Submitted by Maria Aparecida (cidazen@gmail.com) on 2017-04-26T12:29:41Z No. of bitstreams: 1 Bruno Araújo Serra Pinto.pdf: 5546725 bytes, checksum: 07839b14efcc510ac5ecfa62b980626e (MD5) / Made available in DSpace on 2017-04-26T12:29:41Z (GMT). No. of bitstreams: 1 Bruno Araújo Serra Pinto.pdf: 5546725 bytes, checksum: 07839b14efcc510ac5ecfa62b980626e (MD5) Previous issue date: 2017-04-07 / FAPEMA / Background: The epidemiological rise of metabolic syndrome (MS) is directly related to the exponential increase of added sugar consumption. Studies describes that MSmetabolic disorders, mainly insulin resistance and obesity, are related to development of oxidative stress, cognitive declines and dementias, and neuronal senescence acceleration. Even with several evidences correlating MS to neuronal damage, the molecular mechanisms involved are still unclear, and the endoplasmic reticulum stress (ER stress), in this context, could be placed like an intermediary condition that interconnects those morbidities. Objective: To investigate the deleterious effects of hippocampal ER stress about progression of cognitive, behavioral and motor declines in rats with metabolic syndrome-induced by sucrose-rich diet in different ages. Methods: Weaned Wistar rats were divided into 4 groups: two control groups (CTR, n = 7-9), fed a standard diet and followed up to 3 and 6-months-old, respectively; and two obese groups (HSD, n = 7), fed a sucrose-rich diet (25% sucrose) followed by the same periods. Was assessed in these groups: MS development; redox profile; Cognitive, behavioral and motor functions; And the hippocampal gene/protein expression of UPR sensors (Ire1α, Perk and Atf6), chaperones (Grp78, Grp94, Pdi, Calnexin and Calreticulin), neuronal plasticity (Bdnf), antioxidant defense (Nrf2), apoptosis (Bcl2, Chop and Parp-1) and senescence (p53 and p21). For aging control, rats at 20 months of age (OLD, n = 7) fed standard chow were included as aging control for gene/protein expression and neurological assessments. Results: The sucrose-rich diet was successful in establish the SM-phenotype. At 3 months, we observed central obesity even with lower energy intake, fasting and fed dysglycemia, hypertriglyceridemia, hapatic ectopic fat deposit, decreased lipolysis rates, glucose intolerance and hepatic insulin resistance. In unpublished data, we observed mild lipid peroxidation without exepressive antioxidant enzymes activity, and absence of peripheral insulin resistance. In animals with 6 months, we observed a deepening of metabolic dysfunctions encountered in 3-months-old. In addition we observed weight gain, free fatty acids, hyperinsulinemia, peripheral insulin resistance, increased lipid peroxidation, higher SOD, CAT and GPx reduction activity in 6-months-old rats. The lipolysis rate wasn't performed. Regarding the neurofunctional assessment at 3-months-old, the animals presented motor deficit and anxiogenic behavior, however without cognitive dysfunctions. In 6-months-animals, we observed anxiogenic behavior and important motor and cognitive impairments (learning and memory), similar to OLD group. Hippocampal molecular analysis revealed a different signaling between HSD groups of 3 and 6-months. In HSD at 3 months, we observed a switch-over from UPR-adaptive to pro-apoptotic signaling, marked by increased gene expression of Perk, Atf6 and Pdi A2 (adaptive), reduction of Grp78 and Bcl2, and increases of Chop and Caspase 3 (Apoptotic). In 6-months-HSD, we observed a complete failure of UPR adaptive signaling (UPR sensors and chaperones) and increased apoptotic signaling, featured by Bcl2 reduction and increased gene/protein expression of Chop. Additionally, we observed a reduction in the Bdnf gene expression and protein cleavage of Parp-1 compatible to calpain presence (necrosis/apoptosis marker). The expressions found in the 6-month-HSD were similar to OLD group, but the cell death markers (Chop and Calpain) were found only in HSD. As expected, senescence markers (p53 and p21) were increased in the OLD group and only p21 shown increased in HSD. Conclusions: Our data set supports that prolonged exposure to sucrose-rich diet promotes SM and oxidative stress, which disrupt hippocampal ER homeostasis, leading to senescence acceleration and cell death, and subsequently leads to severe cognitive, behavioral and motor impairments. / Introdução: O crescimento epidemiológico da síndrome metabólica (SM) está diretamente relacionado ao exponencial aumento do consumo de açucares de adição. Estudos descrevem que as desordens metabólicas que compõem a SM, principalmente a resistência insulínica e obesidade, estão relacionadas ao desenvolvimento de estresse oxidativo, declínios cognitivos, demências e aceleração da senescência neuronal. Mesmo com diversas evidências correlacionando a SM a danos neuronais, os mecanismos moleculares envolvidos ainda não são totalmente conhecidos. Neste contexto, o estresse do retículo endoplasmático (ERE) pode ser apontado como uma condição intermediária que interconecta estas morbidades. Objetivo: Investigar os efeitos deletérios do ERE hipocampal sobre a instalação de declínios cognitivos, comportamentais e motores em ratos com síndrome metabólica induzida por dieta rica em sacarose em diferentes faixas etárias. Métodos: Ratos Wistar com 21 dias de vida (desmame) foram divididos em 4 grupos: dois grupos controle (CTR, n = 7-9), alimentados com uma dieta padrão e acompanhados até os 3 e 6 meses de idade, respectivamente; e dois grupos obeso (HSD, n = 7), alimentados com dieta rica em sacarose (sacarose a 25%) acompanhados pelos mesmos períodos. Foi avaliado nos grupos: desenvolvimento de SM; perfil redox; funções cognitivas, comportamentais e motoras; e expressão gênica/proteica hipocampal de sensores da UPR (Ire1α, Perk e Atf6), chaperonas (Grp78, Grp94, Pdi, Calnexina e Calreticulina), plasticidade neuronal (Bdnf), defesa antioxidante (Nrf2), apoptose (Bcl2, Chop e Parp-1) e senescência (p53 e p21). Como um controle de envelhecimento, ratos com 20 meses de idade (OLD, n = 7) alimentados com dieta padrão foram incluídos aos experimentos de expressões gênica/proteica e avaliações neurológicas. Resultados: A dieta rica em sacarose teve sucesso em estabelecer o fenótipo de SM. Com 3 meses, o grupo HSD desenvolveu obesidade central mesmo com menor ingestão energética, disglicemia em estados de jejum e alimentado, hipertrigliceridemia, acúmulo de gordura ectópica hepática, diminuição da taxa de lipólise, intolerância à glicose e resistência hepática à insulina. Em dados não publicados, observamos discreta peroxidação lipídica sem expressiva atividade de enzimas antioxidantes e sem resistência insulínica periférica. Nos animais com 6 meses, observamos um aprofundamento das disfunções metabólicas dos animais de 3 meses. Adicionalmente, observamos ganho de peso, ácidos graxos livres, hiperinsulinemia, resistência insulínica periférica, maior peroxidação lipídica, maior atividade das enzimas SOD, CAT e redução da GPx. No que se refere à avaliação neurofuncional, aos 3 meses de idade, o grupo HSD apresentou déficit motor e comportamento ansiogênico, no entanto sem disfunções cognitivas. Contudo, nos animais de 6 meses observamos comportamento ansiogênico e importantes prejuízos motores e cognitivos (aprendizado e memória), semelhantes ao grupo OLD. A análise molecular hipocampal evidenciou uma sinalização diferente entre os grupos HSD de 3 e 6 meses. No HSD com 3 meses, observamos uma transição da sinalização adaptativa da UPR para a pró-apoptótica, marcada pelo aumento das expressões gênicas de Perk, Atf6 e Pdi A2 (adaptativa), redução da Grp78 e aumento da Chop e Caspase 3 (apoptótica). No HSD de 6 meses, observamos uma falência total da sinalização adaptativa da UPR (sensores da UPR e chaperonas), e aumento da sinalização apoptótica, caracterizada pela redução do Bcl2 e aumento da expressão gênica/proteica de Chop. Adicionalmente, observamos também redução da expressão gênica do Bdnf, redução da expressão proteica de Grp94 e clivagem proteica do Parp-1 compatível com a presença de Calpaína (marcador de necrose/apoptose). As expressões encontradas no HSD de 6 meses foram semelhante as alterações observadas no grupo OLD, mas os fatores de morte celular (Chop e Calpaína) foram encontrados apenas no HSD. Como esperado, os marcadores de senescência (p53 e p21) estavam aumentados no grupo OLD e apenas o p21 se mostrou aumentado no HSD. Conclusões: Nosso conjunto de dados apoia que a exposição prolongada à dieta rica em sacarose promove SM e estresse oxidativo, que perturba a homeostase do RE hipocampal, acarretando aceleração da senescência e morte celular, e subsequentes prejuízos cognitivos, comportamentais e motores.

Obesity-associated metabolic disorders are amongst the most prevalent causes of death worldwide. Understanding how obesity leads to the development of the Metabolic Syndrome (MetS) and cardiovascular disease (CVD) will enable the development of novel therapies that dissociate obesity from its cardiometabolic complications. Our laboratory views the functional capacity of white adipose tissue (WAT), the organ designed for safe lipid storage, as a key factor in the development of MetS and CVD. At a genetically-defined stage of the aberrant WAT expansion that occurs during obesity, adipocytes undergo a functional failure, resulting in an impaired control of serum free fatty acid (FFA) concentration. In such setting, FFAs and their metabolic derivatives accumulate in other organs, where they cause lipotoxicity, leading to the development of insulin resistance and CVD. We therefore aim to understand the pathophysiological mechanisms that induce adipocyte dysfunction. The past two decades of research have established the immune system as an important regulator of WAT function. The number of adipose tissue macrophages (ATMs), the most abundant immune cell type in WAT, increases during obesity, resulting in WAT inflammation. Multiple genetic and pharmacological intervention studies of murine models of obesity have assigned a causal link between ATM pro-inflammatory activation and WAT dysfunction. However, while the propagation of inflammation in ATMs during obesity has been extensively studied, factors triggering ATM inflammatory activation are less clear. Recently, our lab has observed lipid accumulation in the ATMs isolated from obese mice. Lipid-laden ATMs were pro-inflammatory, leading us to hypothesise that aberrant lipid build-up in macrophages triggers WAT inflammation during obesity. This thesis expands on the initial findings from our lab and describes two novel mechanisms that potentially contribute to lipid-induced inflammatory activation of ATMs. In chapter 3, the role of de novo phosphatidylcholine (PC) synthesis pathway during lipotoxicity in macrophages is addressed. The first part of the chapter demonstrates that lipotoxic environment increased de novo PC synthesis rate in bone marrow-derived macrophages (BMDMs) and ATMs, and that loss of rate-limiting enzyme in de novo PC synthesis pathway, CTP:phosphocholine cytidylyltransferase a (CCTa) diminished saturated FFA-induced inflammation in BMDMs. In the second part, I show that macrophage-specific CCTa deletion did not impact on the development of WAT inflammation or systemic insulin resistance, but had a minor benefitial effect on hepatic gene transcription during obesity. Chapter 4 develops on recent observations of interactions between sympathetic nerves and macrophages in WAT. In the first part of the chapter, I demonstrate that stimulating B2-adrenergic receptor (B2AR), the main receptor for sympathetic neurotransmitter norepinephrine in macrophages, enhanced intracellular triglyceride storage by up-regulating diacylglycerol O-acyltransferase 1 (Dgat1) gene expression in BMDMs. The second part of the chapter shows that macrophage-specific B2AR deletion did not modulate systemic glucose and lipid metabolism during obesity, but mice lacking B2ARs in macrophages demonstrated augmented hepatic glucose production on a chow diet. Furthermore, systemic B2AR blockade or macrophage-specific B2AR deletion in mice did not affect the thermogenic response to cold exposure. Chapter 5 includes the characterisation of B2AR stimulation-induced changes to the global cellular proteome of BMDMs, and a subsequent validation of the role of candidate transcription factors in regulating B2AR agonism-induced gene expression in BMDMs.

Le mélanome est le cancer cutané le plus meurtrier. Il est issu de la transformation maligne des mélanocytes et se dissémine rapidement dans l'organisme sous forme de métastases. A ce stade, ce cancer est réfractaire à pratiquement toutes les thérapies. Ainsi, l'identification de nouvelles cibles thérapeutiques est donc incontournable pour la mise en place de biothérapies spécifiques dans le mélanome. Dans ce contexte, nous nous sommes intéressés au facteur de transcription E2F1 qui joue un rôle prépondérant dans le cycle cellulaire. Plus récemment, il lui a été identifié divers rôles dans les fonctions cellulaires. Ainsi, nous avons cherché à caractériser son implication dans le mélanome. Nous avons observé que E2F1 est faiblement exprimé dans les cellules saines de la peau. En revanche, elle est fortement exprimée dans le mélanome, et est corrélée à un mauvais pronostic clinique. Ainsi, nous avons montré que son inhibition réduisait la viabilité de cellules de mélanomes in vitro et in vivo dû à un arrêt du cycle cellulaire de la sénescence et d'une apoptose. Ces processus semblent être dépendants de la voie p53. Ce travail a permis de caractériser E2F1 comme une potentielle cible thérapeutique dans le mélanome non muté p53. En parallèle, nous avons initié une collaboration avec le Dr Slama-Schwok dont l'étude portait sur un composé appelé NS1, un inhibiteur de la NO-Synthase. Ce composé présente une activité anti-mélanome in vitro. En effet, il induit un stress du réticulum endoplasmique lui même conduisant à une autophagie partielle et une mort des cellules par apoptose. Ce projet ouvre de nouvelles perspectives pour le traitement du mélanome métastatique. / Melanoma is the most deadly form of skin cancer. It originates from malignant transformation of melanocytes and quickly disseminates as metastasis through the body. At this stage, this cancer is refractory to almost all therapies. Thus, new therapeutic target identification is needed for setting up specific biotherapies against melanoma. In this context, we focused on E2F1 transcription factor which plays a critical role in cell cycle. Recently, it was also implicated in several cell functions. So we aimed at characterizing its implication in melanoma. We observed that E2F1 is weakly expressed in normal skin cells. On the contrary, it is strongly expressed in melanoma and its expression correlates with a bad clinical prognosis. We also showed that E2F1 inhibition decreased melanoma cell viability in vitro and in vivo, as a result of cell cycle arrest, senescence and apoptosis. These processes seem to depend on p53 pathway. With this work we characterized E2F1 as a potential therapeutic target in non-mutated p53 melanoma. In parallel, we initiated a collaboration with Dr Slama-Schwok for studying NS1 compound, a NO-synthase inhibitor. This compound presents an in vitro anti-melanoma activity. Indeed, it induces endoplasmic reticulum stress, which leads to partial autophagy and cell death by apoptosis. This work opens new perspectives for metastatic melanoma treatment.

Die Studie befasst sich mit der Adaption der Artikulation als Folge einer insgesamt zweiwöchigen Veränderung der Vokaltraktgeometrie durch einen künstlichen Gaumen. Ziel der Arbeit ist zu untersuchen, ob die Adaption auf artikulatorische oder akustische Ziele hin erfolgt. Die Produktionen der Sprecher wurden während der Adaptionszeit regelmäßig akustisch und per elektromagnetischer Artikulographie aufgenommen. Akustische Analysen haben gezeigt, dass die Vokalproduktion sofort nach Perturbationsbeginn adaptiert wird. Für die Adaption der Frikative benötigen die Sprecher mehr Zeit, in einigen Fällen ist die zweiwöchige Adaptionszeit nicht ausreichend. Wenn die Daten nach Sprecher und Aufnahme getrennt betrachtet werden, nehmen die Produktionen einzelner Phoneme abgrenzbare Regionen im akustischen Raum ein. Der Einfluss der auditiven Rückmeldung ist stärker bei Vokalen mit weniger linguo-palatalem Kontakt als bei Vokalen mit viel Kontakt. Bei den Frikativen scheint die auditive Rückmeldung vor allem für die Sibilantenproduktion von Bedeutung zu sein. Generall hat die Adaption zum Ziel, die Abstände zwischen den Lauten beizubehalten oder zu vergrößern. Untersuchungen zur Artikulation des /u/ zeigen, dass die Sprecher über die Sitzungen hinweg motorisch äquivalente Strategien benutzen (Lippenvorstülpung versus Hebung des Zungenrückens). Messungen des Rucks für artikulatorische Gesten deuten darauf hin, dass der artikulatorische Aufwand nach Perturbationsbeginn steigt und zum Ende der Perturbation hin wieder fällt. Die Fähigkeit der Sprecher zu kompensieren wenn keine auditive Rückmeldung vorhanden ist, zeigt, dass Sprecher über artikulatorische Repräsentationen verfügen. Die Tatsache, dass motorisch äquivalente Strategien von den Sprechern genutzt werden, unterstützt jedoch akustische Repräsentationen der Phoneme. Die Schlussfolgerung, die aus der Untersuchung gezogen wird, ist daher, dass artikulatorische Repräsentationen beim Sprecher existieren, dass sie aber vor allem der Bewegungsorganisation dienen. Sobald das akustische Resultat nicht mehr das gewünschte ist, beginnen die Sprecher, die Artikulation zu verändern. / The present study describes the results of a 2 week perturbation experiment where speakers'' vocal tract shape was modified due to the presence of an artificial palate. The aim of the work is to investigate whether speakers adapt towards acoustic or articulatory targets. Speakers were recorded regularly over the adaptation time via electromagnetic articulography and acoustics. Immediately after perturbation onset speakers'' auditory feedback was masked with white noise in order to investigate speakers'' compensatory behaviour when auditory feedback was absent. The results of acoustic measurements show that in vowel production speakers compensate very soon. The compensation in fricatives takes longer and is in some cases not completed within the two weeks. Within a session and for each speaker the sounds can be distinguished solely by acoustic parameters. The difference between the session when no auditory feedback was available and the session when auditory feedback was available was greater for vowels with less palatal contact than for vowels with much palatal contact. In consonant production auditory feedback is primarily used in order to adapt sibilant productions. In general, adaptation tries to keep or enlarge the articulatory and acoustic space between the sounds. Over sessions speakers show motor equivalent strategies (lip protrusion vs. tongue back raising) in the production of /u/. Measurements of tangential jerk suggest that after perturbation onset there is an increase in articulatory effort which is followed by a decrease towards the end of the adaptation time. The compensatory abilities of speakers when no auditory feedback is available suggest that speakers dispose of an articulatory representation. The fact that motor equivalent strategies are used by the speakers, however, supports acoustic representations of speech. It is therefore concluded that articulatory representations belong to the speech production tasks. However, since they are modified as soon as the acoustic output is not the desired one any more, they rather function in the domain of movement organisation and the acoustic representations dominate.

<p>The nasal passages are constantly exposed to both air- and bloodborne foreign compounds. In particular, the olfactory mucosa is demonstrated to be susceptible to a variety of drugs and chemicals. In this thesis, mechanisms involved in tissue-selective toxicity in the olfactory mucosa of rodents have been investigated using the olfactory toxicant 2,6-dichlorophenyl methylsulphone (2,6-diClPh-MeSO₂) as a model compound. Comparative studies were performed with the non-toxic 2,5-dichlorophenyl methylsulphone (2,5-diClPh-MeSO₂) and the reasons for the strikingly different toxicity were investigated. </p><p>A strong bioactivation and protein adduction of 2,6-diClPh-MeSO₂ in olfactory microsomes and S9-fractions of rodents was demonstrated. In contrast, no significant metabolic activation of 2,5-diClPh-MeSO₂ was observed and the bioactivation in the liver for both chlorinated isomers was negligible. <i>In vitro</i> studies with recombinant yeast cell microsomes expressing mouse cytochrome P450 2A5 (CYP2A5) demonstrated a metabolic activation of 2,6-diClPh-MeSO₂. The 2,6-diClPh-MeSO₂-induced lesions and CYP2A5 expression preferentially occurred in Bowman’s glands and sustentacular cells of the olfactory mucosa. A significant depletion of glutathione (GSH) in the olfactory mucosa was demonstrated <i>in vivo</i>, while no changes were observed in the liver. There was a rapid induction of the endoplasmic reticulum (ER)-specific chaperone Grp78, activation of the ER-specific caspase-12 and the downstream caspase-3 in the Bowman’s glands. Electron microscopy revealed swelling of ER and mitochondria and a lost integrity of the Bowman’s glands. </p><p>Based on these results, the proposed mechanism for 2,6-diClPh-MeSO₂-induced toxicity in the olfactory mucosa is bioactivation by CYP2A5 into a reactive intermediate causing protein adduction and GSH-depletion. This is initiating a sequence of downstream events of ER-stress, changes in ion homeostasis, ultrastructural organelle disruption and apoptotic signalling. In spite of the initial apoptotic signals, the terminal phase of apoptosis seemed to be blocked and necrotic features occurred. The predominant expression of CYP2A5 in the olfactory mucosa is proposed to play a key role for the tissue- and cell-specific toxicity induced by 2,6-diClPh-MeSO₂.</p>

The nasal passages are constantly exposed to both air- and bloodborne foreign compounds. In particular, the olfactory mucosa is demonstrated to be susceptible to a variety of drugs and chemicals. In this thesis, mechanisms involved in tissue-selective toxicity in the olfactory mucosa of rodents have been investigated using the olfactory toxicant 2,6-dichlorophenyl methylsulphone (2,6-diClPh-MeSO2) as a model compound. Comparative studies were performed with the non-toxic 2,5-dichlorophenyl methylsulphone (2,5-diClPh-MeSO2) and the reasons for the strikingly different toxicity were investigated. A strong bioactivation and protein adduction of 2,6-diClPh-MeSO2 in olfactory microsomes and S9-fractions of rodents was demonstrated. In contrast, no significant metabolic activation of 2,5-diClPh-MeSO2 was observed and the bioactivation in the liver for both chlorinated isomers was negligible. In vitro studies with recombinant yeast cell microsomes expressing mouse cytochrome P450 2A5 (CYP2A5) demonstrated a metabolic activation of 2,6-diClPh-MeSO2. The 2,6-diClPh-MeSO2-induced lesions and CYP2A5 expression preferentially occurred in Bowman’s glands and sustentacular cells of the olfactory mucosa. A significant depletion of glutathione (GSH) in the olfactory mucosa was demonstrated in vivo, while no changes were observed in the liver. There was a rapid induction of the endoplasmic reticulum (ER)-specific chaperone Grp78, activation of the ER-specific caspase-12 and the downstream caspase-3 in the Bowman’s glands. Electron microscopy revealed swelling of ER and mitochondria and a lost integrity of the Bowman’s glands. Based on these results, the proposed mechanism for 2,6-diClPh-MeSO2-induced toxicity in the olfactory mucosa is bioactivation by CYP2A5 into a reactive intermediate causing protein adduction and GSH-depletion. This is initiating a sequence of downstream events of ER-stress, changes in ion homeostasis, ultrastructural organelle disruption and apoptotic signalling. In spite of the initial apoptotic signals, the terminal phase of apoptosis seemed to be blocked and necrotic features occurred. The predominant expression of CYP2A5 in the olfactory mucosa is proposed to play a key role for the tissue- and cell-specific toxicity induced by 2,6-diClPh-MeSO2.

Dans le cadre de la réduction des dimensions des technologies CMOS, le module de jonction apparaît comme un point bloquant pour l'amélioration des performances. En particulier, la hauteur de barrière entre le siliciure et le silicium limite le courant passant du transistor. Cette thèse adresse spécifiquement la problématique du contrôle de la hauteur de barrière suivant deux directions. D'une part, nous étudions l'intérêt d'une modification du métal formant le siliciure. D'autre part, nous évaluons le potentiel des techniques de ségrégation de dopants pour la modulation de la hauteur de barrière. Dans un premier temps, nous démontrons les difficultés liées à l'intégration des siliciures de type n (ErSi). Par ailleurs, nous mettons en évidence le fort potentiel du siliciure de platine (PtSi). En effet, ce matériau présente une stabilité thermique supérieure au siliciure de référence (NiSi) et montre une faible barrière à l'injection de trous. De plus, nous montrons que les techniques de ségrégation de dopants permettent d'obtenir de faibles hauteurs de barrières pour l'injection des électrons. Le PtSi apparaît donc comme un candidat à fort potentiel pour les futures technologies CMOS. Après avoir montré les inconvénients majeurs posés par l'intégration auto-alignée du PtSi grâce au procédé standard par eau régale, nous proposons une nouvelle méthode de retrait sélectif basée sur la transformation du métal non réagi en un germaniure facilement retiré par des chimies conventionnelles. En conclusion, nous intégrons le PtSi dans un procédé de fabrication industriel afin de démontrer des performances électriques à l'état de l'art des technologies CMOS les plus avancées.

No description available.

Higher Order Statistics (HOS) and Second Order Statistics (SOS) approaches have certain advantages and disadvantages in signal processing applications. HOS approach provides more statistical information for non-Gaussian signals. On the other hand, SOS approach is more robust to the estimation errors than the HOS approach, especially when the number of observations is small. In this thesis, HOS and SOS approaches are jointly used in order to take advantage of both methods. In this respect, the joint use of HOS and SOS approaches are introduced for online calibration of sensor arrays with arbitrary geometries. Three different problems in online array calibration are considered and new algorithms for each of these problems are proposed. In the first problem, the positions of the randomly deployed sensors are completely unknown except the two reference sensors and HOS and SOS approaches are used iteratively for the joint Direction of Arrival (DOA) and sensor position estimation. Iterative HOS-SOS algorithm (IHOSS) solves the ambiguity problem in sensor position estimation by observing the source signals at least in two different frequencies and hence it is applicable for wideband signals. The conditions on these frequencies are presented. IHOSS is the first algorithm in the literature which finds the DOA and sensor position estimations in case of randomly deployed sensors with unknown coordinates. In the second problem, narrowband signals are considered and it is assumed that the nominal sensor positions are known. Modified IHOSS (MIHOSS) algorithm uses the nominal sensor positions to solve the ambiguity problem in sensor position estimation. This algorithm can handle both small and large errors in sensor positions. The upper bound of perturbations for unambiguous sensor position estimation is presented. In the last problem, an online array calibration method is proposed for sensor arrays where the sensors have unknown gain/phase mismatches and mutual coupling coefficients. In this case, sensor positions are assumed to be known. The mutual coupling matrix is unstructured. The two reference sensors are assumed to be perfectly calibrated. IHOSS algorithm is adapted for online calibration and parameter estimation, and hence CIHOSS algorithm is obtained. While CIHOSS originates from IHOSS, it is fundamentally different in many aspects. CIHOSS uses multiple virtual ESPRIT structures and employs an alignment technique to order the elements of rows of the actual array steering matrix. In this thesis, a new cumulant matrix estimation technique is proposed for the HOS approach by converting the multi-source problem into a single source one. The proposed algorithms perform well even in the case of correlated source signals due to the effectiveness of the proposed cumulant matrix estimate. The iterative procedure in all the proposed algorithms is guaranteed to converge. Closed form expressions are derived for the deterministic Cram&acute / er-Rao bound (CRB) for DOA and unknown calibration parameters for non-circular complex Gaussian noise with unknown covariance matrix. Simulation results show that the performances of the proposed methods approach to the CRB for both DOA and unknown calibration parameter estimations for high SNR.

ABSTRACT MICROARRAY APPLICATIONS FOR DETERMINATION OF THE EFFECTS OF EMODIN ON BREAST CANCER CELL LINES Ekenel Qomi, Emilia M.S., Department of Biotechnology Supervisor: Prof. Dr. Mesude Iscan Co-Supervisor: Assoc. Prof. Dr. Nursen &Ccedil / oruh February 2012, 191 pages Cancer is a genetic disease that is characterized by uncontrolled cells growth. Breast cancer is a type of cancer originating from breast tissue. Some breast cancers are sensitive to hormones such as estrogen which makes it possible to treat them by blocking the effects of these hormones in the target tissues. These require less aggressive treatment than hormone negative cancers. Breast cancers without hormone receptors, are higher-risk, and are treated more aggressively. The aim of our study is to investigate the effect of emodin on MCF-7 which is ER (estrogen receptor) positive, and MDA-MB-231 (ER negative) cancerous cell lines. Emodin which is a phytoestrogen component, extracted from rheum (genus) plant, has been reported to suppress the growth of tumor in some clinical situation, and it&rsquo / s found that emodin induced apoptosis through the decrease of Bcl-2/Bax ratio and the increase of cytoplasm cytochrome c concentration in human breast cancer Bcap-37 cells. Comparing the effect of emodin between ER positive and ER negative cells at the molecular level was investigated by Microarray analysis of gene expressions using Affymetrix Human Genome U133 plus 2.0 Array. The microarray data analysis was performed by using BRB-Array Tools, v.4.2.0. GST and its classes / Alpha, Mu, Pi, Theta, Sigma, Omega, Zeta and Kappa is our interested genes because of its role in regulating susceptibility to cancer, by their ability to metabolize reactive electrophilic intermediates to usually less reactive and more water soluble glutathione conjugates. And also its have a role in detoxifying the damage caused by oxidative stress which is a result of the radiotherapy. v The differentially expressed genes from emodin treated and untreated control breast cancer cell lines were compared after normalization and filtering and annotated, it was shown that the top 10 highly (significantly) varied genes belong to the biological processes such as (namely) cell cycle, cell division, cell proliferation, mitosis and meiosis, this insure the relation of emodin to the cell growth processes in the cancerous cells. The analysis of the change on the cell growth confirmed the anti-tumor effect of emodin. About the effect of emodin treatment on MCF-7 and MDA-MB-231 cancerous cell lines separately / Both cells its significant genes was belong to cell growth biological processes, in MCF-7 cells in-addition other biological processes was shown, for example / stimulus to estradoil response, and the metabolism of xenobiotic by cytochrome p450, so CYP1A1 gene code for a protein which is used in emodin metabolism. The varied gene number was nearly 4400 gene from the scatter plot result in MCF-7 cells while in MDA-MB-231 cells it was nearly 3400 gene, these result insured the effect of emodin as a phytoestrogenic component as MCF-7 cells are ER positive cells, so emodin bind to the ER in MCF-7 cells and affected more gene number than MDA-MB-231. More number of GST enzyme classes changed in MCF-7 cells than MDA-MB-231, and the effect of emodin as anti-cancer showed different change of GST genes between MCF-7 and MDA-MB-231. The results confirmed by network analysis done, to find the most related genes to our top 10 regulated gene list, and these genes were analyzed / most of them where in our gene list, and their regulation after emodin treatment analyzed and the result was supported to emodin as anti-tumor and phytoestrogenic component.