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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

Spectroscopie à corrélation de fluorescence multi-confocale : développement et application à l'étude de la réponse cellulaire au choc thermique / Multi-confocal fluorescence correlation spectroscopy and its application to the study of the cellular response to heat shock

Kloster-Landsberg, Meike 01 October 2012 (has links)
Le noyau d'une cellule est hétérogène par sa structure et son activité et beaucoup de ses composants interagissent de façon dynamique. Lors de l'étude de processus cellulaires comme la réponse au stress thermique, des expériences classiques de spectroscopie de corrélation de fluorescence (FCS), qui sont habituellement limitées à un seul volume d'observation, n'apportent que des résultats partiels à cause des informations spatiales manquantes. Ce mémoire de thèse présente une nouvelle technique de FCS multi-confocale (mFCS) qui permet des mesures FCS simultanées à différents endroits d'une cellule. La technique est basée sur l'emploi d'un modulateur spatial de lumière pour la création de plusieurs volumes d'observations distincts et d'une caméra ``electron-multiplying'' CCD (EMCCD) pour la détection en parallèle. La résolution spatiale ainsi que la sensibilité du système mFCS sont proches de celles d'un système FCS classique et en utilisant un mode d'acquisition particulier une résolution temporelle de $14mu s$ a pu être atteinte. La technique mFCS est appliquée à l'étude de la réponse cellulaire au stress thermique en observant le facteur de transcription heat shock factor 1 (HSF1), qui est un régulateur clé de la réponse au stress thermique. Des mesures mFCS dans des cellules vivantes révèlent des changements dans la dynamique de HSF1 pendant le choc thermique. Ces changements concernent l'affinité ainsi que l'homogénéité spatiale des interactions avec l'ADN. En outre, nous avons également évalué les performances d'une caméra CMOS-SPAD et testé le dispositif en tant que capteur alternatif pour la mFCS en cellules vivantes. / The cell nucleus is heterogeneous in its structure and activity and many of its components are in dynamic interactions with each other. When investigating the cellular response to an external signal, such as heat shock, standard fluorescence correlation spectroscopy (FCS) experiments, which are limited to one observation volume, do only give partial results because of the missing spatial information. This work introduces a novel multi-confocal FCS (mFCS) technique that allows simultaneous FCS measurements in different locations within a cell. It is based on the use of a spatial light modulator (SLM) to create several distinct observation volumes at a time and an electron-multiplying charge coupled device (EMCCD) camera to perform parallel detection. The spatial resolution as well as the sensibility of the mFCS system are close to that of a classical FCS setup and using a special readout mode, a temporal resolution of $14mu s$ is reached. The mFCS technique is applied to study the cellular response to thermal stress by monitoring the transcription factor heat shock factor 1 (HSF1), which is a key regulator of the heat shock response. mFCS experiments in living cells reveal changes in the dynamics of HSF1 upon heat shock. These changes concern the affinity as well as the spatial homogeneity of its interactions with DNA. Additionally, the performance of a CMOS-SPAD camera, consisting of an array of single photon avalanche diodes, is evaluated and the device is tested as an alternative detector for mFCS in living cells.
52

Subcellular Localization of Nicotiana tabacum TGA Transcription Factors / Subzelluläre Lokalisation von TGA Transkriptionfaktoren aus Nicotiana tabacum

Nickolov, Kaloian Iliev 30 January 2003 (has links)
Die Salicylsäure (SA) ist ein wichtiges Signalmolekül bei der Regulation der pflanzlichen Pathogenabwehr. as-1-ähnliche cis-Elemente in den Promotoren von vielen Abwehrgenen vermitteln SA- und auch Auxin-induzierbare Genexpression. Diese Elemente werden vom ASF-1/SARP-Proteinkomplex erkannt, dessen Hauptkomponenten DNA-Bindeproteine aus der TGA-Familie der pflanzlichen bZIP-Transkriptionsfaktoren sind. In dieser Arbeit wurden Fusionsproteine von TGA2.1, TGA2.2 und TGA1a mit GFP unter der Kontrolle des HBT-Promotors transient in Pflanzenprotoplasten oder stabil in transgenen Pflanzen exprimiert und direkt in lebenden Zellen über Fluoreszenz- und konfokale Laser-Scanning-Mikroskopie visualisiert. Bei den mikroskopischen Analysen konnte die Fluoreszenz der drei TGA-GFP-Fusionsproteine überwiegend im Kern (mit Ausnahme des Nukleolus) beobachtet werden. Allerdings ließen sich biochemisch mit Hilfe eines Antiserums gegen die beiden C Termini der TGA-Faktoren auch geringe Mengen von TGA2.1-GFP und TGA2.2-GFP in cytosolischen Extrakten der entsprechenden transgenen Pflanzen nachweisen. Fusionen der C terminalen Anteile von TGA2.2 und TGA1a an den C Terminus von CHS-GFP wurden bei transienter Expression ebenfalls im Cytosol beobachtet. Es konnte nicht abschließend geklärt werden, ob dass auf das Fehlen der NLS oder auf die Anwesenheit einer NES zurück zu führen ist. Die TGA-GFP-Fusionsproteine konnten das as 1-Element in vitro in Gelretardationsanalysen erkennen und in Form von Homo-oder Heterodimeren daran binden. Die TGA-GFP-Fusionsproteine waren auch in der Lage, die Expression des frühen (immediate-early) GST-Gens Nt103 in Blättern nach Induktion mit Salicylsäure oder Auxin zu beeinflussen. TGA2.1-GFP und TGA2.2-GFP zeigten im allgemeinen einen positiven Effekt auf die Nt103-mRNA-Menge (2-4-facher Anstieg verglichen mit dem Wildtyp), wobei sich der Effekt stärker auf die SA-induzierte Expression auswirkte als auf die 2,4-D-Proben. TGA1a-GFP schien die Expression von Nt103 in Blättern in beiden Fällen leicht negativ oder gar nicht zu beeinflussen. Die Mobilitätsparameter der verschiedenen TGA-GFP-Fusionsproteine im Kern wurden mit Hilfe von FCS, kombiniert mit CLMS, untersucht. Während die Mobilität des Kontrollproteins TetR-GFP, dass keine endogenen Interaktionpartner hat, einheitlich war, schienen Subfraktionen der TGA-GFP Fusionproteine in ihrer Mobilität beeinflusst. Generell konnte zwischen einer mobileren und einer weniger mobilen Fraktion unterschieden werden. Bei manchen Messungen waren die TGA-Faktoren im Kern sogar gänzlich immobil. Die relative Anteil von weniger mobilen, bzw. immobilen und mobilen TGA-faktoren unterschied sich in den unterschiedlichen analysierten Zelltypen (längliche und echte Epidermiszellen, Schießzellen, Trichomzellen). Um einen eindeutigen Effekt von Salizylsäure auf die Mobilität der TGA-Faktoren festzumachen, sind wegen der großen Variabilität weitere Messungen nötig.
53

Neue Einblicke in die SNARE-vermittelte Fusion: Detektion einzelner Proteoliposomen mit einem konfokalen Mikroskop / New insights into SNARE-mediated fusion: Detection of single proteoliposomes with a confocal microscope

Cypionka, Anna 17 December 2009 (has links)
No description available.
54

Single-molecule approaches reveal outer membrane protein biogenesis dynamics

Svirina, Anna, Chamachi, Neharika, Schlierf, Michael 01 March 2024 (has links)
Outer membrane proteins (OMPs) maintain the viability of Gram-negative bacteria by functioning as receptors, transporters, ion channels, lipases, and porins. Folding and assembly of OMPs involves synchronized action of chaperones and multi-protein machineries which escort the highly hydrophobic polypeptides to their target outer membrane in a folding competent state. Previous studies have identified proteins and their involvement along the OMP biogenesis pathway. Yet, the mechanisms of action and the intriguing ability of all these molecular machines to work without the typical cellular energy source of ATP, but solely based on thermodynamic principles, are still not well understood. Here, we highlight how different single-molecule studies can shed additional light on the mechanisms and kinetics of OMP biogenesis.
55

Fatores críticos de sucesso na aderência de processos de negócio de ERP às organizações do setor público

ELIHIMAS, Julliane Cristinne Mágero 20 August 2015 (has links)
Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2016-04-07T13:12:44Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Fatores Críticos de Sucesso na Aderência de Processos de Negócio de ERP às Organizações do Setor Público - Julliane Mágero.pdf: 2612858 bytes, checksum: ac5ae5d0b64ccb5859bf1434a201a7f7 (MD5) / Made available in DSpace on 2016-04-07T13:12:44Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Fatores Críticos de Sucesso na Aderência de Processos de Negócio de ERP às Organizações do Setor Público - Julliane Mágero.pdf: 2612858 bytes, checksum: ac5ae5d0b64ccb5859bf1434a201a7f7 (MD5) Previous issue date: 2015-08-20 / A implantação de sistemas integrados de gestão (ERP) juntamente com a Gestão de Processos de Negócio (BPM) têm se tornado uma expressiva abordagem para aumentar a eficiência e eficácia dos serviços prestados pelas organizações, especialmente as instituições públicas. Contudo, a implantação de sistemas ERP é um processo complexo e de alto risco para as empresas, as quais tem o BPM como ferramenta essencial de apoio para identificar a aderência dos requisitos de negócios específicos da instituição em relação aos requisitos funcionais do ERP. Sendo assim, o objetivo dessa pesquisa é analisar os desafios envolvidos na aderência dos processos de negócio de um ERP administrativo no setor público, com a proposta de identificar os fatores que são críticos para o seu sucesso, sob a ótica dos patrocinadores, líderes, analistas de negócio e usuários. Para compreender este problema a partir de uma perspectiva prática, foi realizado um estudo de caso exploratório em uma instituição pública de ensino superior que está implantando um sistema ERP. Foram realizadas entrevistas, observações e análise documental para coletar os dados, que foram analisados posteriormente. O estudo de caso exploratório propiciou a identificação dos fatores críticos de sucesso que influenciam, como facilitadores ou barreiras, na implantação dos sistemas integrados de gestão. Assim, a realização desse estudo e os resultados encontrados colaboraram para o aumento do conhecimento sobre quais os fatores influenciam na fase de aderência durante a implantação de um ERP, possibilitando a mitigação dos possíveis impactos negativos. / The implementation of integrated management systems (ERP) together with the Business Process Management (BPM) has become an expressive approach to increase the efficiency and effectiveness of services provided by organizations, especially public institutions. However, the implementation of ERP systems is a complex and risky process for companies, which have the BPM as an essential support tool to identify adherence to the specific business requirements of the institution in relation to functional ERP requirements. Thus, the objective of this research is to analyze the challenges involved in adherence of the business processes of an administrative ERP in the public sector, with the purpose of identifying the factors that are critical to its success, from the perspective of sponsors, leaders, business analysts and users. To understand this issue from a practical perspective, an exploratory case study was conducted in a public institution of higher education that is implementing an ERP system. Interviews were conducted, as well as observations and documental analysis for data collection, which were analyzed later. The exploratory case study led to the identification of critical success factors that influence as facilitators or barriers in the implementation of integrated management systems. Thus, the realization of this study and the results obtained contributed to increase the knowledge about which factors influence the adherence phase when deploying an ERP, enabling the mitigation of possible negative impacts.
56

Decoupled Lateral Directional Flight Control System Design Using Eigenstructure Assignment Method

Dixit, Girish G 10 1900 (has links) (PDF)
No description available.
57

An analysis of degraded communications in the Army's future force

Lindquist, Joseph M. 06 1900 (has links)
Approved for public release; distribution is unlimited / The US Department of Defense is currently pursuing the most comprehensive transformation of its forces since the early years of WWII. This transformation is a holistic approach to update both the equipment that the forces will fight its conflicts with and the way in which they will fight. This transformation relies heavily on fully networked air, ground and space based platforms. While many experts agree that in the course of the next 10 years communications equipment will emerge to support the networking of these systems, there remains much uncertainty on how operations will be effected if the technology does not mature enough to meet expectations. This research shows that even a 25 percent degradation in communications range could pose significant challenges for this Future Force. Additionally, even small delays (latencies greater than one minute) and constraints on network throughput can increase the Future Force casualties and the duration of battle. While the end result in all analysis shows that the Future Force is a superior element with the same battle end state-victory, the cost of that victory depends significantly on effective communications. / Captain, United States Army
58

Big Game Cats and Defining Football’s Value: College Football’s Popularity, Controversies, and Expansion

Himel, Matthew T 01 May 2015 (has links)
This thesis directly approaches intercollegiate football from a cultural perspective. The football’s popularity exploded during the Twentieth-Century. Television, merchandizing, and a national sporting culture are associated with this development. However, controversies often muddied the waters of that popularity. Football’s brutality, athletic scholarships, and controversies within athletics departments overshadowed the immense popularity of intercollegiate football. During the Twenty-First Century, several universities started new football programs. Two of which being Georgia State University and Southeastern Louisiana University. Given the context balancing popularity and controversy, the administrators demonstrated how the image of intercollegiate football has changed over the course of the past century. This thesis analyzes how the administrators sold the new football programs to their respective institutions and concludes that both universities emphasized the sport’s popularity, avoided controversy, recognized the large potential for financial loss, and concentrated the new programs benefit being increased indirect and intrinsic values.
59

Nanohydrodynamique au voisinage d'une surface solide : de la caractérisation expérimentale à l'équilibre aux conséquences sur la dynamique des systèmes chargés

Joly, Laurent 17 November 2005 (has links) (PDF)
Ce travail a pour objectif d'étudier l'influence des propriétés de surface sur la nanohydrodynamique de liquides simples au voisinage de parois solides.<br />Dans une première partie, nous avons développé une nouvelle méthode pour la détermination de la condition limite hydrodynamique (CLH) fondée sur la mesure, par spectroscopie de corrélation de fluorescence, du mouvement thermique de colloïdes confinés. Nous montrons que, sur des surfaces lisses, la CLH est influencée par les propriétés de mouillage de la paroi : tandis que l'hypothèse de non-glissement est respectée sur les parois mouillantes, nous observons un glissement nanométrique du liquide sur les parois non-mouillantes.<br />Dans une deuxième partie, nous avons exploré, à l'aide de simulations de dynamique moléculaire, les conséquences de ces modifications sur la dynamique des systèmes chargés. Sur des parois non-mouillantes, nous mettons en évidence la possibilité d'une forte amplification des différents effets électrocinétiques.
60

Nano-antennes optiques pour l'exaltation et le contrôle de la fluorescence moléculaire dans des volumes sub-longueur d'onde.

Aouani, Heykel 08 September 2011 (has links) (PDF)
Les nano-antennes optiques permettent la manipulation, le confinement et l'exaltation des champs électromagnétiques dans des volumes sub-longueur d'onde. Les applications de ces nano-objets concernent des domaines variés tels que les nano-sources de lumière, la photovoltaïque, la microscopie, la spectroscopie... Les propriétés physiques de ces nano-antennes dépendant essentiellement de leur nature, leurs tailles et leurs géométries, la caractérisation expérimentale de ces nano-objets est essentielle car elle permet d'en améliorer fortement le design et d'amplifier les réponses électromagnétiques. La problématique de ce travail de thèse concerne la caractérisation et l'exploitation des propriétés de nano-antennes optiques. Différentes techniques de caractérisation expérimentale de nano-antennes ont été développées au cours de cette thèse: spectroscopie de corrélation de fluorescence, suivi de dynamique temporelle de boîtes quantiques, spectroscopie sous saturation de fluorescence. Ces techniques ont été appliqués pour étudier différents types d'antennes optiques: microsphères diélectriques, nano-ouvertures simples et nano-ouvertures corruguées. Réciproquement, ces nano-antennes optiques ont été utilisées pour améliorer efficacement la détection de molécules fluorescentes en solution, avec des exaltations de fluorescence moléculaire supérieures à un facteur 100 et un contrôle de la directivité d'émission de fluorescence, ouvrant ainsi de nouvelles opportunités en biophotonique.

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