In this thesis, we focus on the position inversion algorithm for infrared (IR) seekers with reticles. The IR seeker system is composed of a reticle, an IR sensor and the optical/electronic systems. The pattern on a reticle is specially designed and is made of both transparent and opaque materials. It is placed right in front of the focal plane of the IR optical imaging system. The area of the IR seeker is comparable to that of an IR sensor. The instantaneous received power is proportional to the overlap integral of infrared image and the reticle¡¦s transmittance function. The target is assumed to be quasi-stationary. When the target is idle in space the infrared detector will receive a one-dimension periodical signal. It is a quite difficult problem to obtain the desired target location in 2-D space from the 1-D infrared seeker waveform. We propose a general inversion algorithm that will handle both amplitude/frequency modulation (AM/FM) modulated as well as other more complicated IR reticles. An IR target in space can be of any location (X, Y coordinate) and of any size (or intensity). Our idea is to perform a search in the 3-D parametric space. After calculating all possible situations, we compare the simulated waveforms with the measured one and find the best fit. We are able to reduce to just search the 2-D positional space by applying a low-pass filter to the measured waveform before processing. We further speed up the convolution calculation by using the fast Fourier transform (FFT). We are able to complete our search in less time for the reticle to rotate half a cycle. Thus, the inversion algorithm is done in real time and is suitable for the field installation. We also can apply this method to help design the reticles for IR seekers based on success rate of identical targets under various situations. Normally it is highly impossible to obtain the original 2-D image from its modulated 1-D signal. In our case, IR images made of just a few bright spots are relatively simple. It allows us to perform the 2-D inversion when only the positional parameters of the targets are needed.

A desidroepierosterona (DHEA) é um hormônio esteroide produzido pelas glândula adrenal e gônadas em humanos. Diversas evidencias do efeitos anti-obesidade, antiinflamatórios e antioxidativos, além de ser precursor dos esteroides sexuais. No presente trabalho foi avaliando o efeito do DHEA sobre a citotoxicidade induzida 0,5mM de palmitato em miotubos L6, usando 2 concentrações distintas para o esteroide, uma próxima à fisiológica (10nM) e outra supra-fisiológica (100nM) por 12h. Foram avaliados parâmetros: viabilidade celular, apoptose, vias intracelulares envolvidas na apoptose, no estresse de retículo endoplasmatico e estado de estresse oxidativo. Os resultados obtidos foram, para ambas as concentrações de DHEA a redução do estresse de reticulo induzido por palmitato via Perk/eif2α/CHOP. Além disso o DHEA impediu o aumento da expressão de iNOS e de proteína nitradas induzidas por palmitato. A partir dos resultados concluímos que o DHEA, tem efeitos anti-apoptótico e regulador da UPR. Alem do DHEA ter sido eficaz na redução do estresse oxidativo. / Dehydroepierosterone (DHEA) is a steroid hormone produced by the adrenal gland and gonads in humans. Several evidences of the antiobesity, anti-inflammatory and antioxidative effects, besides being precursor of the sexual steroids. In the present study, the effect of DHEA on the 0.5mM induced cytotoxicity of palmitate in L6 myotubes was evaluated, using 2 different concentrations for the steroid, one physiological (10nM) and one supra-physiological (100nM) for 12h. The following parameters were evaluated: cell viability, apoptosis, intracellular pathways involved in apoptosis, endoplasmic reticulum stress and oxidative stress state. The results obtained were, for both concentrations of DHEA, reduction of the stress of reticulo induced by palmitato via Perk / eif2α / CHOP. In addition, DHEA prevented increased expression of iNOS and nitrite protein induced by palmitate. From the results we conclude that DHEA has anti-apoptotic and UPR regulatory effects. In addition to DHEA, it has been effective in reducing oxidative stress.

L’enzim 3-hidroxi-3-metilglutaril CoA reductasa o HMGR catalitza la reacció irreversible de reducció del HMG-CoA a mevalonat. Aquesta molècula, el mevalonat, es el primer intermediari específic de la ruta del mevalonat, una de les dues rutes biosintètiques de la síntesi de compostos isoprenoides en plantes. Els isoprenoides, també anomenats terpenoides, son un grup de molècules molt diversificat, no nomes pel que respecta a la seva funció, sinó també en estructura. A les plantes, s’han descrit mes de 29000 isoprenoides, amb funcions que van des de la formació i manteniment dels teixits fins a l’adaptació al medi. L’HMGR has estat objecte d’una gran quantitat d’estudis a llevats I animals, I s’ha descrit com el pas limitant pel que fa a la ruta de síntesi de colesterol. En aquests dos tipus d’organisme, el control sobre l’activitat de l’HMGR es molt complex, incloent diversos mecanismes de regulació com ara fosforilació, proteòlisi regulada o control transcripcional. En plantes, es conegut que l’HMGR es l’enzim que catalitza el pas limitant en la biosíntesi d’isoprenoides de la ruta del MVA. Al genoma d’Arabidopsis thaliana, trobem dos gens que codifiquen per tres isoformes diferents de l’HMGR. Les dues isoformes codificades al gen HMG1, difereixen entre elles únicament en una regió extra de 50 aminoàcids a la zona N-terminal de la proteïna, i degut a aquesta diferencia, han estat nominades d’acord amb això. D’aquesta manera trobem HMGR1S o isoforma curta de la proteïna, i HMGR1L o isoforma llarga. Ambdues isoformes es troben localitzades a la membrana del reticle endoplasmàtic (RE) però, mentre HMGR1L es troba present en una distribució uniforme dins la xarxa de túbuls i cisternes d’aquest orgànul, HMGR1S s’acumula específicament en unes vesícules associades amb aquesta xarxa. Aquest punt va esser demostrat gracies a la utilització d’un marcador de RE. Plantes transgèniques transformades amb una construcció quimèrica on el domini catalític de l’HMGR1S ha estat substituït per la proteïna verda fluorescent (GFP) han mostrat que aquestes vesícules son especifiques dels cotiledons, i que tenen una morfologia fusiforme. Estructures similars van ser trobades en plantes transgèniques que expressen la proteïna quimèrica GFP-HDEL, un altre marcador de la xarxa de RE. Aquestes vesícules van ser nomenades ER-bodies, i se sap que estan implicades en defensa i adaptació al medi ambient. Experiments de colocalització in planta han permès establir que la HMGR es troba present en aqeusts ER-bodies, i per tant aquest enzim podria estar implicat en la morfogènesi del RE o en la síntesi d’isoprenoides específics per a defensa. Anàlisis bioquímics d’activitat enzimàtica especifica HMGR en cèl•lules d’Arabidopsis van mostrar que l’activitat es troba disminuïda en situacions d’estres, sigui aquest biòtic o abiòtic, suggerint un reclutament de molecules d’HMGR cap als ER-bodies. Els nostres resultats suggereixen que, l’HMGR, una proteïna molt estudiada a nivell enzimàtic, presenta una funció paral•lela important per a l’estructuració del RE, que alhora es important enfront la resposta de la planta a estres, sense descartar, però, que al mateix temps l’HMGR podria estar implicada en la creació d’un entorn subcel•lular específic on la captació d’altres proteïnes amb activitat enzimàtica podria portar a la síntesi de compostos isoprenoides específics. / "Analysis of HMG-CoA Reductase of Arabidopsis thaliana: implication in the morphogenesis of the endoplasmic reticulum" The enzyme 3-hydroxi-3-methylglutharyl CoA Reductase or HMGR catalyzes the irreversible reaction of reduction of HMG-CoA to mevalonate, the first specific intermediate product of the mevalonate pathway, one of the two biosynthetic pathways of isoprenoid compounds in plants. Isoprenoid compoundsare a group of molecules with an extreme diversification. In plants, more than 29000 different isoprenoid have been identified, with completely different functions that range from formation and maintenance of tissues to adaptation to the environment. The HMGR has been extensively studies in yeast and mammals, as it is the limiting step of the synthesis of cholesterol. In plants, it is known that HMGR is also the limiting step in the biosynthesis of isoprenoides of the MVA pathway. In the genome of Arabidopsis thaliana, there are two genes that encode three different isoforms of HMGR. The two isoforms encoded in HMG1 gene differ only in an N-terminal extra region of 50 amino acids, and they were named according to that: HMGR1S or short, and HMGR1L or long isoform. HMGR1S is accumulated specifically in vesicles associated with it along its network. These vesicles are specific of the cotyledons and have an spin-shaped morphology. Similar structures called ER-bodies, involved in defense and adaptation to the environment have been described. Colocalization experiments in planta have shown that ER-bodies contain HMGR. Our results suggest that a very well-known metabolic protein, has a parallel function in the structure of the ER, important for the response to stress, without discarding that at the same time HMGR can produce an specific environment by recruiting other metabolic enzymes that lead to specific types of isoprenoid compounds.

Pour les technologies avancées, la lithographie optique par immersion utilisant des sources 193nm atteint ses limites en termes de résolutions. Les nouvelles techniques de lithographie telles que l’Extrême UV ou l’écriture à faisceaux multiples n’étant pas encore au point d’un point de vue industriel, un ensemble de techniques d’améliorations de la résolution (RET) en évolution constante permet de continuer à travailler avec les équipements à immersion. C’est dans ce contexte que s’inscrit cette thèse en se focalisant sur un des éléments principaux : le réticule. La première partie regroupe l’état de l’art de la photolithographie optique et des techniques d’amélioration de la résolution, ainsi qu’un ensemble de notions utile à la compréhension des parties B et C. La partie B concerne la réduction des effets de focalisation, plus connu sous l’appellation anglaise ‘’Best focus shift mitigation’’, observés sur des niveaux denses de type ‘’Metal’’ pour les technologies avancées. Cette partie permet de comprendre l’influence des organes physiques sur le trajet optique et propose comme solution au Best focus Shift un changement de réticule, validé d’abord via simulation puis par voie expérimentale sur plaquette. La partie C de ce manuscrit présente la prise en compte des effets inhérents à la fabrication des réticules dans l’étape de correction des effets de proximité optique, de la description des effets impliqués à la calibration et l’utilisation d’un modèle dédié. / For advanced technologies nodes, immersion optical lithography using 193nm sources reaches its limits in terms of resolutions. Since new lithography techniques such as Extreme UV or multi-beam writing are not yet ready from an industrial point of view, a continuous evolving set of tools known as Resolution Enhancement Technics (RET) allows to continue working with immersion equipment, pushing the resolution limits as much as possible. With the increasing design complexity, this task is more and more challenging. Within this frame this dissertation is addressed to improve the lithographic process variability by focusing on one of the main elements: the reticles.The first part brings together the state of the art of optical photolithography and resolution improvement techniques, as well as a set of concepts useful for parts B and C understanding. Part B deals with the reduction of focusing effects, better known as "Best focus shift mitigation", observed on dense levels such as "Metal" for advanced technologies. This part helps to understand the influence of the physical organs on the optical path and proposes as a solution to the Best focus Shift a reticle change, firstly validated via simulation and then experimentally at wafer level. Part C presents how the inherent effects of reticle fabrication can be taken into account in the Optical Proximity effects Corrections steps, from the description of the effects involved to the calibration and the use of a dedicated mask model