the redundant. System 1 practices comprise of internal stakeholders, alternate strategies adopted by the organization before resorting to separation of the employees, preparation and communication, leadership, review and control and assistance provided to the separated. The outcome with regard to job security and commitment also falls in this category. The final set of analysis aims at identifying those processes that contribute significantly towards the outcome at both the organizational level and from the perceptions of the actors through path analysis. The path analysis was conducted at the segregate and aggregate levels for the organizations and the actors. Initially a full segregate model where all the independent variables are linked to the dependent variables was fit for the 4 organizations and for the 3 categories of actors. Those processes that contributed significantly towards the outcome with respect to the actors and the organizations were structured onto two final aggregate models. The validity of these aggregate models was examined for the organizations and actors respectively. Conclusion: This study provides a deeper understanding of the various processes underlying rightsizing in the three different stages of implementation. These validated measures can be used as a template by the organizations to study and guide further rightsizing initiatives. Through this research three groups of individuals diversely affected by rightsizing have been brought together under one common framework which is a methodological innovation. Inspite of having different interests, it is possible to obtain a consensus in their assessments of some of the rightsizing practices. This is an important conclusion that can be drawn in support of the social justice perspective with regard to rightsizing. The relationship between the rightsizing processes as affecting the outcome of stress and commitment can also be understood from a causal perspective across organizations and actors through segregate and aggregate models. The best practices with knowledge capital and social capital can also be included in understanding the perspectives of the actors and classification of rightsizing best practices in future work.
12

Rörelsehastighetens påverkan på Virtual Reality Sickness i en mobilapplikation som simulerar en berg- och dalbana / Motion Rate Impact on Virtual Reality Sickness in a Mobile Application Simulating a Roller Coaster

Frösslund, Lukas, Karlsson, Johannes January 2018 (has links)
As Virtual Reality grows larger as a commercial product for private use, Virtual Reality Sickness emerges as an increasingly common issue. The knowledge about this type of motion sickness has been around for a long time, and there is no shortage of research on the subject, but in many cases it is based on technology that is fundamentally different from today's. This study aimed at investigating the impact of velocity on Virtual Reality Sickness through tests performed in a simulation of a rollercoaster optimized for use with Samsung Gear VR. A quantitative survey was performed where 21 participants tested the simulation at three different velocities on three separate days in which the level of motion sickness was estimated using standardized forms during all test periods. The results indicate a difference between the different velocities ability to induce Virtual Reality Sickness, however, the evidence was not sufficient to prove that this was not due to chance. Analysis, on the other hand, indicates that there is a positive correlation between Virtual Reality Sickness and presence, the feeling of being in a certain environment, though physically being elsewhere. / I takt med att Virtual Reality växer sig större som en kommersiell produkt för privat bruk så träder Virtual Reality Sickness fram som ett allt mer utbrett problem. Vetskapen om denna typ av åksjuka har funnits länge och det råder ingen brist på forskning i ämnet, men i många fall är den byggd på teknik som är fundamentalt annorlunda än dagens. Denna studie ämnade att undersöka rörelsehastighetens påverkan på Virtual Reality Sickness genom tester utförda i en simulering av en berg- och dalbana optimerad för användning med Samsung Gear VR. En kvantitativ undersökning utfördes där 21 deltagare fick testa simuleringen i tre olika hastigheter under tre separata dagar i vilken nivån av åksjuka uppskattades med hjälp av standardiserade formulär under samtliga testtillfällen. Resultaten tyder på en skillnad mellan de olika hastigheternas förmåga att framkalla Virtual Reality Sickness, dock var inte underlagen tillräckliga för att bevisa att detta inte berodde på slumpen. Analys tyder däremot på att det finns en positiv korrelation mellan Virtual Reality Sickness och presence, känslan av att befinna sig i en viss miljö fast att man fysiskt är någon annanstans.
13

Análisis del sistema de navegación por satélite europeo EGNOS para su integración con VRS

Olivares Belinchon, Jesús Lorenzo 21 March 2016 (has links)
[EN] Abstract Global Navigation Satellite Systems (GNSS) have transformed the positioning and navigation techniques, becoming the indispensable today for multiple applications. Satellite navigation is one of the new forms of navigation and has multiple advantages over existing techniques. It can provide information to users in any location, without direct vision and comprehensively worldwide. Therefore, we are witnessing the arrival of a navigation system that, by itself, could give boaters the ability to perform positioning and route planning without the need to resort to another method or additional information. The International Civil Aviation Organization (ICAO) began in early 1990 a series of activities to define "air navigation system of the future", whose base would be the GNSS systems. The potential applicability of these systems is a reality, fulfilling the requirements of many operations navigation: accuracy, integrity, availability and continuity. One example that is already being used for CAT III operations, such as aircraft landing. The signal emitted by satellites undergoes a series of errors in its spread and the operating system to be limited for many applications. Therefore, the real-time positioning requires the use of a differential corrections to improve the performance of GNSS systems. Current differential correction systems can be grouped in local systems or LADGPS (Local Area DGPS), and extensive systems or WADGPS area (Wide Area DGPS). In March 2011 the European Commission declared the 'Safety-of-Life' service of EGNOS suitable for use in civil aviation, which is the WADGPS system used in this research together with the System of Permanent Reference Stations VRS, as system LADGPS. The objective of this thesis is the analysis of the possible integration of EGNOS navigation system with positioning methodology from ground Reference Stations Trimble VRS. It aims to improve the positioning accuracy of the EGNOS system implementing a priori more accurate VRS solution. In short, we seek a proposed methodology of positioning that has the best of both, we call EGNOS / VRS. Having defined the methodology to be used for determining the positioning EGNOS / VRS new performances are analyzed and improved accuracy is verified, allowing use is new methodology for applications with requirements for positioning accuracy, such as in agriculture precision. / [ES] Resumen Los Sistemas Globales de Navegación por Satélite (GNSS) han transformado las técnicas de posicionamiento y navegación, llegando a ser en la actualidad indispensable para múltiples aplicaciones. La navegación por satélite es una de las nuevas formas de navegación y tiene múltiples ventajas sobre las técnicas existentes. Puede proporcionar información a los usuarios en cualquier ubicación, sin necesidad de visión directa y de forma global en todo el planeta. Por tanto, estamos asistiendo a la llegada de un sistema de navegación que, por sí mismo, podría proporcionar a los navegantes la capacidad de realizar el posicionamiento y la planificación de rutas sin la necesidad de recurrir a otro método o información adicionales. La Organización de Aviación Civil Internacional (OACI) inició a principios de 1990 una serie de actividades encaminadas a definir el "sistema de navegación aérea del futuro", cuya base serían los sistemas GNSS. La aplicabilidad potencial de estos sistemas es ya una realidad, cumpliendo los requerimientos de muchas operaciones de navegación: precisión, integridad, disponibilidad y continuidad. Sirva como ejemplo que se está utilizando ya para operaciones de CAT III, como el aterrizaje de aeronaves. La señal que emiten los satélites sufre una serie de errores en su propagación y funcionamiento del sistema que los limitan para muchas aplicaciones. Por ello, el posicionamiento en tiempo real necesita de la utilización de unas correcciones diferenciales que mejoran el rendimiento de los sistemas GNSS. Los sistemas actuales de corrección diferencial los podemos agrupar en sistemas locales o LADGPS (Local Area DGPS), y sistemas de área extensa o WADGPS (Wide Area DGPS). En marzo de 2011 la Comisión Europea declaró el servicio 'Safety-of-Life' de EGNOS apto para su uso en aviación civil, siendo éste el sistema WADGPS utilizado en esta investigación junto con el sistema de Estaciones de Referencia Permanentes por VRS, como sistema LADGPS. El Objetivo de ésta Tesis es el análisis de la posible integración del sistema de navegación EGNOS con la metodología de posicionamiento a partir de Estaciones de Referencia en tierra VRS de Trimble. Se pretende mejorar la precisión de posicionamiento del sistema EGNOS implementando la solución VRS, a priori más precisa. En definitiva, buscamos una propuesta de metodología de posicionamiento que tenga lo mejor de ambas, que llamaremos EGNOS/VRS. Una vez definida la metodología a emplear para la determinación del posicionamiento EGNOS/VRS se analizan los nuevos rendimientos y se verifica la mejora de precisión, lo que permite utilizar está nueva metodología para aplicaciones con más requisitos en exactitud de posicionamiento, como por ejemplo en agricultura de precisión. / [CA] Resum Els Sistemes Globals de Navegació per Satèl¿lit (GNSS) han transformat les tècniques de posicionament i navegació, arribant a ser en l'actualitat indispensable per a múltiples aplicacions. La navegació per satèl¿lit és una de les noves formes de navegació i té múltiples avantatges sobre les tècniques existents. Pot proporcionar informació als usuaris en qualsevol ubicació, sense necessitat de visió directa i de forma global en tot el planeta. Per tant, estem assistint a l'arribada d'un sistema de navegació que, per si mateix, podria proporcionar als navegants la capacitat de realitzar el posicionament i la planificació de rutes sense la necessitat de recórrer a un altre mètode o informació addicionals. L'Organització d'Aviació Civil Internacional (OACI) va iniciar a principis de 1990 una sèrie d'activitats encaminades a definir el "sistema de navegació aèria del futur", la base del qual serien els sistemes GNSS. L'aplicabilitat potencial d'estos sistemes és ja una realitat, complint els requeriments de moltes operacions de navegació: precisió, integritat, disponibilitat i continuïtat. Servisca com a exemple que s'està utilitzant ja per a operacions de CAT III, com l'aterratge d'aeronaus. El senyal que emeten els satèl¿lits patix una sèrie d'errors en la seua propagació i funcionament del sistema que els limiten per a moltes aplicacions. Per això, el posicionament en temps real necessita de la utilització d'unes correccions diferencials que milloren el rendiment dels sistemes GNSS. Els sistemes actuals de correcció diferencial els podem agrupar en sistemes locals o LADGPS (Local Àrea DGPS) , i sistemes d'àrea extensa o WADGPS (Wide Àrea DGPS) . Al març de 2011 la Comissió Europea va declarar el servici 'Safety-of-Life' d'EGNOS apte per al seu ús en aviació civil, sent este el sistema WADGPS utilitzat en esta investigació junt amb el sistema d'Estacions de Referència Permanents per VRS, com a sistema LADGPS. L'Objectiu d'esta Tesi és l'anàlisi de la possible integració del sistema de navegació EGNOS amb la metodologia de posicionament a partir d'Estacions de Referència en terra VRS de Trimble. Es pretén millorar la precisió de posicionament del sistema EGNOS implementant la solució VRS, a priori més precisa. En definitiva, busquem una proposta de metodologia de posicionament que tinga el millor d'ambdós, que cridarem EGNOS/VRS. Una vegada definida la metodologia a emprar per a la determinació del posicionament EGNOS/VRS s'analitzen els nous rendiments i es verifica la millora de precisió, la qual cosa permet utilitzar està nova metodologia per a aplicacions amb més requisits en exactitud de posicionament, com per exemple en agricultura de precisió. / Olivares Belinchon, JL. (2016). Análisis del sistema de navegación por satélite europeo EGNOS para su integración con VRS [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/61981
14

Assessing risk for inpatient violence on high-security forensic psychiatric units

2015 August 1900 (has links)
While forensic psychiatric inpatient violence is a serious problem, research on risk assessment for this outcome is limited; the current research investigated the predictive validity of a number of structured risk/forensic instruments for inpatient violence. Research objectives included: 1) observing the profile of dynamic changes in violence risk detected by existing violence risk assessment instruments; 2) assessing whether existing violence risk assessment instruments could be used to assess risk for inpatient violence; 3) evaluating the contribution of dynamic risk measures to the prediction of inpatient violence; and 4) assessing the relationship between dynamic changes in risk and inpatient violence. Instruments included: the Historical Clinical Risk Management 20 - Version 3 (HCR-20V3), the Psychopathy Checklist Revised (PCL-R), the Short-Term Assessment of Risk and Treatability (START), the Revised Violence Risk Appraisal Guide (VRAG-R), and the Violence Risk Scale (VRS). Two studies were conducted on a maximum-security forensic psychiatric unit at Alberta Hospital Edmonton. Study 1 was a pseudo-prospective archival investigation (n = 99), while Study 2 was a prospective investigation (n = 19); all risk assessment scores were based on information available in institutional files. Instruments designed to capture dynamic/clinical risk variables (HCR-20V3, START, VRS) detected dynamic changes in risk in this setting over longer follow-ups (i.e., between admission and discharge), but not over shorter follow-ups (i.e., 28 day periods). Predictive validity analyses indicated that specialized measures designed to capture relevant dynamic/clinical variables were significant predictors of inpatient violence; instruments that were not designed for this purpose (PCL-R and VRAG-R), did not demonstrate predictive validity for inpatient violence. Dynamic measures consistently demonstrated incremental predictive validity for inpatient violence, beyond the static measures. Additionally, change scores demonstrated incremental relationships with decreased inpatient violence, beyond pretreatment scores. Put another way, positive risk change was associated with decreased violence over the course of the patients’ stays in hospital. Reliable and valid risk assessments are a necessary component of effective offender programming (Risk-Need-Responsivity Model) and the current results indicated that valid violence risk assessments for forensic psychiatric inpatient violence are possible. Implications for clinical practice and the reduction/mitigation of inpatient violence are discussed.
15

Étude in vitro et in vivo des interactions hôte/pathogènes dans un modèle de co-infection VRS/S pneumoniae / Host-pathogens interactions during RSV / S. pneumoniae infection immune response and p53 pathway

Bandeira Brancante Machado, Daniela 12 December 2017 (has links)
Les infections aiguës des voies respiratoires inférieures constituent la troisième cause de décès dans la population mondiale, avec 3,2 millions de décès. Parmi cette mortalité, au tour de 1 million c’était des enfants de moins de 5 ans, représentant la première cause de mortalité dans ce groupe d’âge, selon l'OMS en 2015. Le virus respiratoire syncytial (VRS) est considéré comme un agent étiologique important dans le millieux pediatric et les estimations sont que ce virus cause 3 million d’hospitalization par an. Un aspect important du pronostic des infections virales est le rôle de co-infection bactérienne. La combinaison d’agents viraux et bactériens a été signalée entre le VRS et les bactéries Streptococcus pneumoniae. En raison de l’importance clinique de cette co-infection et le taux élevé de circulation du VRS, il est important de comprendre comment le système immunitaire est affecté à l'infection de ces deux agents pathogènes. Notre étude identifie la réponse immunitaire dans les macrophages, ainsi comme les interactions entre le VRS et le facteur de transcription p53. Les résultats montrent un profil particulier a cette co-infection mixte dans le macrophages et des modifications dans la réponse immune innée que nous a permis de mieux comprendre les mécanismes de pathogenèse du VRS dans les cellules épithélial pulmonaires en regardant la régulation de p53. Dans la dernière partie, nous avons évalué l'impact direct de l’infection mixte chez les primates non-humain et ce modèle nous a montré les difficultés et complexités des établir une pneumonie sévère. / Respiratory viruses play a leading role in the etiology of respiratory infections. Currently, respiratory syncytial virus (RSV) is generally considered to be the etiologic agent of respiratory disease in pediatric importance, as children can develop bronchiolitis and pneumonia when infected with the virus. The first RSV infection occurs in the first two years of life in about 95% of children, with the peak incidence occurring in the first few months of life. An important aspect of the prognosis of viral infections is the role of bacterial co-infection. The combination of viral and bacterial agents has been reported between RSV and Streptococcus pneumoniae bacteria. Because of the clinical importance of this co-infection and the high rate of RSV circulation, it is important to understand how the immune system is affected by the infection of both pathogens. Our study was designed to evaluate the immune response in macrophages, in addition to interactions between RSV and p53 transcription factor. The results show a particular profile of this mixed co-infection in macrophages and p53 regulation that implies several modifications in the innate immune response and that allowed us to better understand the mechanisms of pathogenesis of RSV in pulmonary epithelial cells. In the last part, we evaluated the direct impact of mixed co-infection in non-human primates and this model showed us the difficulties and complexities of establishing severe pneumonia.
16

Caractérisation et modulation de la réponse immunitaire innée au cours de l’infection par le Virus Respiratoire Syncytial en période néonatale / Characterization and modulation of the innate immune response following Respiratory Syncytial Virus infection during the neonatal period

Drajac, Carole 04 July 2018 (has links)
Le Virus Respiratoire Syncytial (VRS) est responsable de 70 % des cas de bronchiolite chez les enfants de moins de cinq ans. La survenue de bronchiolites sévères chez le nourrisson est un facteur de risque de développement d’asthme en grandissant. Aucun vaccin contre le VRS n’est disponible chez l’Homme. Le système immunitaire inné est la première ligne de défense de l’organisme contre les infections. De plus, en interaction avec la flore bactérienne commensale des poumons, l’immunité innée participe à la maturation de la réponse immunitaire adaptative qui confère à l’individu une protection sur le long terme vis-à-vis des pathogènes. Afin d’expliquer la susceptibilité néonatale au VRS, nous avons caractérisé un nouveau mécanisme de contrôle de la réponse innée antivirale lors de l’infection de souriceaux. Nous avons également testé une nouvelle approche de modulation de la réponse immunitaire au VRS par le microbiote pulmonaire. Ainsi, mieux comprendre les mécanismes immunologiques et virologiques responsables de bronchiolites sévères en période néonatale permettra de développer des moyens de lutte sûrs et efficaces contre l’infection par le VRS. / Respiratory Syncytial Virus (RSV) is responsible for 70 % of bronchiolitis in children under five years old. Severe bronchiolitis in infants is a risk factor for asthma development. No vaccine against RSV is available in humans. The innate immune system is the first line of defense against infections. Moreover, in interaction with lung microbiota, innate immunity shapes adaptive immune response responsible for long-term protection against pathogens. To explain the susceptibility of young children to RSV, we characterized a novel regulatory mechanism of the innate antiviral response during neonatal RSV infection in the murine model. We also tested a new approach for modulating immune responses to RSV by the pulmonary microbiota. Thus, a better understanding of immunological and virological mechanisms responsible for severe bronchiolitis during the neonatal period will allow the development of safe and effective therapeutic strategies against RSV infection.
17

Sensing Interfacial Non-Faradaic and Faradaic Processes via Plasmonic-Enhanced Metallic Luminescence in Nano-Optoelectrodes

Zhao, Yuming 03 January 2024 (has links)
Metallic nanostructures supporting surface plasmon modes can concentrate optical fields, and enhance luminescence processes from the metal surface at plasmonic hotspots. Such nanoplasmonic metal luminescence contributes to the spectral background in surface-enhanced Raman spectroscopy (SERS) measurements and is helpful in bioimaging, nano-thermometry, and chemical reaction monitoring applications. Despite increasing interest in nanoplasmonic metal luminescence, little attention has been paid to investigating its dependence on voltage modulation. Also, the hyphenated electrochemical surface-enhanced Raman spectroscopy (EC-SERS) technique typically ignores voltage-dependent spectral background information associated with nanoplasmonic metal luminescence due to limited mechanistic understanding and poor measurement reproducibility. In this thesis, we combine the experimental observations and theoretical study on dynamic Faradaic & non-Faradaic modulated nanoplasmonic metallic luminescence and molecular vibrational Raman from hotspots at the electrode-electrolyte interfaces using multiple novel nano-optoelectrodes. Our work represents a critical step toward the general application of nanoplasmonic metal luminescence signals in optical voltage biosensing, hybrid optical-electrical signal transduction, and interfacial electrochemical monitoring. / Master of Science / Understanding the non-Faradaic and Faradaic process pathway is crucial for unraveling reaction mechanisms, developing efficient catalysts, designing bionsensing methodology, energy conversion and cellular stimulator (1-7). Advances in spectroscopic techniques( 8, 9) and computational models (3, 10) have facilitated the investigation of the non-Faradic and Faradaic processes. Unlike bulk reactions, interfacial electrochemical reactions occur in nanometer-thin layers (3, 11), necessitating highly sensitive detection methods. A significant challenge is background interference from bulk electrolytes and electrodes, often obscuring weak signals from the interfacial region – traditional spectroelectrochemistry struggles to match the high temporal resolution requirement due to noise (12, 13). Surface plasmons have become a promising solution for enhancing the sensitivity of spectroelectrochemical techniques (14, 15). Surface plasmons are collective oscillations of electrons at the metal-dielectric interface, which can focus and intensify optical fields at the nanoscale (16), boosting diverse nonlinear emission signals, including fluorescence, Raman scattering, and harmonic generation (17-23). By utilizing surface plasmons, spectroelectrochemistry techniques have shown promise in detecting interfacial activities with high sensitivity. In this thesis, we introduce a pioneering dual-channel in situ EC-SERS methodology, which harnesses the synergy between plasmon-enhanced vibrational Raman scattering (PE-VRS) and plasmon-enhanced electronic Raman scattering (PE-ERS) interfacial signals to monitor and analyze the Faradaic and non-Faradaic process at the electrode-electrolyte interfaces.
18

Modélisation mathématique de la dynamique de diffusion de bactéries résistantes aux antibiotiques : application au pneumocoque

Opatowski, Lulla 05 March 2009 (has links) (PDF)
L'objectif de cette thèse est de développer des outils de modélisation mathématique afin d'étudier la dynamique de transmission des souches de pneumocoque dans la communauté. La dynamique d'émergence et de diffusion de bactéries résistantes dans la population est difficile à anticiper : les phénomènes se produisent à différentes échelles (bactérie, hôte et population) et les bactéries circulent dans des environnements humains complexes (nombreux antibiotiques et vaccins). Dans ce cadre, la formalisation mathématique et la simulation peuvent contribuer à mieux comprendre et anticiper les phénomènes en jeu. Trois questions principales sont posées dans ce travail. Elles portent sur : l'effet d'une modification de l'exposition antibiotique sur la distribution des résistances du pneumocoque ; les conséquences de l'usage de vaccins conjugués sur les distributions de souches ; et l'étude de la dynamique d'incidence des méningites à pneumocoque. Pour y répondre, 4 modèles mathématiques compartimentaux spécifiques sont construits. Les résultats des simulations renforcent l'idée que l'exposition antibiotique est un facteur environnemental majeur pour la sélection des pneumocoques résistants aux antibiotiques. En particulier, ils mettent en évidence l'importance du choix des molécules antibiotiques utilisées et des doses prescrites sur la distribution des résistances dans la population. Ils suggèrent de plus que les virus hivernaux, la consommation antibiotique et l'épidémicité différenciée en fonction de la résistance pourraient expliquer en partie la dynamique des méningites à pneumocoque dans la population.

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