Made available in DSpace on 2016-06-02T19:22:51Z (GMT). No. of bitstreams: 1 2475.pdf: 1572607 bytes, checksum: 64043b30c1df210d393c4540c2d88933 (MD5) Previous issue date: 2009-05-29 / Universidade Federal de Minas Gerais / The locus coeruleus (LC) has been suggested as a CO2 chemoreceptor site in mammals. Substance P (SP) has been used as a marker of respiratory neurons and it plays an important role in compensatory responses to hypercapnia in several sites of the central nervous system. Neurokinin-1 (NK-1) receptor immunoreactive (NK1Rir) neurons and processes are widely distributed within the LC. Thus, the present study assessed the role of NK-1 receptors in the LC in the cardiorespiratory and thermal responses to hypercapnia. To this end, substance P-saporin conjugate (SPSAP; 2μM) was injected in the LC to kill NK1R-ir neurons, or IgG-SAP as a control in male Wistar rats. The animals that the drug reached the fourth ventricle (4ºV) were considered as a 4ºV group. Pulmonary ventilation (VE, body plethysmograph), mean arterial pressure (MAP), heart rate (HR) and body core temperature were measured followed by 60 min of hypercapnic exposure (7% CO2). To verify the correct placement and effectiveness of the chemical lesions, immunohistochemistry for NK1R was performed. In addition, tyrosine hydroxylase (TH) immunoreactivity was performed to verify if noradrenergic neurons were eliminated. Fluoro-Jade technique was used to evaluate neuronal degeneration. A reduced NK1R (72% of reduction) and TH immunoreactivity (66% of reduction) was observed seven days after the injections of SP-SAP in the LC and an intense Fluoro-Jade staining, showing the effectiveness of the lesion. Focal lesions of NK1R-ir did not affect basal ventilation in the SP-SAP in LC and SP-SAP in 4ºV groups. Hypercapnia caused an increase in pulmonary ventilation in all groups, which was a result of increases in respiratory frequency (fR) and tidal volume (VT), SP-SAP treatment in the LC and in the fourth ventricle attenuated the hypercapnic ventilatory response (30% and 20%, respectivally), due to a reduction in the VT. SP-SAP in the LC and SP SAP in the 4ºV 11 lesion did not affect MAP, but caused an increase in HR in both groups. The results suggest that NK1R-ir neurons in the LC modulate hypercapnic ventilatory response but play no role in breathing control under resting conditions. Additionally, NK1R-ir neurons seem to play no role in body temperature and MAP regulation in resting conditions and during hypercapnia, but modulate HR during CO2 exposure. This modulation may be due to a change in the noradrenaline release. / O locus coeruleus (LC) é considerado uma região quimiorreceptora a CO2/pH em mamíferos. A substância P (SP) tem sido usada como marcador de neurônios respiratórios, pois possui importante função nas respostas compensatórias a hipercapnia em muitas áreas do sistema nervoso central. Neurônios e processos imunorreativos a receptores neurocinina 1 (NK-1) estão amplamente distribuídos dentro do LC. Portanto, o presente estudo teve por objetivo avaliar a participação de receptores NK-1 no LC nas respostas cardiorrespiratórias e termorreguladoras à hipercapnia. Para este fim, foi injetado o conjugado SP-Saporina (SP-SAP; 2μM) no LC de ratos Wistar para lesar neurônios que expressam esses receptores, ou IgGSAP como controle. Os animais em que as injeções atingiram o quarto ventrículo (4ºV) foram considerados como grupo 4ºV. A ventilação pulmonar (VE, pletismografia de corpo inteiro), pressão arterial média (PAM), freqüência cardíaca (FC) e temperatura corporal (Tc) foram medidas por 60 min de exposição à hipercapnia (7% CO2). Para verificar a correta localização e efetividade da lesão química realizou-se a imunohistoquímica para receptores NK-1. Além disso, imunohistoquímica para tirosina hidroxilase (TH) foi realizada para averigüar se neurônios noradrenérgicos foram lesados. A técnica de Fluoro-Jade foi também utilizada para avaliar a neurodegeneração. Observou-se a redução da imunorreatividade para receptores NK-1 (72% de lesão dos neurônios) e redução da imunorreatividade para neurônios noradrenérgicos (66% dos neurônios noradrenérgicos) sete dias após injeções de SP-SAP no LC e intensa marcação na técnica de Fluoro-Jade mostrando a efetividade da lesão. Lesões seletivas de neurônios que expressam receptores NK-1 no LC não afetaram a ventilação basal, o mesmo foi observado com os animais em que a injeção atingiu o 4ºV. A hipercapnia causou aumento da ventilação pulmonar 9 em todos os grupos decorrente do aumento da freqüência respiratória (fR) e volume corrente (VC). Entretanto, o tratamento com SP-SAP no LC e no 4ºV promoveu atenuação da resposta ventilatória (30% e 20%, respectivamente), devido à diminuição do VC. A lesão com SP-SAP no LC e no 4ºV não afetou a PAM, entretanto promoveu aumento na FC em ambos grupos. Os resultados sugerem que os neurônios que expressam receptores NK-1 no LC modulam a resposta ventilatória à hipercapnia, porém não possuem papel tônico na ventilação em condições basais. Além disso, esses neurônios não participam da regulação da temperatura e da PAM em normocapnia e hipercapnia, mas modulam FC durante exposição ao CO2. Essa modulação pode ser devida a alteração na liberação de noradrenalina.

abstract: A variety of studies have shown that the tendency toward nicotine dependence has a genetic component. The work described in this thesis addresses three separate questions: i) are there unidentified SNPs in the nicotinic receptors or other genes that contribute to the risk for nicotine dependence; ii) is there evidence of ongoing selection at nicotinic receptor loci; and, iii) since nicotine dependence is unlikely to be the phenotype undergoing selection, is a positive effect on memory or cognition the selected phenotype. I first undertook a genome –wide association scan of imputed data using samples from the Collaborative Study of the Genetics of Nicotine Dependence (COGEND). A novel association was found between nicotine dependence and SNPs at 13q31. The genes at this newly associated locus on chromosome 13 encode a group of micro-RNAs and a member of the glypican gene family. These are among the first findings to implicate a non-candidate gene in risk for nicotine dependence. I applied several complimentary methods to sequence data from the 1000 Genomes Project to test for evidence of selection at the nicotinic receptor loci. I found strong evidence for selection for alleles in the nicotinic receptor cluster on chromosome 8 that confer risk of nicotine dependence. I then used the dataset from the Collaborative Studies on the Genetics of Alcoholism (COGA) and looked for an association between neuropsychological phenotypes and SNPs conferring risk of nicotine dependence. One SNP passed multiple test correction for association with WAIS digit symbol score. This SNP is not itself associated with nicotine dependence but is in reasonable (r 2 = 0.75) LD with SNPs that are associated with nicotine dependence. These data suggest at best, a weak correlation between nicotine dependence and any of the tested cognitive phenotypes. Given the reproducible finding of an inverse relationship between SNPs associated with risk for nicotine dependence and cocaine dependence, I hypothesize that the apparently detrimental phenotype of nicotine dependence may confer decreased risk for cocaine dependence. As cocaine use impairs the positive rewards associated with social interactions, reducing the risk of cocaine addiction may be beneficial to both the individual and the group. / Dissertation/Thesis / Ph.D. Anthropology 2014

L'exocytose régulée, est un processus qui permet la communication entre les cellules à travers la sécrétion des hormones et des neurotransmetteurs. Dans les neurones et les cellules neuroendocrines, l'exocytose est strictement contrôlée par des signaux extracellulaires tels que le potentiel trans-membranaire et la fixation des ligands sur des récepteurs. Des progrès substantiels ont été effectués afin de comprendre le mécanisme moléculaire de l'exocytose. Les composants majeurs de la machinerie de sécrétion ont été dévoilés. Maintenant, la question qui émerge concerne le rôle de la plateforme de protéines qui semble avoir une action coordonnée entre chaque protéine. Dans le cas de la famille des annexines, qui est bien connue pour son action dans l'exocytose, leurs modes d'interactions séquentielles ou concertées avec d'autres protéines ainsi que leurs effets régulateurs sur l'exocytose ne sont pas encore bien établis. Des résultats précédents indiquent que l'Annexine A6 (AnxA6) affecte l'homéostasie du calcium et la sécrétion de la dopamine à partir des cellules PC12, utilisées comme un modèle cellulaire de neurosécrétion (Podszywalow Bartnicka et al., 2010). Afin de déterminer l'effet inhibiteur de l'AnxA6 sur l'exocytose de la dopamine, nous cherchons des partenaires moléculaires de l'AnxA6 dans les cellules PC12. Nous faisons l'hypothèse que l'AnxA6 interagit avec la PLD1, une enzyme active dans l'étape de la fusion des vésicules avec la membrane plasmique. En utilisant la microscopie confocale et la microscopie à onde évanescente, nous avons trouvé que l'isoforme 1 de l'AnxA6 et la PLD1 sont tous les deux recrutés sur la surface des vésicules au cours de la stimulation des cellules PC12. AnxA6 inhibait l'activité de la PLD comme indiqué par notre méthode d'analyse enzymatique au moyen de la spectroscopie infrarouge. En conclusion, nous proposons que l'AnxA6 n'est pas seulement impliquée dans la réorganisation des membranes par ses capacités à se lier avec des phospholipides négativement chargés et avec le cholestérol, mais elle influence également l'activité de la PLD1, changeant la composition lipidique des membranes / The regulated exocytosis is a key process allowing cell-cell communication through the release of hormone and neurotransmitters. In neurons and neuroendocrine cells, it is strictly controlled by extracellular signal such as transmembrane potential and ligand bindings to receptors. Substantial progress has been made to understand the molecular mechanism of exocytosis. Major components of secretory machinery have been brought to light. Now the emergent question concerns the role of scaffolding proteins that are thought to coordinate the action of each other. In the case of annexin family well known to be involved in exocytosis, their modes of –sequential or concerted- interactions with other proteins, and their regulatory effects on exocytosis are not very well established. Previous findings indicated that Annexin A6 (AnxA6) affected calcium homeostasis and dopamine secretion from PC12 cells, used as cellular model of neurosecretion (Podszywalow-Bartnicka et al., 2010). To determine the inhibitory effect of AnxA6 on exocytosis of dopamine, we were looking for molecular partners of AnxA6 in PC12 cells. We hypothesized that AnxA6 interacts with phospholipase D1 (PLD1), an enzyme involved in the fusion step. By using confocal microscopy and total internal reflection fluorescence microscopy, we found that isoform 1 of AnxA6 and Phospholipase D1 are both recruited on the surface of vesicles upon stimulation of PC12 cells. AnxA6 inhibited phospholipase D activity as revealed by our enzymatic assay based on infrared spectroscopy. To conclude, we propose that AnxA6 is not only implicated in membrane organization by its capacity to bind to negative charged phospholipids and to cholesterol, but AnxA6 is also affecting PLD1 activity, changing membrane lipids composition

This thesis sets out to probe the complex artistic contacts between Italy and Cyprus in the visual arts during the High and Late Middle Ages. The Introduction provides a critical review of the subject. Chapter I maps out the various types of links (with respect to trade, religion, warfare, art, culture) between Italy and Cyprus in the thirteenth and fourteenth centuries. Chapters II and III examine the multifaceted artistic negotiations between southern Italy (mainly Apulia) and Cyprus in the thirteenth century, by closely examining a cluster of frescoes and panel paintings. Through a set of historical, cultural and artistic (stylistic and iconographic) approaches, these chapters aim to supersede the somewhat limited style-oriented analyses of previous contributions to this area of study. The hitherto unverified and convoluted relations between the two regions are revisited and affirmed within a new conceptual framework. Chapters IV and V investigate fourteenth-century cross-currents as seen in two cases that have formerly occupied a marginal position in discussions of intercultural exchanges between Italy and Cyprus. The first is the transplantation and manifestation of the cult of Saint Thomas Aquinas in Cyprus, and the second, the hybrid series of icons created by Italian painters working on the island. Both cases are appraised as a record of historical realities and not as the by-products of casual encounters. The thesis historicises these contacts and in doing so, contributes to a broader understanding of cultural transmission and convergence in the Medieval Mediterranean.

The Niemann-Pick type C (NPC) disease is a lysosomal lipid storage disorder caused by mutations in one of the two genes NPC1 or NPC2 encoding proteins of the late endosome/lysosome compartment (LE/LY). Defect in these proteins alters vesicular transport and leads to abnormal accumulation of cholesterol (Chol) in LE/LY. There are some lines of evidence suggesting that annexin A6 (AnxA6) participates in vesicular transport of Chol and may interact with membrane domains enriched in Chol and bind Chol. In this work we characterized the membrane microdomains resistant to Triton X-100, i.e., detergent-resistant membranes (DRMs) isolated from NPC patient-derived fibroblasts and from control cells. NPC cells contain a significantly higher amount of DRMs than the control cells that is consistent with the defect in Chol turnover in NPC cells. We also studied the mechanism of AnxA6 involvement in the NPC-induced changes in the membrane organization and showed that in the presence of calcium some AnxA6 molecules associate with the DRMs. This suggests that AnxA6 may play a role in the membrane lateral organization, contributing thus to the etiology of NPC disease. We then focused on the interaction of AnxA6-1 with Chol-rich membranes and on the involvement of its flexible region and VAAEIL sequence in these interactions. For this purpose, kinetics of the interfacial adsorption of human recombinant AnxA6 to Langmuir monolayers containing phosphatidylcholine, Chol and/or cholesteryl acetate were measured. Our data suggest that AnxA6 exhibits the highest affinity to Chol-containing monolayers and that the hydroxyl group of Chol plays a pivotal role in the AnxA6-lipid interactions in vitro.

This thesis examines the role of the former national screen agency in Scotland, which was in charge of distributing public funds for screen activity between 1997 and 2010. It examines how external factors such as cultural policy and internal factors such as individual approaches to film funding, affected the agency's perception and remit. The study draws on the institutional logics perspective (Thornton et al., 2012) to frame the interplay of two competing imperatives, one commercial, one creative, affecting the creative industries in Scotland and Scottish Screen's activities more specifically. However, it goes beyond this duality by examining more nuanced factors which significantly affected the organisation's trajectory and remit. Taking into account the predominant logic(s) throughout Scottish Screen's history and focusing on organisational responses during moments of transition or conflict, I use the analytical framework developed by Boltanski and Thévenot in On Justification (2006) to examine criticisms, justifications, and attempts at compromising expressed through official and non-official channels. The thesis outlines how opinions and decisions stemming from disparate views of what is “worthy” affected the agency's activity and funding decisions, as well as the dialogue with its stakeholders. The conclusions extracted from my findings inform existing literature on responses to plurality and challenge some claims made by institutional logic scholars: the first conclusion is that lack of conflict between logics does not necessarily translate into lack organisational conflict, as the latter often derives from different orders of worth which override the commercial-creative logic divide and are incompatible amongst themselves. The second conclusion, related to the first one, is that stability may be enhanced (at least temporarily) in a professional environment dominated by a plurality of logics as long as there is compatibility amongst the orders of worth set forth in pursuit of organisational goals. A third conclusion is related to the examination of some contributions to the orders of worth perspective and the study of plurality and instability in organisational practices, notably Boltanski and Chiapello's (2007) depiction of a seventh world of worth called the ‘projective city' (underpinned by the higher value of activity aimed at creating or maintaining ever-changing networks), and David Stark's (2009) study of plurality and ambiguity management in organisations. My findings suggest that organisational models based on pervasive, horizontal networks capable of transgressing traditional hierarchical structures were never fully deployed in Scottish Screen - traces of these practices are identified, but, overall, actors defended more traditional organisational scripts.

'William Cecil and the British succession crisis of the 1560s' reconsiders the nature of the early Elizabethan polity and Cecil's place in it. Conventional historiography maintains that as principal secretary Cecil was a moderate, cautious, and religiously neutral politician, content to follow Elizabeth I's direction in policy. More recently, Professors Patrick Collinson and John Guy have challenged this interpretation of the Elizabethan polity. Based on a thorough survey of the archives, my thesis explores Cecil's political creed in the 1560s. Three years of research have helped to paint a radically different picture of Cecil to the one traditionally represented: he was a councillor prepared to redefine his relationship with a monarch who refused to abide by the rules of monarchy and select a successor. The eight chapters of the thesis blend two complementary themes. First, that Elizabethan in the 1560s experienced a British succession crisis and not, as Professor Collinson has maintained, an English domestic succession crisis. And second, that the political situation in Britain and Europe - the determination of the continental catholic powers to use Mary Stuart's claim to the English throne as a weapon against protestant England - had a profound impact on the mentality of protestant Englishmen and debate in England. It persuaded Cecil to press for a pre-emptive strike against the French in Scotland (chapter two), which he defended by appealing to the feudal-imperial power of the English monarch; he used the same argument to justify the 'first trial' of Mary Stuart in 1568 (chapter seven). In this British context, Elizabeth's refusal to secure England's future led to parliamentary action in 1563 and a Cecil plan for interregnum by privy council in the event of Elizabeth's death, twenty-two years before its re-emergence in 1585 (chapter four). The régime could not find a diplomatic solution to the marriage between Mary and Lord Darnley in 1565 (chapter five): parliament debated the succession in 1566 and Cecil disobeyed the queen by pressing for a settlement (chapter six). Cecil's approach to the crisis was innovative, and his political creed is profoundly important to any assessment of politics in Elizabeth I's reign.

In this thesis I test the modified Newtonian dynamics as an alternative to the cold dark matter hypothesis. In the Milky Way, I show that the dynamics of the dwarf galaxies are well described by the paradigm and I confirm its distant low surface brightness globular clusters provide a strong test, for which I make predictions. Through analysis of a sample of 26 X-ray bright galaxy groups and clusters I demonstrate that the three active neutrinos and their anti-particles are insufficient to reconcile modified Newtonian dynamics with the observed temperatures of the X-ray emitting gas, nor with weak-lensing measurements, in particular for the bullet cluster. To this end, I propose an 11eV sterile neutrino to serendipitously resolve the residual mass problem in X-ray bright groups and clusters, as well as matching the angular power spectrum of the Cosmic Microwave Background. With this in mind, I show that the large collision velocity of the bullet cluster and the high number of colliding clusters is more naturally reproduced in MOND than in standard dynamics.

“Race in a Godless World” examines the racial thought of atheists in Britain and the United States from about 1850 to 1914. While there have been no comprehensive studies of atheists' views on race, there is a trend in the historiography on racial thought, which I have described as the “Race-Secularization Thesis,” that suggests a link between the secularization in the eighteenth and nineteenth centuries and an increase in nineteenth-century racialism – that is, racial essentialism and determinism – as well as resulting racial prejudice and discrimination. Through a study of both leading and lesser-known atheists and freethinkers, I argue that the “Race-Secularization Thesis” needs to be reconsidered. A simple link between secularization and racialism is misleading. This is not to suggest that the “Race-Secularization Thesis” contains no truth, only that secularization did not inevitably lead to racialism. This dissertation helps to tell a more complex and nuanced story about the relationship between atheism and racial thought. While in some cases, nineteenth-century atheists and freethinkers were among the leading exponents of racialist views, there is an alternative story in which the atheist worldview – through its emphasis on rationality and skepticism – provided the tools with which to critique ideas of racial prejudice, racial superiority, and even the concept of race itself.

Cette thèse vise à démontrer l’importance de la PI 3-kinase dans la régulation hormonale de la réabsorption rénale du sodium. Ce contrôle extrêmement précis, notamment par l’aldostérone, s’effectue au niveau du néphron distal. Nous avons utilisé comme modèle l’épithélium de cellules A6, dérivées du tubule distal de Xenopus Laevis. Le transport unidirectionnel de sodium s’effectue en deux étapes: depuis, l’entrée à partir du milieu luminal par des canaux sodiques épithéliaux (ENaCs) insérés dans la membrane apicale, jusqu’à la sortie vers le liquide extracellulaire par des pompes Na+/K+-ATPases, situées dans la membrane basolatérale. L’insuline augmente ce transport de sodium et la PI 3-kinase semble assurer un rôle-clef.<p>Nous avons étudié l’importance de chacun des 3-phosphoinositides produits par la PI 3-kinase, sur le transport du sodium en ajoutant au milieu cellulaire des formes «perméantes» de ces phospholipides. Parmi ceux-ci, le PIP3 et dans une moindre intensité le PI(3,4)P2 augmentent ce transport. En revanche, le PI3P, le PI(3,5)P2, ainsi que le PI(4,5)P2 n’ont pas d’effet sur lui. Nous avons démontré par la technique du Western blot que la 3-phosphatase PTEN est exprimée dans les cellules A6. Cette phosphatase déphosphoryle le PIP3 en PI(4,5)P2. Nous avons surexprimé PTEN dans les cellules A6. Ceci réduit l’augmentation du transport du sodium induite par l’insuline, ainsi que celle induite par addition de la forme «perméante» de PIP3. <p>Nous avons ensuite vérifié si d’autres agents qui activent la PI 3-kinase, stimulent également le transport de sodium à travers cet épithélium. A cette fin, nous avons d’abord vérifié que l’EGF et le peroxyde d’hydrogène, connus pour stimuler la PI 3-kinase dans d’autres systèmes, activent également cette enzyme dans les cellules A6. Tous deux augmentent ce transport. L’importance de l’augmentation induite par H2O2 est comparable à celle de l’insuline, tandis que l’effet de l’EGF est plus transitoire. Un dosage d’activité de la PI 3-kinase, nous a permis de démontrer que l’intensité de l’activation de la PI 3-kinase est corrélée avec l’amplitude de l’augmentation du transport du sodium. Par comparaison avec l’effet de l’insuline et de l’H2O2, l’EGF augmente faiblement l’activité de la PI 3-kinase et induit une faible augmentation du transport. <p>Nous avons également examiné si la voie des MAPK influence la stimulation du transport du sodium par ces différents agents. Cette voie ne semble pas impliquée dans l’effet de l’insuline ou du peroxyde d’hydrogène. Par contre, elle diminue la stimulation du transport de sodium par l’EGF. L’effet de l’EGF sur le transport semble résulter d’un compromis entre l’activation de la voie de la PI 3-kinase qui l’augmente et l’activation de la voie des MAPK qui le diminue.<p>En conclusion, une augmentation de PIP3, soit par addition de PIP3 exogène, soit par augmentation endogène sous l’effet de l’insuline ou d’autres agents stimulant la PI 3-kinase, augmente le transport du sodium tandis qu’une diminution de PIP3 endogène (par surexpression de PTEN) le diminue. L’importance de l’activation de la PI 3-kinase est quantitativement corrélée avec l’importance de l’augmentation du transport du sodium. La PI 3-kinase est donc un médiateur-clef de la régulation rénale de ce transport.<p> / Doctorat en sciences biomédicales / info:eu-repo/semantics/nonPublished