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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.
161

The memory-based paradigm for vision-based robot localization

Jüngel, Matthias 04 October 2012 (has links)
Für mobile autonome Roboter ist ein solides Modell der Umwelt eine wichtige Voraussetzung um die richtigen Entscheidungen zu treffen. Die gängigen existierenden Verfahren zur Weltmodellierung basieren auf dem Bayes-Filter und verarbeiten Informationen mit Hidden Markov Modellen. Dabei wird der geschätzte Zustand der Welt (Belief) iterativ aktualisiert, indem abwechselnd Sensordaten und das Wissen über die ausgeführten Aktionen des Roboters integriert werden; alle Informationen aus der Vergangenheit sind im Belief integriert. Wenn Sensordaten nur einen geringen Informationsgehalt haben, wie zum Beispiel Peilungsmessungen, kommen sowohl parametrische Filter (z.B. Kalman-Filter) als auch nicht-parametrische Filter (z.B. Partikel-Filter) schnell an ihre Grenzen. Das Problem ist dabei die Repräsentation des Beliefs. Es kann zum Beispiel sein, dass die gaußschen Modelle beim Kalman-Filter nicht ausreichen oder Partikel-Filter so viele Partikel benötigen, dass die Rechendauer zu groß wird. In dieser Dissertation stelle ich ein neues Verfahren zur Weltmodellierung vor, das Informationen nicht sofort integriert, sondern erst bei Bedarf kombiniert. Das Verfahren wird exemplarisch auf verschiedene Anwendungsfälle aus dem RoboCup (autonome Roboter spielen Fußball) angewendet. Es wird gezeigt, wie vierbeinige und humanoide Roboter ihre Position und Ausrichtung auf einem Spielfeld sehr präzise bestimmen können. Grundlage für die Lokalisierung sind bildbasierte Peilungsmessungen zu Objekten. Für die Roboter-Ausrichtung sind dabei Feldlinien eine wichtige Informationsquelle. In dieser Dissertation wird ein Verfahren zur Erkennung von Feldlinien in Kamerabildern vorgestellt, das ohne Kalibrierung auskommt und sehr gute Resultate liefert, auch wenn es starke Schatten und Verdeckungen im Bild gibt. / For autonomous mobile robots, a solid world model is an important prerequisite for decision making. Current state estimation techniques are based on Hidden Markov Models and Bayesian filtering. These methods estimate the state of the world (belief) in an iterative manner. Data obtained from perceptions and actions is accumulated in the belief which can be represented parametrically (like in Kalman filters) or non-parametrically (like in particle filters). When the sensor''s information gain is low, as in the case of bearing-only measurements, the representation of the belief can be challenging. For instance, a Kalman filter''s Gaussian models might not be sufficient or a particle filter might need an unreasonable number of particles. In this thesis, I introduce a new state estimation method which doesn''t accumulate information in a belief. Instead, perceptions and actions are stored in a memory. Based on this, the state is calculated when needed. The system has a particular advantage when processing sparse information. This thesis presents how the memory-based technique can be applied to examples from RoboCup (autonomous robots play soccer). In experiments, it is shown how four-legged and humanoid robots can localize themselves very precisely on a soccer field. The localization is based on bearings to objects obtained from digital images. This thesis presents a new technique to recognize field lines which doesn''t need any pre-run calibration and also works when the field lines are partly concealed and affected by shadows.
162

Ki-67, cd10, cd34, p53, cd117 e mastócitos no diagnóstico diferencial dos fibroadenomas celulares e na graduação dos tumores filóidesz / Ki-67, cd10, cd34, p53, cd117 and mast cells in differential diagnosis of cellular fibroadenomas and in the classfication of phyllodes tumors

Vilela, Maria Helena Tavares 09 October 2013 (has links)
Submitted by Marlene Santos (marlene.bc.ufg@gmail.com) on 2014-09-30T18:51:57Z No. of bitstreams: 2 Dissertação- Maria Helena Tavares Vilela-2013.pdf: 2276556 bytes, checksum: 772ad6ab585b17765e734a42bc50eb7e (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Jaqueline Silva (jtas29@gmail.com) on 2014-09-30T19:29:06Z (GMT) No. of bitstreams: 2 Dissertação- Maria Helena Tavares Vilela-2013.pdf: 2276556 bytes, checksum: 772ad6ab585b17765e734a42bc50eb7e (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2014-09-30T19:29:06Z (GMT). No. of bitstreams: 2 Dissertação- Maria Helena Tavares Vilela-2013.pdf: 2276556 bytes, checksum: 772ad6ab585b17765e734a42bc50eb7e (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2013-10-09 / The proper management of breast phyllodes tumors (PTs) remains challenging, due to the difficulty of the correct preoperative diagnosis. The aim of this study was to evaluate the usefulness of the Ki-67, CD10, CD34, p53, CD117 and the number of mast cells for the differential diagnosis between benign PTs and cellular fibroadenomas (CFs), and also at the grading of PTs. 51 primary PTs and 14 FCs were examined by immunohistochemistry (IH). Through the evaluation of the expression of CD117, greater epithelial expression was found at the FCs and an increased number of mast cells in benign TFs. The stromal expression of the Ki-67, CD10, CD34 and p53 showed relevance to the grading of PTs. / O manejo adequado dos tumores filóides (TFs) mamários continua desafiador, devido à dificuldade do diagnóstico pré-operatório correto. O objetivo deste estudo foi avaliar a utilidade do Ki-67, do CD34, do CD10, do CD117, da p53 e do número de mastócitos no diagnóstico diferencial entre os TFs benignos e fibroadenomas celulares (FCs), bem como na graduação dos TFs. Foram examinados 51 TFs primários e 14 FCs por imunohistoquímica (IH). Na marcação pelo CD117, houve maior expressão epitelial nos FCs e maior número de mastócitos nos TFs benignos. A expressão estromal do Ki-67, da p53, do CD10 e CD34 mostrou-se significante na graduação dosTFs.
163

Towards Single Molecule Imaging - Understanding Structural Transitions Using Ultrafast X-ray Sources and Computer Simulations

Caleman, Carl January 2007 (has links)
X-ray lasers bring us into a new world in photon science by delivering extraordinarily intense beams of x-rays in very short bursts that can be more than ten billion times brighter than pulses from other x-ray sources. These lasers find applications in sciences ranging from astrophysics to structural biology, and could allow us to obtain images of single macromolecules when these are injected into the x-ray beam. A macromolecule injected into vacuum in a microdroplet will be affected by evaporation and by the dynamics of the carrier liquid before being hit by the x-ray pulse. Simulations of neutral and charged water droplets were performed to predict structural changes and changes of temperature due to evaporation. The results are discussed in the aspect of single molecule imaging. Further studies show ionization caused by the intense x-ray radiation. These simulations reveal the development of secondary electron cascades in water. Other studies show the development of these cascades in KI and CsI where experimental data exist. The results are in agreement with observation, and show the temporal, spatial and energetic evolution of secondary electron cascades in the sample. X-ray diffraction is sensitive to structural changes on the length scale of chemical bonds. Using a short infrared pump pulse to trigger structural changes, and a short x-ray pulse for probing it, these changes can be studied with a temporal resolution similar to the pulse lengths. Time resolved diffraction experiments were performed on a phase transition during resolidification of a non-thermally molten InSb crystal. The experiment reveals the dynamics of crystal regrowth. Computer simulations were performed on the infrared laser-induced melting of bulk ice, giving a comprehension of the dynamics and the wavelength dependence of melting. These studies form a basis for planning experiments with x-ray lasers.
164

Analyse et méta-analyse des niveaux d'expression d'GF-R, c-erbB-2, Ki-67 et des micro-vaisseaux aux différents stades de développement des cancers bronchiques

Meert, Anne-Pascale 28 March 2007 (has links)
Dans un premier temps, nous avons réalisé des revues systématiques de la littérature avec méta-analyses des données de survie. Ceci nous a conduits à sélectionner 4 marqueurs de mauvais pronostic pour la survie des CBNPC: le récepteur au facteur de croissance épidermique (EGF-R), un autre récepteur de cette famille (c-erbB-2) ainsi que deux autres facteurs potentiellement témoins de leur activité, Ki-67 (impliqué dans la prolifération) et le nombre des micro-vaisseaux (témoins de la néoangiogenèse).<p>Dans une deuxième phase, nous avons étudié au laboratoire diverses questions sur des tumeurs bronchiques invasives.<p>Premièrement, nous avons investigué le mécanisme de surexpression d’EGF-R et de c-erbB-2 et évalué si des anomalies génétiques pouvaient prédire cette surexpression, en recourant à des techniques d’immunohistochimie et de FISH. Ceci nous a permis d’observer que, si la majorité des CBNPC réséqués présentent des anomalies génétiques d’EGF-R et/ou de c-erbB-2, une amplification de ces gènes n’est présente que dans une minorité d’entre eux et n’est pas strictement corrélée à l’expression protéique. D’autre part, la survie de ces patients exprimant ou ayant une anomalie génique d’EGF-R et/ou c-erbB-2 est plus courte sans atteindre le seuil de signification statistique.<p>Deuxièmement, nous avons recherché sur des tumeurs opérées d’éventuels liens entre les expressions d’EGF-R, de c-erbB-2 et de Ki-67. Aucune corrélation n’a été mise en évidence entre l’expression de ces 3 facteurs. Par contre, chez ces patients, l’expression de Ki-67 dans la tumeur s’est avérée être un facteur de mauvais pronostic pour la survie.<p>Troisièmement, nous avons voulu savoir si un de ces marqueurs (EGF-R) présentait une valeur pronostique dans un groupe plus restreint de tumeurs plus avancées, les CBNPC de stade III. Pour mener cette recherche sur des biopsies, nous avons d’abord démontré que l’évaluation des marqueurs biologiques (EGF-R, c-erbB-2 et Ki-67) sur biopsie ne différait pas de celle réalisée sur des tumeurs réséquées. Comme les résultats étaient équivalents, nous avons pu étudier EGF-R sur les biopsies de CBNPC au stade III et montrer qu’EGF-R n’était pas un facteur pronostique pour la survie dans ce groupe assez homogène de tumeurs avancées.<p>Dans la dernière phase, nous avons étudié des lésions représentatives des différents stades prénéoplasiques et néoplasiques précoces radiooccultes. Ces lésions ont été prélevées lors d’examens endoscopiques de photodétection. EGF-R, c-erbB-2, Ki-67 et le nombre des micro-vaisseaux ont été étudiés par immunohistochimie dans ces différents stades de lésions prénéoplasiques et néoplasiques précoces. Nous avons observé qu’EGF-R et Ki-67 sont statistiquement plus exprimés dans les dysplasies sévères et les carcinomes in que dans les dysplasies légères suggérant que, au moins pour ces 2 marqueurs, les dysplasies sévères se rapprochent plus des carcinomes in situ que des dysplasies légères. Alors que l’expression d’EGF-R est présente dès le stade de dysplasie sévère, une augmentation du nombre des micro-vaisseaux n’est présente qu’au stade de tumeurs micro-invasives. C-erbB-2 n’est quant à lui pas exprimé dans ces lésions bronchiques prénéoplasiques et néoplasiques précoces. <p>En conclusion, les facteurs biologiques, EGF-R, c-erbB-2 et Ki-67 et le nombre des micro-vaisseaux s’avèrent des facteurs de mauvais pronostic dans le CBNPC. La surexpression d’EGF-R et de c-erbB-2 dans les cancers réséqués résulte très rarement d’une amplification génique et nous n’avons pas trouvé dans ces tumeurs de corrélation entre l’expression des marqueurs moléculaires étudiés. Dans les tumeurs plus avancées de stade III, EGF-R n’est pas un facteur discriminant pour le pronostic. Les anomalies de certains de ces marqueurs (EGF-R et Ki-67) apparaissent précocement, dès les stades prénéoplasiques, avec un seuil se situant entre les lésions bronchiques de bas et de haut grades. La néoangiogénèse, évaluée par le nombre des micro-vaisseaux, s’observe à partir des cancers micro-invasifs tandis que c-erbB-2 n’apparaît qu’au stade invasif. Dans la séquence d’apparition des anomalies génétiques conduisant au cancer invasif, l’atteinte d’EGF-R précède la néoangiogénèse.<p> / Doctorat en sciences médicales / info:eu-repo/semantics/nonPublished
165

AI-based Multi-class Traffic Model Oriented to Freeway Traffic Control

Binjaku, Kleona, Pasquale, Cecilia, Sacone, Simona, Meçe, Elinda Kajo 23 June 2023 (has links)
In this extended abstract, we propose an Artificial Intelligence-based model dedicated to the representation of a multi-class traffic flow, i.e. a traffic flow in which different vehicle classes (at least cars and trucks) are explicitly represented, with the aim of using it for the development of freeway traffic control schemes based on ramp management. Specifically, the goal of this work is to develop a hybrid modelling technique in which a Machine Learning component and the multi-class version of METANET model are adopted to determine a better estimation and forecasting tool for freeway traffic. The resulting model is specifically devised in order to be included in a Model Predictive Control (MPC) scheme for the required traffic state prediction.
166

Transdisziplinäre Betrachtung I: Wie beeinflussen mentale Modelle des Menschen die Entwicklung und Nutzung technischer Systeme?

Bocklisch, Franziska 07 September 2023 (has links)
Die menschzentrierte Industrie der Zukunft wird durch die Zusammenführung transdisziplinärer Sicht- und Arbeitsweisen verschiedener Fachdisziplinen entstehen. Die Veröffentlichungsreihe 'Transdisziplinäre Betrachtungen' fasst wesentliche Themen im Spannungsfeld 'Mensch, Künstliche Intelligenz und Technik' in übersichtlicher Posterform zusammen. Die Betrachtungen dienen der einführenden Darstellung einer ganzheitlich-systemischen Betrachtungsweise des Bereichs „Mensch und Produktion“. 'Transdisziplinäre Betrachtungen I' widmet sich der Frage, wie mentale Modelle des Menschen den Technikentwicklungs- und Techniknutzungsprozess beeinflussen. Hierzu werden die zwei grundlegenden Rollen des Menschen im Zusammenhang mit der Technik dargestellt. Relevante psychologische Prozesse, u.a. kognitive Prozesse der menschlichen Informationsverarbeitung, werden benannt. Es wird anschaulich dargestellt und beschrieben, wie mentale Modelle des Menschen mit technischen Modellen und Systemen in Zusammenhang stehen (sollten).
167

Influence of Substitutions in the Binding Motif of Proline-Rich Antimicrobial Peptide ARV-1502 on 70S Ribosome Binding and Antimicrobial Activity

Brakel, Alexandra, Krizsan, Andor, Itzenga, Renke, Kraus, Carl N., Otvos Jr., Laszlo, Hoffmann, Ralf 18 January 2024 (has links)
Proline-rich antimicrobial peptides (PrAMPs) are promising candidates to treat bacterial infections. The designer peptide ARV-1502 exhibits strong antimicrobial effects against Enterobacteriaceae both in vitro and in vivo. Since the inhibitory effects of ARV-1502 reported for the 70 kDa heat-shock protein DnaK do not fully explain the antimicrobial activity of its 176 substituted analogs, we further studied their effect on the bacterial 70S ribosome of Escherichia coli, a known target of PrAMPs. ARV-1502 analogues, substituted in positions 3, 4, and 8 to 12 (underlined) of the binding motif D3KPRPYLPRP12 with aspartic acid, lysine, serine, phenylalanine or leucine, were tested in a competitive fluorescence polarization (FP) binding screening assay using 5(6)-carboxyfluoresceinlabeled (Cf-) ARV-1502 and the 70S ribosome isolated from E. coli BW25113. While their effect on ribosomal protein expression was studied for green fluorescent protein (GFP) in a cell-free expression system (in vitro translation), the importance of known PrAMP transporters SbmA and MdtM was investigated using E. coli BW25113 and the corresponding knockout mutants. The dissociation constant (Kd) of 201 16 nmol/L obtained for Cf-ARV-1502 suggests strong binding to the E. coli 70S ribosome. An inhibitory binding assay indicated that the binding site overlaps with those of other PrAMPs including Onc112 and pyrrhocoricin as well as the non-peptidic antibiotics erythromycin and chloramphenicol. All these drugs and drug candidates bind to the exit-tunnel of the 70S ribosome. Substitutions of the C-terminal fragment of the binding motif YLPRP reduced binding. At the same time, inhibition of GFP expression increased with net peptide charge. Interestingly, the MIC values of wild-type and DsbmA and DmdtM knockout mutants indicated that substitutions in the ribosomal binding motif altered also the bacterial uptake, which was generally improved by incorporation of hydrophobic residues. In conclusion, most substituted ARV-1502 analogs bound weaker to the 70S ribosome than ARV-1502 underlining the importance of the YLPRP binding motif. The weaker ribosomal binding correlated well with decreased antimicrobial activity in vitro. Substituted ARV-1502 analogs with a higher level of hydrophobicity or positive net charge improved the ribosome binding, inhibition of translation, and bacterial uptake.
168

Proliferation and expression of p53 in odontogenic tumours - An immunohistochemical analysis

Wassberger, Johanna, Yarahmadi, Mahtab January 2017 (has links)
Introduktion: Ameloblastom (AB), adenomatoid odontogen tumör (AOT), ameloblastiskt fibrom (AF) och odontogent fibrom (OF) är odontogena tumörer som innehåller epiteliala komponenter. Frekvensen av recidiv hos dessa varierar från låg förekomst till relativt hög förekomst. Syftet med denna studie är att undersöka om Ki-67, p53 och BRAF kan användas som prognostiska markörer i recidivmönstret hos dessa tumörer.Material och metod: Studien genomfördes genom immunohistokemi med monoklonala antikroppar av Ki-67, p53 och BRAF på respektive tumör. Tumörerna hämtades från avdelningen för Oral patologi på Malmö högskola. En statistisk analys utfördes med hjälp av Kruskal-Wallis envägs-ANOVA.Resultat: I de tio AB-fallen kunde en hög proliferation och en hög prevalens av muterade p53 ses. I de sju fallen av AOT kunde en måttligt hög proliferation och en generellt hög prevalens av muterade p53, jämförbara med värden för AB, ses. De sju fallen med AF och de fem fallen med OF visade båda en låg proliferation och en låg förekomst av muterade p53. Skillnaden mellan gruppen AB och AOT och gruppen AF och OF visade en signifikant högre infärgningsintensitet för både Ki-67 (p<0.001) och p53(p=0.001) för gruppen med AB och AOT.Konklusion: Proliferations index med Ki-67 och förekomst av p53-mutationer kan användas som en prognostisk markör för recidiv hos AB och AOT. Det är å andra sidan inte tillämpbart för AF och OF. / Introduction: Ameloblastoma (AB), adenomatoid odontogenic tumour (AOT), ameloblastic fibroma (AF) and odontogenic fibroma (OF) are all odontogenic tumours with an epithelial component. The recurrence rate for these odontogenic tumours varies from low frequencies to quite high frequencies. The aim of this study is to evaluate the expression of Ki-67, p53 and BRAF and the possibility of these antibodies acting as prognostic markers in the recurrence pattern of odontogenic tumours.Material and method: An immunohistochemical study using Ki67, p53 and BRAF monoclonal antibodies was performed on 29 paraffin blocks from the respective tumours obtained at the department of Oral Pathology in the Faculty of Odontology at Malmö University. Statistical analysis was performed with Kruskal-Wallis one-way ANOVA.Results: In the series of ten AB cases high proliferation activity and a high prevalence of p53 mutations was observated. In the seven AOT cases a moderately high proliferative activity as well as a generally high prevalence of p53 mutation, comparable to AB, was observed. The seven cases of AF and the five cases of OF demonstrated a low proliferative activity and a low prevalence of p53 mutation. The difference between AB and AOT versus AF and OF as two separate groups, showed a significantly higher staining intensity for both Ki-67 (p < 0.001) and p53 (p = 0.001) in AB and AOT as a group.Conclusion: Ki-67 proliferation index and p53-mutation status can be considered to be a prognostic marker for AB and AOT recurrence. This is, however, not applicable to AF and OF.
169

"Colonização gástrica por Helicobacter pylori associada à citotoxina do gene A (cagA): relação com proliferação celular e apoptose" / Helicobacter pylori (HP) gastric colozation and cytotoxin associated gene A (cagA) : relationship with cell proliferation and apoptosis

Darini, Elaine 09 September 2004 (has links)
HP, uma bactéria gram-negativa envolvida na patogênese do tecido gastroduodenal, foi classificada como carcinogênico classe I em 1994. Seus mecanismos são pouco entendidos, mas a presença da ilha de patogenicidade (PAI) é fator importante de virulência. PAI sugere aumento da proliferação celular, diminuindo a apoptose. A detecção do HP e da PAI (cagA) foi feita por PCR. Casos positivos são associados aos resultados histopatológicos, proliferação celular e apoptose. Detectamos HP em 37,0% (111/300), sendo 40,5% (45/111) dos pacientes cagA+. A relação proliferação celular/apoptose (P/A) mostra aumento em pacientes infectados por HP/cagA até 8,8 vezes maior no surgimento de doença gástrica grave / HP, a gram-negative bacterium involved in pathogenesis of gastroduodenal tissues, was classified as type I carcinogen in 1994. The mechanisms involved in carcinogenesis point to the pathogenicity island (PAI) as an important virulent factor. PAI suggests an increase in cell proliferation, attenuating apoptosis. HP detection and PAI were performed by using PCR. Positive results were associated to the histological findings, cell proliferation and apoptosis. We detected HP in 37,0% (111/300) and 40,5% (45/111) of the patients. A significant increase index appears between proliferation and apoptosis in those infected by HP/cagA+ with higher risk of 8,8 for the development of gastric cancer
170

"Colonização gástrica por Helicobacter pylori associada à citotoxina do gene A (cagA): relação com proliferação celular e apoptose" / Helicobacter pylori (HP) gastric colozation and cytotoxin associated gene A (cagA) : relationship with cell proliferation and apoptosis

Elaine Darini 09 September 2004 (has links)
HP, uma bactéria gram-negativa envolvida na patogênese do tecido gastroduodenal, foi classificada como carcinogênico classe I em 1994. Seus mecanismos são pouco entendidos, mas a presença da ilha de patogenicidade (PAI) é fator importante de virulência. PAI sugere aumento da proliferação celular, diminuindo a apoptose. A detecção do HP e da PAI (cagA) foi feita por PCR. Casos positivos são associados aos resultados histopatológicos, proliferação celular e apoptose. Detectamos HP em 37,0% (111/300), sendo 40,5% (45/111) dos pacientes cagA+. A relação proliferação celular/apoptose (P/A) mostra aumento em pacientes infectados por HP/cagA até 8,8 vezes maior no surgimento de doença gástrica grave / HP, a gram-negative bacterium involved in pathogenesis of gastroduodenal tissues, was classified as type I carcinogen in 1994. The mechanisms involved in carcinogenesis point to the pathogenicity island (PAI) as an important virulent factor. PAI suggests an increase in cell proliferation, attenuating apoptosis. HP detection and PAI were performed by using PCR. Positive results were associated to the histological findings, cell proliferation and apoptosis. We detected HP in 37,0% (111/300) and 40,5% (45/111) of the patients. A significant increase index appears between proliferation and apoptosis in those infected by HP/cagA+ with higher risk of 8,8 for the development of gastric cancer

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