Finally, another new 0.5V fully differential wideband amplifier, which can be used in the wideband modulator, has been proposed. The gate-input two-stage amplifier employs a DC common-mode feedback circuit that uses a Miller-amplified capacitor for its frequency compensation. With the proposed technique, the power consumption of the low-voltage amplifier is drastically reduced. / Furthermore, a new dynamic CM level shifting technique for low-voltage CT delta-sigma modulators that employ a return-to-open feedback DAC is reported in the thesis. The technique maintains a stable CM level at the amplifier's inputs for this type of modulators. Simulation results show that it improves the modulator's SNDR by 11%. / In this thesis, we present research works on developing a low-voltage delta-sigma modulator with a wide signal bandwidth. Specifically, a 0.5V complex low-pass continuous-time (CT) third-order delta-sigma modulator that has a single-sided signal bandwidth of 1MHz, targeting for application in Bluetooth receivers, is presented without using any internal voltage boosting techniques which are potentially harmful to the reliability of the device. The wide bandwidth of the modulator at this low supply voltage is enabled by a special common-mode (CM) level arrangement in the system level and by new low-voltage amplifies. Realized in a 0.13mum CMOS process the proposed modulator achieves a 61.9-dB peak signal-to-noise-and-distortion ratio at the nominal supply of 0.5V with 3.4mW consumption, and occupies an active area of 0.9mm2. The modulator achieves the best figure-of-merit among its class. / The development of low-voltage design techniques for analog circuits has recently received a lot of attention due to the continuous shrinking of the supply voltage in modern CMOS technologies, which is projected to reduce to 0.5V for low power applications within ten years in the International Technology Roadmap for Semiconductor. This thesis focuses on developing circuit techniques for low-voltage delta-sigma modulator, a functional block that is widely used in mixed-signal integrated circuits. Several delta-sigma modulators operating at supply voltages below 0.9V have been reported in the open literature. However, none of them supports a signal bandwidth wider than 100kHz with a reasonable performance. / He, Xiaoyong. / Adviser: Kong Pang Pun. / Source: Dissertation Abstracts International, Volume: 72-01, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 104-111). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. Ann Arbor, MI : ProQuest Information and Learning Company, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. Ann Arbor, MI : ProQuest Information and Learning Company, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

FtsZ é homóloga de tubulina, presente em quase todas as bactérias, que se autoassocia em filamentos que formam uma estrutura chamada anel Z dentro das células. O anel Z quando formado recruta de um macrocomplexo proteico chamado divisomo, que é responsável pela síntese do septo de divisão, formando duas células filhas. Diversos moduladores se ligam diretamente a FtsZ regulam sua polimerização, controlando o momento e o local onde o anel Z é formado. MciZ é um peptídeo de 40 aminoácidos expresso durante a esporulação de Bacillus subtilis e inibe a formação do do anel Z na célula mãe. O objetivo do presente trabalho foi estudar a interação entre as proteínas FtsZ e MciZ e investigar os mecanismos envolvidos na inibição da polimerização de FtsZ por MciZ. Através de uma triagem genética, usando uma biblioteca de mutantes de ftsZ, identificamos treze mutações em ftsZ que conferiram resistência à superexpressão de MciZ in vivo. Sete delas eram capazes de crescer na presença e na ausência da superexpressão de MciZ e as outras seis se mostraram dependentes da superexpressão de MciZ. A partir da coexpressão e copurificação do complexo FtsZ:MciZ, observamos que todas as proteínas mutantes ainda continuavam interagindo com MciZ in vitro. O Kd estimado para a interação entre as proteínas foi de 150±50nM, e mostrou-se que MciZ não se liga nem ao CTP (C-Terminal Peptide) de FtsZ, nem compete com GTP para a ligação no mesmo sítio. Usando construções truncadas de MciZ, determinou-se que o N-terminal da proteína (resíduos 1 ao 27) é suficiente para inibição. A partir das estruturas tridimensionais de MciZ (RMN) e do complexo FtsZ:MciZ (cristalografia de raios x), determinou-se que MciZ é um peptídeo desenovelado, que assume uma estrutura terciária ao interagir através da sua α-hélice H2 e folha-β B2 com a α-hélice H10 e a folha-β S9 de FtsZ. MciZ mostrou-se capaz de reduzir o tamanho dos protofilamentos de FtsZ de forma subestequiométrica, gerando fragmentos menores de filamentos. Proporções de MciZ:FtsZ de 1:10 foram suficientes para extinguir completamente o anel Z, confirmando a inibição subestequiométrica também in vivo. A conservação da inibição da fusão FtsZ-MciZ e a cinética de despolimerização de FtsZ induzida por MciZ provaram que MciZ não é um simples sequestrador. Marcações fluorescentes de MciZ sugeriram que o peptídeo é capaz de interagir com o anel Z in vivo, e também decorar feixes de FtsZ in vitro, formando focos localizados frequentemente na ponta dos filamentos. Cossedimentações com polímeros de FtsZ mostraram a presença de MciZ ou da fusão FtsZ-MciZ. Apesar de MciZ induzir o aumento da atividade GTPáscia específica de FtsZ, a ausência de hidrólise de GTP não eliminou o efeito subestequiométrico de MciZ. Nossos resultados em conjunto mostram que MciZ é um capeador dos filamentos de FtsZ, bloqueando a elongação pela ponta menos e bloqueando o anelamento entre protofilamentos / FtsZ is a tubulin-like protein present in most bacteria, that self-assembles into filaments forming a structure known as Z-ring in the cells. Following formation, the Z- ring recruits a protein macrocomplex, the divisome, which is responsible by the division septum synthesis, resulting in two daughter cells. Many modulators interact directly to FtsZ, regulating its polymerization and controlling the time and place of the Z-ring formation. MciZ is a 40-amino-acid peptide that is expressed during sporulation in Bacillus subtilis and inhibits the formation of the Z-ring in the mother-cell. The aim of this work was to study the interaction between FtsZ and MciZ proteins, and to investigate the mechanisms involved in FtsZ inhibition by MciZ. Applying a genetic screening, using an ftsZ mutant library, we identified 13 mutations on ftsZ that conferred resistance to MciZ overexpression in vivo. Seven of them were able to grow either in the presence or absence of MciZ overexpression, and the other six showed to be dependent on it. With the co-expression and co-purification of the FtsZ:MciZ complex, we observed all mutant proteins still interact with MciZ in vitro. Estimated Kd for the interaction was 150±50nM, and it was demonstrated that MciZ does not bind to FtsZ CTP (C-Terminal Peptide), nor does it compete with GTP for the same binding site. Using truncated versions of MciZ, it was determined that its N-terminal (residues 1 to 27) is sufficient for the inhibition. Based on the tridimensional structure of MciZ (NMR) and of the FtsZ:MciZ complex (x- ray crystallography), it was determined that MciZ is an unstructured peptide that assumes a tertiary structure by interacting with FtsZ α-helix H10 and β-sheet S9 through its α-helix H2 and β-sheet B2. MciZ was able to reduce the size of FtsZ protofilaments in a substoichiometric manner, generating smaller fragmented filaments. 1:10 ratios of MciZ:FtsZ were sufficient to completely extinguish the Z-ring, thus confirming the substoichiometric inhibition in vivo as well. The inhibition of FtsZ polymerization by the FtsZ-MciZ fusion and the FtsZ depolymerization kinetics induced by MciZ proved that MciZ is not a simple sequesterer. Fluorescent dyeing of MciZ suggests the peptide is able to interact with the Z-ring in vivo, as well as decorate FtsZ bundles in vivo, forming localized spots frequently at the filaments\' ends. Co- sedimentations with FtsZ polymers showed the presence of MciZ or of the FtsZ-MciZ fusion. Despite MciZ-induced increase in specific GTPase activity of FtsZ, the lack of GTP hydrolysis did not eliminate the substoichiometric effect of MciZ. Combined, our results show that MciZ is an FtsZ filament capper, blocking elongation at the minus end and blocking the annealing between protofilaments

In this PhD Thesis I present some methods for characterizing PA-LCoS microdisplays. It is useful to fully characterize this type of devices for evaluating its performance required in different applications. We have tested its validity in different applications such as diffractive optics elements (DOEs). Finally we apply these microdisplays in a full holographic data storage scheme using a photopolymer as holographic recording medium. We evaluate the capability of PVA/AA photopolymer for this holographic data storage system that incorporates as a novelty a convergent correlator geometry.

L’athérosclérose est une maladie inflammatoire chronique de la paroi vasculaire à évolution lente et silencieuse dont les principaux facteurs de risque sont les dyslipidémies, l’obésité, le diabète et le tabagisme. Les macrophages jouent un rôle crucial dans le développement et la progression de cette maladie. Ils sont issus de la différentiation des monocytes et ils ne constituent pas une population homogène. On peut reconnaître au moins deux sous-populations: les macrophages pro-inflammatoire M1 et les macrophages alternatifs ou M2 qui montrent des propriétés anti-inflammatoires. Les fonctions des macrophages sont régulées par des facteurs de transcription. Mon laboratoire d’accueil a réalisé une analyse transcriptomique sur les facteurs de transcription régulés dans les macrophages alternatifs et parmi les plus induits dans les M2 il y a NOR1 (Neuron-derived Orphan Receptor 1) et TLE1 (Transducin Like Enhancer of Split 1). Pour cette raison nous les avons choisis pour en étudier le rôle dans les macrophages alternatifs humains. Etude de l’expression et rôle de NOR1 dans les macrophages alternatifsNOR1 fait partie de la famille NR4A3 ensemble à deux autres membres, Nurr1 et Nur77 : les trois sont exprimés dans les macrophages au sein de la lésion d’athérosclérose humaine. Cependant l’expression et le rôle de NOR1 dans les macrophages alternatifs n’a pas encore été étudié. En utilisant le model en vitro des macrophages primaires alternatifs humains polarisée en présence de l’IL-4, nous avons démontré que l’expression de NOR1 est induite dans les macrophages M2 chez l’homme, tandis que cette régulation n’est pas vérifiée chez la souris. D’ailleurs l’expression de NOR1 est plus importante dans les zones de la lésion atherosclerotique humaine enrichies par les macrophages CD68+MR+ . En utilisant l’approche de diminution de l’expression de NOR1 par un siRNA spécifique, nous démontrons que l’expression de certaines marqueurs de la polarisation alternative tels que Mannose Receptor (MR), Interleukin-1 receptor antagonist (IL1Ra), CD200 receptor (CD200R), coagulation factor XIII A1 polypeptide (F13A1), interleukin 10 (IL10) and the Peroxisome Proliferator-Activated Receptor (PPARg) sont diminués. De plus, l’expression et l’activité de la matrix metallopeptidase 9 (MMP9) sont induites suite au silencing de NOR1, cette régulation est confirmé par l’approche de surexpression de NOR1 par infection adenovirale. Ces données identifient NOR1 parmi les facteurs de transcription induits dans les macrophages alternatifs humains et permettent de mettre en évidence comme NOR1 soit capable de modifier le phénotype alternatif des macrophages.Etude de l’expression et fonctions potentielles de TLE1 dans les macrophages alternatifsTLE1, appartenant à la grande famille appelée chez la Drosophile avec le nome de Groucho, est connu pour être un répresseur incapable de se fixer directement à l’ADN et que par conséquence agit par interaction avec des autres facteurs de transcription. Aucune donnée n’est disponible quant à l’expression ou aux fonctions de TLE1 dans les macrophages. Nos résultats montrent que TLE1 est parmi les facteurs de transcription les plus exprimés dans les macrophages alternatifs humains. Cette régulation est aussi observée dans les macrophages de souris. Nous avons aussi montré que TLE1 est fortement exprimé dans les zones enrichies en macrophages M2 au sein de la plaque athérosclérotique humaine ainsi que dans les macrophages à phénotype mixte qui infiltrent le tissu adipeux (ATM). Nous avons caractérisé l’expression génique de TLE1 dans les patients obèses avec ou sans diabète et nous montrons que l’expression de TLE1 varie selon le statut métabolique du donneur. / Atherosclerosis is an inflammatory disease in which macrophages play a crucial role. Macrophages are derived from the differentiation of circulating monocytes and they are not an homogenous population. We can distinguish at least two types of macrophages: The pro-inflammatory M1 macrophages and the alternative anti-inflammatory macrophages M2. Functions of macrophages are controlled by transcriptional factors. My laboratory has realised a transcriptomic analysis of transcriptional factors differently regulated among RM and M2 macrophages. Among the most regulated transcriptional factors there is NOR1 (Neuron-derived Orphan Receptor 1) and TLE1 (Transducin Like Enhancer of Split 1). According to these data, we have chose these two transcriptional factors in order to determine their role in human alternative macrophages. The neuron-derived orphan receptor 1 (NOR1) is induced upon human alternative macrophage polarization and stimulates the expression of markers of the M2 phenotypeThe neuron-derived orphan receptor 1 (NOR1), together with Nur77 and Nurr1, is a member of the NR4A orphan nuclear receptor family expressed in human atherosclerotic lesion macrophages. However, the expression and the functions of NOR1 in human alternative macrophages have not been studied yet. Using an in vitro model of IL-4 polarized primary human alternative macrophages we demonstrate that NOR1 expression increased in alternative M2 macrophages in humans but not in mice. Moreover NOR1 expression is also most abundant in CD68+MR+ alternative macrophage-enriched areas of human atherosclerotic plaques in vivo. Silencing NOR1 expression in human alternative macrophages decreases the expression of a panel of M2 markers such as the Mannose Receptor (MR), Interleukin-1 receptor antagonist (IL1Ra), CD200 receptor (CD200R), coagulation factor XIII A1 polypeptide (F13A1), interleukin 10 (IL10) and the Peroxisome Proliferator-Activated Receptor (PPARg). Moreover, expression and enzymatic activity of MMP9 are induced by NOR1 silencing in M2 macrophages, a regulation confirmed in NOR1 gain of function experiments. These data identify NOR1 among the transcription factors induced during alternative differentiation of human macrophages and demonstrate that NOR1 modifies the alternative macrophage phenotype. Study of TLE1 expression and potential functions in human alternative macrophagesTLE1 is a member of the Groucho family and it is mainly described as a transciptional co-repressor. Although lacking in DNA binding activity of their own, this protein is recruited to gene promoters through interaction with other factors. No data are available regarding the expression or role of TLE1 in macrophages. Our results show that TLE1 is among the highest expressed transcriptional factors in human alternative macrophages. This regulation is verified also in murine macrophages. Histological analysis showed that TLE1 expression in human carotid atherosclerotic lesions in vivo co-localizes with the macrophage marker CD68 and the alternative maker MR. Q-PCR analysis of macrophage-enriched areas isolated by LCM showed that the mRNA levels of TLE1 are higher in zones of alternative CD68+MR+ macrophages compared to zones enriched in CD68+MR- macrophages. Moreover we have shown that TLE1 expression is higher in adipose tissue macrophages (ATM) compared to resting macrophages isolated from blood of the same patients. Finally we have characterised the mRNA expression of TLE1 in obese patients affected or not by diabetes and we have shown that TLE1 expression is influenced by the metabolic state of the patients.

Graduation date: 2005

Delta-sigma analog-to-digital converters traditionally have been used for low speed, high resolution applications such as measurements, sensors, voice and audio systems. Through continued device scaling in CMOS technology and architectural and circuit level design innovations, they have even become popular for wideband, high dynamic range applications such as wired and wireless communication systems. Therefore, power efficient wideband low power delta-sigma data converters that bridges analog and digital have become mandatory for popular mobile applications today. In this dissertation, two architectural innovations and a development and realization of a state-of-the-art delta-sigma analog to digital converter with effective design techniques in both architectural and circuit levels are presented. The first one is timing-relaxed double noise coupling which effectively provides 2nd order noise shaping in the noise transfer function and overcomes stringent timing requirement for quantization and DEM. The second one presented is a noise shaping SAR quantizer, which provides one order of noise shaping in the noise transfer function. It uses a charge redistribution SAR quantizer and is applied to a timing-relaxed lowdistortion delta-sigma modulator which is suitable for adopting SAR quantizer. Finally a cascade switched capacitor delta-sigma analog-to-digital converter suitable for WLAN applications is presented. It uses a noise folding free double sampling technique and an improved low-distortion architecture with an embedded-adder integrator. The prototype chip is fabricated with a double poly, 4 metal, 0.18μm CMOS process. The measurement result achieves 73.8 dB SNDR over 10 MHz bandwidth. The figure of merit defined by FoM = P/(2 x BW x 2[superscript ENOB]) is 0.27 pJ/conv-step. The measurement results indicate that the proposed design ideas are effective and useful for wideband, low power delta-sigma analog-to-digital converters with low oversampling ratio. / Graduation date: 2012 / Access restricted to the OSU Community at author's request from June 19, 2012 - June 19, 2013

In this thesis, a novel Direct-Charge-Transfer (DCT) integrator structure is proposed, which can settle much faster than regular switch-capacitor integrators. A new Spread-Spectrum Dynamic Element Matching (SS-DEM) algorithm is also introduced, which can effectively spread or shape the nonlinearity error of multi-bit DAC in the feedback path, thus improve the SNDR and THD performance of overall delta-sigma modulators. A three-bit quantizer design example is presented, which is embedded in a MASH2-0 structure delta-sigma modulator prototype and has been fabricated in AMI CMOS 1.5μm technology. Testing results indicate this quantizer works well. / Graduation date: 2004

In this thesis various subjects at the crossroads of quantummechanics and device physics are treated, spanning from afundamental study on quantum measurements to fabricationtechniques of controlling gates for nanoelectroniccomponents. Electron waveguide components, i.e. electronic componentswith a size such that the wave nature of the electron dominatesthe device characteristics, are treated both experimentally andtheoretically. On the experimental side, evidence of partialballistic transport at room-temperature has been found anddevices controlled by in-plane Pt/GaAs gates have beenfabricated exhibiting an order of magnitude improvedgate-efficiency as compared to an earlier gate-technology. Onthe theoretical side, a novel numerical method forself-consistent simulations of electron waveguide devices hasbeen developed. The method is unique as it incorporates anenergy resolved charge density calculation allowing for e.g.calculations of electron waveguide devices to which a finitebias is applied. The method has then been used in discussionson the influence of space-charge on gate-control of electronwaveguide Y-branch switches. Electron waveguides were also used in a proposal for a novelscheme of carrierinjection in low-dimensional semiconductorlasers, a scheme which altogether by- passes the problem ofslow carrier relaxation in suchstructures. By studying aquantum mechanical two-level system serving as a model forelectroabsorption modulators, the ultimate limits of possiblemodulation rates of such modulators have been assessed andfound to largely be determined by the adiabatic response of thesystem. The possibility of using a microwave field to controlRabi oscillations in two-level systems such that a large numberof states can be engineered has also been explored. A more fundamental study on quantum mechanical measurementshas been done, in which the transition from a classical to aquantum "interaction free" measurement was studied, making aconnection with quantum non-demolition measurements.

<p>In this thesis various subjects at the crossroads of quantummechanics and device physics are treated, spanning from afundamental study on quantum measurements to fabricationtechniques of controlling gates for nanoelectroniccomponents.</p><p>Electron waveguide components, i.e. electronic componentswith a size such that the wave nature of the electron dominatesthe device characteristics, are treated both experimentally andtheoretically. On the experimental side, evidence of partialballistic transport at room-temperature has been found anddevices controlled by in-plane Pt/GaAs gates have beenfabricated exhibiting an order of magnitude improvedgate-efficiency as compared to an earlier gate-technology. Onthe theoretical side, a novel numerical method forself-consistent simulations of electron waveguide devices hasbeen developed. The method is unique as it incorporates anenergy resolved charge density calculation allowing for e.g.calculations of electron waveguide devices to which a finitebias is applied. The method has then been used in discussionson the influence of space-charge on gate-control of electronwaveguide Y-branch switches.</p><p>Electron waveguides were also used in a proposal for a novelscheme of carrierinjection in low-dimensional semiconductorlasers, a scheme which altogether by- passes the problem ofslow carrier relaxation in suchstructures. By studying aquantum mechanical two-level system serving as a model forelectroabsorption modulators, the ultimate limits of possiblemodulation rates of such modulators have been assessed andfound to largely be determined by the adiabatic response of thesystem. The possibility of using a microwave field to controlRabi oscillations in two-level systems such that a large numberof states can be engineered has also been explored.</p><p>A more fundamental study on quantum mechanical measurementshas been done, in which the transition from a classical to aquantum "interaction free" measurement was studied, making aconnection with quantum non-demolition measurements.</p>

Dissertation (Ph.D.)--Auburn University,2006. / Abstract. Vita. Includes bibliographic references (p.110-113).