Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-10-04T11:07:31Z No. of bitstreams: 1 rodrigodasilvacerqueiro.pdf: 726774 bytes, checksum: 3ed9b91527aeb1c45e993b1ac8e0862d (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-10-04T15:58:09Z (GMT) No. of bitstreams: 1 rodrigodasilvacerqueiro.pdf: 726774 bytes, checksum: 3ed9b91527aeb1c45e993b1ac8e0862d (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-10-04T15:58:21Z (GMT) No. of bitstreams: 1 rodrigodasilvacerqueiro.pdf: 726774 bytes, checksum: 3ed9b91527aeb1c45e993b1ac8e0862d (MD5) / Made available in DSpace on 2016-10-04T15:58:21Z (GMT). No. of bitstreams: 1 rodrigodasilvacerqueiro.pdf: 726774 bytes, checksum: 3ed9b91527aeb1c45e993b1ac8e0862d (MD5) Previous issue date: 2010-07-20 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / O presente trabalho tenta, mesmo que de forma breve, uma análise do projeto literário de Luiz Ruffato, intitulado Inferno provisório. É nosso desejo uma ―crítica integradora‖, que una referências da história, sociologia e teoria literária na tentativa de elucidar alguns aspectos da ficção do escritor mineiro. O trabalho se divide em quatro capítulos. No primeiro, buscamos analisar os aspectos formais de Inferno provisório, como a filiação ou não dos livros que o compõem na categoria romance; a construção do narrador, pautada pela multiplicidade de vozes na construção das narrativas e as modulações da linguagem exercidas por Ruffato adotando o que chamaremos de ―escrita migrante‖, uma escrita que se pauta pela constante variação entre os registros formal e coloquial. Ainda no primeiro capítulo, buscaremos identificar já no título do projeto literário (a junção entre os termos ―inferno‖ e ―provisório‖) instrumentos para a interpretação e reflexão crítica acerca do mundo ficcional criado pelo autor, ao que chamaremos de ―realidade da ficção‖. Os três capítulos subsequentes compreenderão análises de seis histórias presentes em Inferno provisório, tentando refletir sobre a possibilidade de, nessas, haver a ocorrência de um desequilíbrio entre idealização e realização que compreende as trajetórias das personagens criadas pelo autor. Esse desequilíbrio agirá como principal motor da ficção de Luiz Ruffato e consistirá num jogo intenso entre lugar ideal e lugar real, ou seja, ao passo em que a personagem aspira a uma mudança situacional, a realidade que a engloba e, consequentemente, a aprisiona, lança-a novamente à situação precária que a constitui. Para validar a ocorrência desse desequilíbrio, refletiremos sobre os processos de modernização na América Latina, a possibilidade de aprisionamento do sujeito pelo espaço em que vive, e a probabilidade de as personagens criadas por Ruffato tentarem sempre voltar a um tempo inatingível e, mesmo que tendo o sonho negado pela realidade, não desistirem de buscar a (impossível) saída. Tendo isso em conta, procuramos refletir que a estratégia de dar voz à personagem de pior condição financeira através da ficção dá margem ao surgimento de um discurso subjetivo que, pela constituição social dessa personagem e pela ―realidade da ficção‖ criada pelo autor, acaba sendo estéril, levando-a a inércia. / This task is concerned to, even at a brief form, an analysis on the literary project of Luiz Ruffato, entitled Inferno provisório. It is our aim an ―inclusive criticism‖, which links references of the history, sociology and literary theory in order to elucidate some fiction aspects of the mineiro writer. The task is devided into four chapters. In the first chapters, we intend to analyse the formal aspects of Inferno provisório, like the filiation or not, on the books that compose it at the romance category; the construction of the narrator, lined by the plurality of voices at the construction of the tales and the language modulations carried out by Ruffato adopting what we will name as ―migrant writing‖, a writing lined by constant variation between the formal and colloquial registers. Still in the first chapter, we intend to identify in the title of the literary project (the junction between the terms ―inferno‖ and ―provisório‖) instruments for the interpretation and the critical reflexion around the fictional world created by the author, wich we will name ―fiction reality‖. The three subsequent chapters, will comprehend analysis of six histories in Inferno provisório attempting into reflecting about the possibility of, in these, exists the occurrence of instability between idealization and execution which comprehends the trajectories of the characters created by the author. This instability will act like the main mover of the fiction of Luiz Ruffato and it will consist of an intense play between ideal place and real place, it means, whereas the character aspires to a situational change, the reality which includes her and, consequently, confines her, projects her again into a precarious situation which composes her. In order to authenticate this instability occurrence, we will reflect about the improvement procedures in Latin America, the capturing possibility of the subject by the place it lives in, and the probability of the character created by Ruffato always arrempt into coming back to an unachievable period and, even having its dream denied by reality, never give up searching for a/an (impossible) solution. Taking that into account, we tried reflecting that the strategy of giving voice to the character of worst financial condition through the fiction brings up the emergence of a subjective speech that, based on the social formation of the character and ―fiction reality‖ created by the author, becomes infertile, turning it inert.

[pt] No presente trabalho se estuda um elemento finito subparamétrico que aproxima o campo de deslocamentos com funções spline, implementando um programa que pode ser utilizado para calculo estático, dinâmico e de instabilidade de estruturas compostas de placas, vigas de paredes finas, vigas caixão e em geral em elementos alongados (pontes e perfis metálicos). O grau de liberdade de rotação perpendicular ao plano do elemento é introduzido na formulação para possibilitar uma análise tridimensional. Apresenta-se um método que serve como base para determinar a constante de rigidez correspondente. Nos exemplos apresentados avalia-se a precisão obtida utilizando pouco número de divisões longitudinais do continuo, vantagem que justifica o uso desses elementos em estudos de pré-projeto ou otimização de estruturas. Comparam-se os resultados com soluções teóricas ou resultados de outros programas estruturais, permitindo apreciar as possibilidades e limitações da modelagem usando elementos finitos com funções spline. As diferenças observadas, que surgem principalmente em placas espessas, são explicadas pela aproximação da deformação de cisalhamento encontrada na literatura para os elementos utilizados na comparação. Mostra-se também exemplos de instabilidade analisados em três dimensões que permitem considerar diferentes condições de apoio e discutir os resultados de fórmulas conhecidas. / [en] The present work presents a subparametric finite element model with spline displacement functions, implemented for static, dynamic and instability analysis of folded plates, thin-walled beams, box girders, and elongated structures such as bridges and structural shapes. A drilling degree of freedom (rotation about an axis perpendicular to the plane of the element) is introduced in the formulation to allow for three-dimensional analysis. A method for determining the corresponding contribution to the stiffness matrix is presented. The examples presented evaluate the accuracy obtained using a small number of longitudinal subdivisions of the continuum, convenient in the case of analyses for preliminary design and optimization. The results obtained are compared to theoretical solutions or results of standard structural analysis programs, allowing for an appraisal of the advantages and limitations of modeling with use of spline functions. The differences in the results, observed specially in the case of thick plates, are explained by the approximations for the shear strain in the elements used for comparison. From the examples it is possible to comment results of threedimensional modeling of instability problems with different boundary conditions.

This thesis presents the ADT transverse instability detection system, the next generation of instability detection in the LHC at CERN, Geneva. The system is presented after a thorough study of underlying causes for instabilities in high energy particle accelerators, current parallel programming paradigms, the available hardware and software at CERN and possible instability detection techniques. The requirements for the system involve handling vast amounts of data which need to be analyzed in real-time and in this data detect rapid amplitude growth while limiting the computational resources required to a minimum. The result of this thesis was a system that could generate a trigger when an instability was detected, which was used to save data from observation instruments around the LHC. A fixed display in the CERN control centre was also created which allows scientists and operators at CERN to monitor the oscillation amplitude of all particle bunches. The conclusion is that the complete system will be a valuable asset at CERN to help further develop the LHC.

La stabilité d'un écoulement de couche limite sur une paroi verticale et d'un écoulement de canal entre deux parois verticales est étudiée en présence d'une stratification en densité. Des analyses de stabilité modale et non-modale sont conduites.Pour l'écoulement de couche limite sur une paroi verticale, l'analyse de stabilité temporelle est réalisé pour un profil de vitesse en tanh. Les caractéristiques sont décrites en fonction du nombre de Reynolds (Re) et du nombre de Froude (F). Je montre que l'écoulement de couche limite est sujet à l'instabilité visqueuse et à l'instabilité radiative qui conduisent respectivement à la formation d'ondes de Tollmien-Schlichting (TS) et à la génération spontanée d'ondes internes. Je montre que l'instabilité radiative diminue le nombre de Reynolds critique et domine l'instabilité visqueuse pour des grands nombres de Reynolds. L'instabilité radiative devrait donc être observable dans les expériences et les écoulements géophysiques atmosphériques ou océaniques. Pour l'écoulement de canal, je réalise une étude de stabilité temporelle ainsi qu'une étude des perturbations optimales en utilisant le profil de vitesse de Poiseuille. Comme pour l'écoulement de couche limite, je montre que l'instabilité visqueuse est dominée par une instabilité 3D associée à la stratification. Cette dernière affecte également la croissance transitoire des perturbations. Les deux mécanismes fondamentaux de croissance transitoire que sont les mécanismes de Orr et de ``lift-up'' sont toujours présents mais le mécanisme de lift-up est fortement atténuée par la stratification et rapidement dominée par la présence des instabilités 3D. / The stability of a boundary layer on a vertical wall and a channel flow between two vertical walls is studied in the presence of density stratification. Both modal and non-modal analysis are conducted in these studies. For the boundary layer on a vertical wall, a temporal stability analysis is performed for a tanh velocity profile. The characteristics are analysed as functions of the Reynolds number (Re) and the Froude number (F). The boundary layer is found to be unstable to viscous instability and radiative instability. The viscous instability can lead to Tollmien–Schlichting (TS) waves, and the radiative instability may generate internal gravity waves spontaneously. The radiative instability reduces the critical Re for instability. And for large Reynolds numbers, it dominates the viscous instability. Consequently, radiative instability may develop in experiments and various geophysical situations in the ocean and atmosphere.For the channel flow, we choose plane Poiseuille flow as a prototype. Both the exponential instability and transient growth are analysed. There are also two kinds of exponential instabilities, viscous instability and a 3D instability. The 3D instability influences the behaviour of the transient growth. The fundamental mechanisms in transient growth are the inclination of upstream tilting waves and the growth of streamwise vortices, which are referred to as Orr mechanism and lift-up mechanism. In the presence of stratification, the Orr mechanism is not affected while the lift-up mechanism is weakened. The combination of these two mechanisms is amplified by the influence of the 3D instabilities.

Les aciers ferritiques pour structures industrielles présentent une transition fragile-ductile de ténacité et de résilience avec leur température. Leur résistance à la rupture fragile joue un rôle essentiel dans la certification de la sécurité des structures industrielles importantes. De nos jours, le souci de performance et de longévité sont des points clés pour des acteurs majeurs comme EDF.Dans ces études de transition ductile-fragile, de ténacité et de résilience, la ténacité est prédite à partir de la résilience. Plusieurs travaux antérieurs ont déjà montré que la probabilité de rupture par clivage peut être correctement décrite dans le palier fragile par une approche locale de la rupture. Mais ces études supposent que le matériau ne subit pas de vieillissement sous déformation, ce qui est en fait rarement pertinent pour les aciers bas carbone et peu calmés. Le travail a consisté d'une part à caractériser le comportement et d'autre part à en proposer une modélisation robuste et explicite des phénomènes observés. La caractérisation a consisté en la réalisation d'essais de traction entre -150°C et 20°C à plusieurs vitesses de déformation. Un modèle capable de simuler le vieillissement statique est identifié en mettant en place une stratégie adéquate et systématique. Des essais de résilience permettent de construire la courbe de transition ductile-fragile du matériau pour différentes conditions afin de comprendre et d'observer l'influence du vieillissement statique sur la rupture. Enfin, la modélisation de la rupture fragile a été décrite pour toutes les conditions expérimentales testées en utilisant le modèle de comportement développé et identifié dans la partie précédente afin de prédire numériquement la transition pour les différentes conditions du matériau. / Ferritic steels for industrial structures have a brittle-ductile transition toughness and impact energy with temperature. Their resistance to the brittle fracture plays an essential role in the safety certification of industrial structures. Nowadays, the performance and the durability are key issues for major players such as EDF. In these approaches ductile-to-brittle transition toughness and impact energy, toughness is predicted from resilience. Several previous studies have shown that the probability of cleavage fracture can be adequately described in brittle plateau by a local approach to fracture. However, these studies assume that the material does not undergo strain aging, which is rarely relevant for low carbon steels and low calmed down. The work consisted firstly to characterize the behavior and secondly to propose a robust and explicit modeling of the observed phenomena. Characterization consisted of performing tensile tests between -150degreC~and 20degreC for several strain rates. A model able to simulate the static aging is identified by implementing an appropriate and systematic strategy. Impact resistance test allows us to build the curve of ductile-to-brittle transition of the material for different conditions to understand and observe the influence of static strain aging on the failure. Finally, the modeling of the brittle fracture has been described for all experimental conditions tested using the model developed and identified in the previous section to predict the transition for different material conditions.

L'instabilité microsatellitaire (MSI) résulte d'une déficience du système de réparation des mésappariements de l'ADN. Cette instabilité est observée dans 10-15% des tumeurs chez l'Homme, incluant les cancers colorectaux (CCR) et de l'estomac (CG). En 2011, notre laboratoire a rapporté la mutation de la chaperonne HSP110 dans les CCR MSI. Cette mutation affecte un microsatellite intronique de 17 thymidines (T17), localisé au niveau de l'intron 8. Les grandes délétions somatiques du T17 (? 5 paires de bases), représentant 25% des CCR MSI, conduisent à l'inactivation complète de la chaperonne HSP110 dans les CCR MSI. De manière remarquable, ces grandes délétions sont prédictives chez les patients d'une excellente réponse à la chimiothérapie adjuvante. Au cours de ma thèse, mes travaux ont visé à étudier l'impact de la mutation d'HSP110 dans les tumeurs gastro-intestinales MSI. Mes résultats démontrent que la mutation du microsatellite T17 d'HSP110 a pour conséquence une diminution de la prolifération cellulaire en partie lié à la diminution de la phosphorylation du facteur de transcription STAT3. En outre, mes résultats suggèrent que cette mutation serait un facteur prédictif de survie chez les patients atteint de CG, indiquant le potentiel théranostique d'HSP110. Enfin, je propose une approche thérapeutique innovante pour les patients atteints de CCR MSI, basée sur la potentialisation de l'expression de transcrits mutants, codant pour des protéines délétères pour la cellule tumorale, à l'instar du dominant négatif HSP110DE9 résultant de la mutation d'HSP110 dont l'ARN semble être régulé par le système NMD (Nonsense-Mediated mRNA Decay). / Microsatellite instability (MSI) results from impaired DNA mismatch repair, being observed in 10-15% of frequent tumors in human, e.g. Colorectal (CRC), Gastric Cancers (GC) and others. In 2011, frequent somatic mutations of the HSP110 chaperone have been reported in MSI CRC by my lab, affecting a T17 intronic DNA repeat located in intron 8. Large (≥ 5 base pairs) bi-allelic somatic deletions of this DNA repeat in tumor DNAs, as observed in about 25% of MSI CRC, lead to complete inactivation of HSP110 by exon 9 skipping and sensitization of tumor cells to chemotherapy. These large deletions are predictive of improved response to adjuvant chemotherapy in CRC patients. During my PhD thesis, I further investigated the role of HSP110 in MSI tumors. My results demonstrate that HSP110 mutation leads to cell proliferation decrease through the reduction of STAT3 transcription factor phosphorylation in CRC tumors (Berthenet*, Bokhari*, et al., Oncogene 2016). Furthermore, I showed that HSP110 mutation is also frequently observed in MSI gastric cancer, leading to very similar pathophysiological consequences during tumor progression and improved patient’s survival independently from tumor stage (Cervera*, Lagrange*, Bokhari* et al., submitted). Finally, I worked on an innovative therapeutic approach that consisted in inhibiting the NMD (Nonsense-Mediated mRNA Decay) system, an ubiquitous process recognizing and degrading mRNAs containing premature termination codons (PTC). The inhibition of NMD leads to the expression of deleterious MSI-driven mutant transcripts such as the HSP110DE9, coding for a dominant negative mutant, derived from HSP110 mutation in MSI cancer cells.

Les hélicases sont des enzymes ubiquitaires catalysant la séparation de l’ADN double-brin et impliquées dans la réplication, la réparation de l’ADN et dans le maintien des télomères. Chez l’Homme, 3 hélicases présentent des mutations responsables de syndromes cliniques : WRN pour le syndrome de Werner, BLM pour le syndrome de Bloom et RECQL4 pour le syndrome de Rothmund-Thomson. Tous ces syndromes associent un vieillissement pathologique accéléré à un risque accru de développement de cancer notamment par une augmentation de l’instabilité génomique. Les connaissances sur les mécanismes moléculaires et cellulaires impliqués dans ces maladies du vieillissement sont encore très partielles, notamment en ce qui concerne le lien entre l’instabilité génomique et le vieillissement. Au cours de ce projet, l'utilisation de prélèvements sanguins et cutanés de patients atteints de ces pathologies rares a permis de générer des modèles de cellules souches pluripotentes induites (iPS). Ces cellules présentent l’avantage de s’auto-renouveler et de pouvoir théoriquement se différencier dans tous les types cellulaires d’un organisme. Parallèlement, un témoin de sénescence a été généré de la même manière avec des cellules d’un patient souffrant du syndrome de la progéria de Hutchinson-Gilford. Après caractérisation de ces cellules, nous avons identifié des ensembles de phénotypes cellulaires et moléculaires dans le but de récapituler in vitro les pathologies. Nous avons également engagé les cellules iPS dans des voies de différenciation proches des tissus atteints dans les pathologies in vivo. Enfin, nous avons étudié la stabilité génomique de ces lignées dans les différents types cellulaires cultivés. Ainsi nous avons observé que la lignée Bloom est le siège de recombinaisons particulièrement fréquentes et est caractérisée par une instabilité du génome dans tous les types cellulaires étudiés. Egalement, la lignée Werner semblerait se distinguer par une instabilité de ses télomères. Enfin, l’ensemble des lignées des pathologies du vieillissement prématuré présenterait un défaut mitochondrial. / Helicases process the double-stranded DNA dissociation. They are involved in replication, DNA repair and maintenance of telomeres. In human, 3 helicases display mutations responsible for clinical syndromes: WRN for the Werner syndrome, BLM for the Bloom syndrome and RECQL4 for the Rothmund-Thomson syndrome. All these diseases cause premature ageing and high risk of cancer. Molecular and cellular mechanisms involved in these diseases are not well defined. Particularly, little is known concerning the link between genomic instability and ageing. During this project, we used blood samples and skin biopsies of affected patients to generate models by reprogramming cells to induced pluripotent stem cells (iPSCs). These cells have the advantage of self-renewing and theoretically could be differentiated in all cell types. At the same time, an iPSC senescence control was performed from cells of a Hutchinson-Gilford Progeria syndrome patient. iPSCs were characterized for pluripotency. In the aim of recapitulate these pathologies in vitro, we identified sets of cellular and molecular phenotypes. We also engaged differentiation of iPSCs in cell pathways closed to the affected tissues in vivo. Finally, we studied the genomic stability of iPSCs and derived cells. We observed that Bloom cells are susceptible to frequent recombinations and are characterized by a genome instability through all studied cell types. Werner cells showed an instability of telomeres length. Finally, all premature ageing diseases displayed mitochondrial defects.

The problem of spatial disorientation during flight of aircraft is briefly described, as are definitions of the phenomenon. Traditional countermeasure efforts that are often directed towards changes in the central visual field are reconsidered in favour of presentation of information in the peripheral visual field. It is proposed to use optic flow to support spatial orientation, as well as to omit such information from the central visual field. An experiment was conducted, and results showed that forward visual flow gave very important spatial information. The flow could be cropped to a certain degree in the periphery (horizontally), as well as parts of the central presentation could be omitted without decreasing effects in the experiment. Implications relevant to possible implementations in aircraft are discussed.

Hyman Minsky’s Financial Instability Hypothesis is used to construct two different indices for financial instability: a long-term index (Long Term Financial Instability) and a short-term index (Short Term Financial Instability). The former focuses on the underlying fragility of financial structures of units in the economy while the latter focuses on more immediate developments and manages to follow turmoil – “a financial crisis” – in the economy. The interplay of the indices with each other, with economic growth and with Foreign Direct Investment, both in general and in the financial industry, is probed. In short, we find that long term financial stability, i.e. secure financial structures in the economy or a low level of Long Term Financial Instability, is sacrificed for maintaining short term financial stability. However, more Long Term Financial Instability is associated, as Minsky expected, with more fluctuations in Short Term Financial Instability: market turmoil is more common the more fragile underlying financial structures of units in the economy are. This signals that markets are ruled by short-termism. Economic growth is harmed by Short Term Financial Instability but the effects of Long Term Financial Instability are weaker. The common expectation that FDI activities strengthen financial stability is not confirmed. The relationship found hints rather in the opposite direction: FDI activities seem to cause financial instability. Based on the those investigations and a further empirical work using data from Iceland, Leigh Harkness’s Optimum Exchange Rate System (OERS) is developed further with the intention of solving “The Policy Problem” as described by Minsky. Insights from control theory are used. The OERS, along with public debt management as carried out by Keynes, is argued to have the ability to keep economic activity in the state of a permanent “quasi-boom”. The policy implications are that the OERS should be considered as a monetary policy as it permits a free flow of capital, thereby allowing economies to reap the possible positive benefits of foreign direct investment, while still conserving financial stability.

Cette thèse porte sur les effets combinés de l’excentricité et du débit axial sur les propriétés de stabilité linéaire de l’écoulement de Couette circulaire avec cylindre extérieur fixe. Cet écoulement intervient, entre autres, lors du forage de puits de pétrole. Une méthode pseudospectrale est mise en oeuvre pour calculer l’écoulement de base, stationnaire et invariant suivant la direction axiale, ainsi que les modes normaux d’instabilité. L’écoulement est régi par quatre paramètres adimensionnels : rapport de rayons _ et excentricité e pour la géométrie, nombres de Reynolds azimuthal et axial, Re et Rez, pour la dynamique. La première partie de l’étude est consacrée aux propriétés de stabilité temporelle. Il apparaît que l’excentricité repousse le seuil d’instabilité convective vers de plus fortes valeurs de Re. L’effet de l’advection axiale sur le seuil est principalement stabilisant également. L’excentricité a pour conséquence de déformer la structure des modes par rapport au cas concentrique. Le mode au plus fort taux de croissance temporelle est ainsi constitué de tourbillons de Taylor « pseudo-toroïdaux » lorsque le débit axial est nul, et de structures « pseudo-hélicoïdales » d’ordre azimuthal croissant lorsque Rez augmente. Les résultats sont qualitativement similaires lorsque l’on change le rapport de rayons. Les prédictions théoriques sont en bon accord avec les quelques résultats expérimentaux disponibles. Dans une seconde partie, l’instabilité absolue est étudiée par application d’un critère de point selle à la relation de dispersion. Le débit axial a pour effet d’inhiber fortement l’instabilité absolue, d’origine centrifuge, et la valeur de Re au seuil est typiquement supérieure à celle de Rez d’un ordre de grandeur. L’effet de l’excentricité est plus complexe : légère stabilisation aux faibles valeurs de e, puis déstabilisation marquée aux excentricités modérées lorsque Rez est suffisament grand, et enfin stabilisation lorsque e croît davantage. Contrairement au cas de l’instabilité convective, le mode dominant l’instabilité absolue correspond à l’écoulement tourbillonnaire « pseudo-toroïdal » pour toute la gamme de paramètres considérée. / This work is concerned with the combined effects of eccentricity and pressure-driven axial flow on the linear stability properties of circular Couette flow with a fixed outer cylinder. An example of this flow can be found in oil-well drilling operations. A pseudospectral method is implemented to compute the basic flow, steady and homogeneous in the axial direction, as well as the normal modes of instability. There are four non-dimensional parameters: the radius ratio _ and the eccentricity e for the geometry, the azimuthal and axial Reynolds numbers, Re and Rez, for the dynamics. The first part of the study is devoted to the temporal stability properties. It is found that eccentricity pushes the convective instability threshold towards higher values of Re. The effect of axial advection on the threshold also tends to be stabilising. Eccentricity deforms the modes structure compared to the concentric case. As a result, the mode with the largest temporal growth rate takes the form of ‘pseudo-toroidal’ Taylor vortices in the absence of axial flow, and ‘pseudo-helical’ structures with increasing azimuthal order as Rez becomes larger. Results are qualitatively similar for different radius ratios. Agreement with the few available experimental data is good. In a second part, absolute instability is studied by applying the pinch-point criterion to the dispersion relation. Axial flow is found to strongly inhibit absolute instability, the mechanism of which being centrifugal, and the value of Re at the threshold is typically one order of magnitude larger than that of Rez. The effect of eccentricity is more complex: weak stabilisation for low values of e, marked destabilisation for moderate eccentricities and high enough Rez, and finally stabilisation as e is further increased. Unlike temporal instability, the dominant absolutely unstable mode is the ‘pseudo-toroidal’ Taylor vortex flow over the whole range of parameter space considered.