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Orientador: Patrícia Monteiro Seraphim / Banca: Ubiratan Fabres Machado / Banca: Ercy Mara Cipulo Ramos / Resumo: O tabagismo altera o metabolismo celular em vários aspectos e evidências apontam que este pode desencadear um quadro de resistência à insulina e, em longo prazo, Diabetes tipo 2. Dentre as alterações metabólicas mais importantes associadas à resistência à insulina, encontra-se a alteração na quantidade de transportador de glicose GLUT4 disponível na membrana plasmática de tecido muscular e tecido adiposo. No entanto, a atividade física aparece como um dos fatores que poderia modificar o risco dos indivíduos desenvolverem resistência insulínica e/ou diabetes, uma vez que pode aumentar a expressão da proteína e do RNAm do transportador de glicose GLUT4, estimulando o transporte de glicose por uma via independente da via de sinalização da insulina. Dentro deste contexto, este trabalho teve por objetivo avaliar o efeito do tabagismo e de atividade física moderada associada sobre a sensibilidade à insulina em músculos de ratos, através da quantificação de proteína e do RNAm do transportador de glicose GLUT4. Para a realização deste estudo foram utilizados ratos Wistar, divididos em 4 grupos: (CS) grupo controle, (CE) controle exercitado, (FS) fumante sedentário e (FE) fumante submetido a exercício físico. Os grupos FS e FE foram submetidos à combustão dee4 cigarros/vez, 30 minutos, 2x/dia, durante 60 dias. Os grupos CE e FE executaram protocolo de exercício em esteira rolante, 60 dias, 60 minutos por sessão... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Cigarette smoking changes the cellular metabolism in many aspects and evidences suggest that it is related to insulin resistance and type 2 diabetes. Within the metabolic alterations associated to insulin resistance we can mention disturbs on GLUT4 content in plasma membrane of muscle e adipose tissue. However, physical activity appears as a factor that could modify the risk for these pathologies, increasing GLUT4 expression and stimulating glucose transport, in an independent-pathway of insulin signaling. In this context, this study aimed to evaluate the effect of smoking and moderated physical activity on insulin sensitivity in muscle of rats, by quantifying GLUT4 protein and mRNA. For this study, it was used Wistar rats divided into 4 groups: control (CS), control submitted to an exercise protocol (CE), sedentary smoker (FS) and smoker submitted to an exercise protocol (FE). The FS and FE groups were submitted to cigarette smoke exposition, 4 cigarettes/30 min./twice a day for 60 days. Groups CE and FE performed running on a treadmill for 60 days during 60 minutes per session... (Complete abstract click electronic access below) / Mestre

Transmissivity (T) and Hydraulic apertures are often calculated from hydraulic test data obtained in fractured rock using analytical solutions such as the Thiem and cubic law equations developed for flow through unconsolidated porous media. These analytical solutions use a variety of simplifying assumptions, which are often violated due to the complex nature of flow through fractured rock systems which introduces error into the calculated hydraulic apertures. A 3-D discrete fracture network numerical model (SMOKER) for flow in dual-permeability media was used to simulate constant-head straddle packer tests to assess the errors in fracture characterization that result from deviations from the Thiem and cubic law assumptions caused by permeable rock matrix, variable aperture fractures, and complex flow patterns. The simulations indicate that SMOKER offers potential as a useful tool for representing non-ideal scenarios of rock and fracture network characteristics to assist in estimates and error analysis in T values and resultant errors in hydraulic aperture. / NSERC: Natural Sciences and Engineering Research Council of Canada

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Made available in DSpace on 2014-06-11T19:22:50Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-12-10Bitstream added on 2014-06-13T20:49:22Z : No. of bitstreams: 1 silva_pe_me_prud.pdf: 747809 bytes, checksum: dc9c919c8866b8929f30a2b3dbe33ab8 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O tabagismo altera o metabolismo celular em vários aspectos e evidências apontam que este pode desencadear um quadro de resistência à insulina e, em longo prazo, Diabetes tipo 2. Dentre as alterações metabólicas mais importantes associadas à resistência à insulina, encontra-se a alteração na quantidade de transportador de glicose GLUT4 disponível na membrana plasmática de tecido muscular e tecido adiposo. No entanto, a atividade física aparece como um dos fatores que poderia modificar o risco dos indivíduos desenvolverem resistência insulínica e/ou diabetes, uma vez que pode aumentar a expressão da proteína e do RNAm do transportador de glicose GLUT4, estimulando o transporte de glicose por uma via independente da via de sinalização da insulina. Dentro deste contexto, este trabalho teve por objetivo avaliar o efeito do tabagismo e de atividade física moderada associada sobre a sensibilidade à insulina em músculos de ratos, através da quantificação de proteína e do RNAm do transportador de glicose GLUT4. Para a realização deste estudo foram utilizados ratos Wistar, divididos em 4 grupos: (CS) grupo controle, (CE) controle exercitado, (FS) fumante sedentário e (FE) fumante submetido a exercício físico. Os grupos FS e FE foram submetidos à combustão dee4 cigarros/vez, 30 minutos, 2x/dia, durante 60 dias. Os grupos CE e FE executaram protocolo de exercício em esteira rolante, 60 dias, 60 minutos por sessão... / Cigarette smoking changes the cellular metabolism in many aspects and evidences suggest that it is related to insulin resistance and type 2 diabetes. Within the metabolic alterations associated to insulin resistance we can mention disturbs on GLUT4 content in plasma membrane of muscle e adipose tissue. However, physical activity appears as a factor that could modify the risk for these pathologies, increasing GLUT4 expression and stimulating glucose transport, in an independent-pathway of insulin signaling. In this context, this study aimed to evaluate the effect of smoking and moderated physical activity on insulin sensitivity in muscle of rats, by quantifying GLUT4 protein and mRNA. For this study, it was used Wistar rats divided into 4 groups: control (CS), control submitted to an exercise protocol (CE), sedentary smoker (FS) and smoker submitted to an exercise protocol (FE). The FS and FE groups were submitted to cigarette smoke exposition, 4 cigarettes/30 min./twice a day for 60 days. Groups CE and FE performed running on a treadmill for 60 days during 60 minutes per session... (Complete abstract click electronic access below)

In the United States, 19.3% of adults use some form of tobacco. Nicotine is a compound that is present in tobacco. Nicotine also has been detected in the calculus of teeth of archaeological specimens. The teeth are often well-preserved in unidentified human remains and are resilient in terms of damage from physical or chemical degradation. Dental plaque and calculus form on teeth and can entrap many chemical traces of compounds to which teeth are exposed. Many studies have examined the calculus microscopically and chemically using various techniques to establish patterns in diet, behavior, and health. Forensic odontologists can assist in the identification of individuals using dental records, but some individuals may not have recent or relevant records. In addition, some skeletal remains might only include a partial mandible or maxillae or may consist of only disarticulated teeth. However, given their representation in the anthropological record and the persistence of dental calculus on teeth postmortem, analyzing teeth for behavioral indicators can provide anthropologists with significant information to assist with identifying an individual. For example, detecting the presence of nicotine from teeth can provide information about tobacco use habits of an individual. In this study, the hypothesis was tested whether nicotine can be detected from teeth. It was also hypothesized that different behaviors of use would yield different quantities of nicotine in calculus, and that some nicotine in lower but detectable quantities may still be present from the teeth of non-users. Eighty-two teeth from the Boston University Goldman School of Dentistry were collected from tobacco users and non-users, which were determined by anonymous survey. All teeth were analyzed using gas chromatography mass spectrometry. Three types of sample extraction were tested. Solid-phase microextraction (SPME) was used with two subgroups of the overall sample. For Sample Groups A (n=41) and B (n=18), teeth were heated at 80ºC for an hour in a 20 mL SPME vial. An 85 μm polyacrylate SPME fiber was exposed to the headspace of the vials for 15 minutes for teeth in group A and 30 minutes for teeth in group B. For sample group C (n=24), teeth were sonicated in 5 mL ethanol for 30 minutes. After sonication, the ethanol was pipetted into autosampler GC vials. All samples were analyzed on an Agilent Technologies 7890A Gas Chromatography system connected to and Agilent Technologies 5975C inert XL EI/CI Mass Spectrometer and data produced were analyzed using Agilent ChemStation Software. Gas chromatography –mass spectrometry parameters were consistent across all samples, with a solvent delay for the group C samples. Results indicated that while SPME is sensitive enough to detect spiked nicotine from prepared samples, the extraction method did not show any significant data which would identify users. For the samples which were extracted by sonication in methanol, there was an increased likelihood that teeth belonging to a user had a positive identification for nicotine. Of the sonicated samples, 63.6% of teeth from tobacco users showed a positive hit after sonication, while none of the non-user teeth had positive nicotine hits. However, the amount of nicotine detected from each sample does not necessarily reflect tobacco user behavior such as daily frequency, years of use, or type of tobacco.

Nikotin gilt als die Abhängigkeit verursachende Komponente im Zigarettenrauch. Zudem hat Nikotin einen Einfluss auf die Ausbildung von lang anhaltenden kortikalen Erregbarkeitsveränderungen. Diese als neuroplastisch bezeichneten Veränderungen gelten als neurophysiologische Grundlage von Lern- und Gedächtnisprozessen. Die kognitiven Fähigkeiten sind bei Rauchern im Nikotinentzug reduziert und bessern sich erst nach Nikotingabe wieder. Auch Nichtraucher zeigen verbesserte kognitive Leistungen nach Nikotingabe. Im Rahmen dieser Arbeit sollte untersucht werden, in welchem Maße nikotinerge Acetylcholin-Rezeptoren bei der Induktion von inhibitorischen kortikalen Erregbarkeitsveränderungen im menschlichen Gehirn eine Rolle spielen. Daher führten wir Versuche mit dem für diese Rezeptoren spezifischen Liganden Nikotin durch. Wir untersuchten den Einfluss von schnell anflutendem Nikotin in Form von Nasenspray und eines kontinuierlich hohen Nikotinspiegels in Form eines Nikotinpflasters auf inhibitorische kortikale Erregbarkeitsveränderungen bei Rauchern und Nichtrauchern. Für die Auslösung fokaler inhibitorischer Erregbarkeitsveränderungen verwendeten wir die gepaarte assoziative Stimulation (PAS). Mittels transkranieller Magnetstimulation wurden die kortikalen Exzitabilitätsveränderungen über die Änderung der MEP-Amplituden im Musculus abductor digiti minimi erfasst. Ohne Nikotin hatten sowohl Nichtraucher als auch Raucher die Fähigkeit zur Ausbildung von inhibitorischen kortikalen Erregbarkeitsveränderungen, wobei diese bei Rauchern im Nikotinentzug deutlich schlechter ausgeprägt waren als bei Nichtrauchern. Bei Nichtrauchern wurden die inhibitorischen Nacheffekte der PAS durch Nikotin aufgehoben bzw. vermindert, während sie bei Rauchern initial kürzer anhielten, später jedoch erneut auftraten. Unsere Ergebnisse zeigen, dass Nikotin eine wichtige Rolle bei der Ausbildung von inhibitorischen kortikalen Erregbarkeitsveränderungen spielt. Da diese als neuroplastisch bezeichneten Veränderungen als neurophysiologisches Korrelat für Lernvorgänge und Gedächtnis angesehen werden, lässt sich ein hierdurch vermittelter Einfluss von Nikotinabhängigkeit und Nikotinentzug auf kognitive Prozesse annehmen. Zudem nimmt Nikotin einen bedeutsamen Einfluss auf die durch zerebrale Stimulationsprotokolle wie die PAS ausgelösten Effekte.

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Cette thèse présente une étude détaillée de la composition des fluides de haute température du champ hydrothermal de Lucky Strike (37°N, dorsale médio atlantique) s'appuyant sur 3 campagnes d'échantillonnage réalisées dans le cadre de l'observatoire fond de mer EMSO-Açores. Ce champ hydrothermal s'est développé autour d'un lac de lave fossile bordé au Nord-Ouest, Nord Est et Sud Est par des cônes volcaniques plus anciens. En 2013, la découverte du site hydrothermal de Capelinhos à l'Est, et présentant des compositions de fluides inédites à Lucky Strike (concentration faible en Cl et forte en Fe et Mn), nous permet de proposer un nouveau modèle de circulation hydrothermale basé sur l'application de géothermobaromètres (Si ; Si-Cl ; Fe-Mn) chimiques sur 13 évents hydrothermaux. Nous avons défini 5 groupes de sites selon leur chlorinité et leur position par rapport au lac de lave. Les fluides de Capelinhos, dominés par la phase vapeur, sont rapidement extraits de la zone de séparation de phase (estimée à 2600 m sous le plancher océanique). Les fluides à proximité du lac de lave, avec des chlorinités variables, suggèrent un rééquilibrage à des pressions et températures plus faibles qu'à Capelinhos, cohérent avec des processus de refroidissement conductif et/ou d'entrainement de saumures prenant place lors de la remontée des fluides jusqu'à la base de la couche 2A. La fluctuation de la chlorinité témoigne de la variabilité du temps de résidence du fluide dans la zone de remontée, et ses relations avec les caractéristiques physiques de la croûte océanique. Nous avons évalué la variabilité temporelle de la composition des fluides collectés au cours des campagnes effectuées entre 2009 et 2015. Deux échelles de temps sont mises en évidence. (1) l'échelle de l'échantillonnage, i.e. de l'heure, répond à des phénomènes de subsurface, et révèle qu'un fluide hydrothermal refroidi conductivement (T<150°C) est stocké dans la roche poreuse entourant le site de décharge. (2) l'échelle de temps pluri-annuelle montre une fluctuation des conditions de P et T apparentes de la zone de séparation de phase et du degré d'altération du substratum dans la zone de réaction. Les variations intersites du rapport Ca/Na (indicateur du degré d'albitisation) sont dues à la séparation de phase, à l'exception des sites du Sud-Est du lac de lave qui indiquent un degré d'altération plus élevé. La concentration en Li et sa composition isotopique indiquent que le basalte du substratum est relativement frais avec des rapports W/R proches de 1 pour tous les groupes, avec des d7Li du fluide identiques au substratum. Pour le Sr nous calculons des rapports W/R plus élevés, autour de 7-8, qui sont dus au Sr de l'eau de mer initiale qui est partiellement stocké et à la formation de minéraux secondaires(l'albite et l'anhydrite) lors des interactions eau-roche dans le faciès schiste vert. La faible teneur en métaux des fluides situés autour du lac de lave est probablement due à un piégeage en subsurface, équivalent à ~65% du Fe mobilisé dans la zone de réaction (basé sur les teneurs des fluides de Capelinhos). La variabilité de chlorinité des fluides de Lucky Strike offre l'opportunité d'étudier le comportement des terres rares à l'échelle d'un site hydrothermal. Ainsi, nous montrons l'effet de la séparation de phase sur les terres rares légères et lourdes ainsi que le lien entre l'Eu et le cycle géochimique du Sr. Les terres rares dissoutes dans le panache hydrothermal montrent une perte au cours du mélange ainsi que des phénomènes de redissolution visible via la signature isotopique en Nd. Cette modification des compositions isotopiques en Nd de l'eau de mer profonde est similaire au " boundary exchange " observé aux interfaces océan-plateforme continentale. Au vue de la répartition des champs hydrothermaux sur les dorsales océaniques, ce phénomène pourrait avoir un impact sur le bilan océanique du Nd et donner lieu à un phénomène de " ridge exchange ". / This thesis present a detailed study of the composition of high temperature fluid from the Lucky Strike hydrothermal field (37°N, Mid Ocean Ridge) collected during three sampling campaigns within the framework of the deep sea observatory EMSO-Azores. The hydrothermal field has developped around a fossil lava lake framed by three ancient volcanic cones. In 2013, the discovery of a new active site to the East of the system, and presenting an unprecedented fluid composition at Lucky Strike (low Cl concentration and high Fe and Mn concentration), lead to a new model of hydrothermal circulation based on chemical geothermobarometer (Si; Si-Cl) and geothermometer (Fe-Mn) applied to 13 venting sites. We defined 5 groups of sites based on their chlorinity and location around the lava lake. It appears that vapor-dominated Capelinhos fluids were extracted relatively fast from the phase separation zone (estimated at ~2600mbsf). Nevertheless, fluids in the vicinity of the lava lake, both vapor and brine dominated, display P and T conditions of equilibration lower than for Capelinhos fluids. This highlights on-going equilibration process through conductive cooling and/or brine entrainment in the upflow zone up to the layer 2A of the oceanic crust. Chlorinity variations highlight the varying residence time in the upflow of the fluids between vents which depends on physical characteristics of the crust. We studied the temporal variability of fluid composition collected between 2009 and 2015. Two time scales have been evidenced. The first is the sampling scale, i.e. ~1h, and corresponds to subsurface processes indicating that a hydrothermal fluid, conductively cooled (T<150°C), was stored in the porous substratum close to the discharge. The second is at the scale of the year. It shows fluctuations of P and T conditions in the phase separation and different degree of alteration of the substratum in the reaction zone. Intersites variations of Ca/Na ratios (proxies for albitisation) are related to phase separation expected the South Eastern sites that display a more altered substratum. To avoid this issue, we use Li and Sr isotopes which are not affected phase separation. Li concentration and isotopic composition indicates that basalt substratum is relatively fresh with W/R ratio close to 1 calculated for all groups with d7Li of fluid equivalent to substratum. Sr concentration and isotopic composition suggest higher W/R ratio (~7-8) because of seawater Sr partially removed in the recharge. Moreover, other parameters are at play such as secondary mineral formation (albite, anhydrite) during water rock interaction in the greenschist facies. Because the basalt is relatively fresh, the low metal content in the fluid around the lava lake is due to storage, in the subsurface, of approximately ~60-70% of Fe that is mobilized in the reaction zone compared to Fe-Mn rich Capelinhos fluids. Furthermore, the Cl variability from the fluids at Lucky Strike brings a unique opportunity to study the REE distribution from the reaction zone to the discharge into the deep ocean. We show that the LREE are preferentially concentrated into the brine phase. Furthermore, the Eu is linked to the Sr geochemical cycle. Dissolved REE from buoyant plume fluids highlight a scavenging effect. The Nd isotopic compositions indicate redissolution process. This Nd isotopes modification of the deep seawater is similar to the process of "boundary exchange" that occurs at the ocean/continents interface. Considering the global distribution of submarine hydrothermalism, the Nd modification at the ridge could have an impact on the global Nd cycle in the oceans and act as a "ridge exchange".

In order to explain the observed time-dependent salinity variations in seafloor hydrothermal vent fluids, quasi-numerical and fully numerical fluid flow models of the NaCl-H2O system are constructed. For the quasi-numerical model, a simplified treatment of phase separation of seawater near an igneous dike is employed to obtain rough estimates of the thickness and duration of the two-phase zone, the amount of brine formed, and its distribution in the subsurface. For the fully numerical model, the equations governing fluid flow, the thermodynamic relations between various quantities employed, and the coupling of these elements together in a time marching scheme is discussed. The fully numerical model is benchmarked against previously published heat pipe and Elder problem simulation results, and is shown to be largely in agreement with those results. A number of simulation results are presented in the context of two-phase flow and phase separation within the framework of the single pass model. It is found that a quasi-stable two-phase (liquid + vapor) zone at depth below the hydrothermal discharge outlet gives rise to vent fluid with lower than normal seawater salinity. Additionally, it is shown that increasing the spatial extent of the two-phase zone can lower vent fluid salinity. The numerical approach used in this thesis is able to generate salinity patterns predicted by a widely held conceptual model of vent fluid salinity variation, and may be able to explain the vent fluid salinities and temperatures found at the Main Endeavour Vent Field on the Juan de Fuca Ridge, as this approach is able to produce simulated vent fluid salinities that match observed values from the Endeavour Field vents Dante and Hulk.