Bob Dylan, the ordinary star

This paper provides a study of Bob Dylan's public image as a star performer and what he represented for his audiences within the framework of 1960s counterculture. I will begin with an interpretation of his public image at the rise of his career in an effort to better understand how Dylan came to be considered a social symbol and a representative of a historically specific counterculture as the voice of a young frustrated generation. This study will focus primarily on D. A. Pennebaker's documentary Don't Look Back, which portrays a 23-year old Dylan on his 1965 English tour. Ultimately, we will see how this film brilliantly captures the paradox of Dylan's star popularity in light of his refusal to portray the star his audience wanted and expected. This was not only a personal struggle but a cultural contradiction.Note: The Peformance Artistry of Bob Dylan: Conference Proceedings of the Caen Colloquiu

OIM analysis of microstructure and texture of a TRIP assisted steel after static and dynamic deformation

TRIP-assisted steel with a composition of 0.2%C, 1.6%Mn, 1.5%Al was studied in the undeformed state, after the application of 10 and 30 % static tensile strain parallel to rolling the direction of the sheet and after dynamic (Hopkinson) fracture test. Detailed examination of the microstructure and microtexture by means of electron backscattered diffraction (EBSD) was carried out in order to quantify the microstructural constituents and to study the strain distribution. The microtexture evolution and the distribution of the specific texture components between the BCC and FCC phases were studied as a function of the external strain and the strain mode-static or dynamic. The strain localization and strain distribution between the structural constituents were quantified based on local misorientation maps. The full constraint Taylor model was used to predict the texture changes in the material and the results were compared to the experimental findings. Comparing the local misorientation data it was found that at low strains the ferrite accommodates approximately 10 times more deformation than the retained austenite. The strain localizes initially on the BCC-FCC phase boundaries and is then spread in the BCC constituents (ferrite and bainite) creating a deformation skeleton in the BCC phase. It was found that the observed texture changes in the measured retained austenite texture after deformation do not correspond exactly to the model prediction. The austenite texture components which were predicted by the Taylor model were not found in the measured austenite texture after deformation which means that they are first transformed to martensite, which is considered as an indication for the selective transformation of austenite under strain

Rôle de la sphingosine kinase 1 dans la régulation de l'hypoxie intratumorale

L'hypoxie est une caractéristique des tumeurs solides qui contrôle la mise en place des voies de signalisation impliquées dans la néovascularisation, l'apparition de métastases, l'augmentation de la croissance tumorale et la résistance aux traitements. L'activation du facteur HIF-1 (Hypoxia Inducible Factor 1) a été identifiée comme le mécanisme principal de l'adaptation au stress hypoxique. Bien que les premières études aient principalement porté sur le rôle de HIF-1, de nombreux travaux soulignent l'importance de HIF-2 dans la régulation de certains gènes et fonctions biologiques. Le facteur HIF-2, présentant une Forte homologie avec HIF-1, joue notamment un rôle clef dans la progression des cancers rénaux à cellules claires (ccRCC). Nous avons précédemment identifié la voie Sphingosine Kinase-1/ sphingosine 1-phosphate (SphK1/S1P), impliquée dans de nombreux processus dont l'angiogenèse, prolifération et la survie cellulaire, en tant que nouveau modulateur de l'activité de HIF-1. Considérant le rôle crucial de HIF-2 dans les ccRCC, il est essentiel de mieux comprendre le rôle de la SphK1 dans la régulation de HIF-2a dans ces modèles. Dans ce but, les mécanismes de régulation du taux de HIF-2a et de l'activité de HIF-2 par la SphK1 ont été étudiés. Cette étude in vitro a été réalisée in vitro dans de nombreux modèles de ccRCC possédant des profils d'expression de HIF-1a et HIF-2a différents et représentant l'ensemble des groupes retrouvés en clinique humaine (expression de HIF-1a et de HIF-2a ou de HIF-2a seul). De manière intéressante, nos résultats indiquent que la SphK1 régule le taux de HIF-2a dans les différents modèles cellulaires, dont les ccRCC. Dans toutes ces lignées l'inhibition de la SphK1 entraîne une diminution du taux de HIF-2a ainsi qu'une diminution de l'expression des gènes cibles de HIF-2. Dans les lignées de ccRCC, la SphK1 stimule la traduction de HIF-2 via l'activation des protéines mTOR et p70S6K. En amont, nous avons établi que la phospholipase D (PLD) était responsable de l'activation de la SphK1 et que l'inhibition de la PLD conduisait à une diminution de l'activité de la SphK1 et du taux de HIF-2a. De plus, l'inhibition de la formation des espèces réactives de l'oxygène (ROS) bloque l'activation de la voie PLD/SphK1/HIF-2a. Nous avons ainsi identifié la voie ROS/PLD/SphK1 comme une nouvelle voie de régulation du facteur HIF-2a. Ce travail a permis d'identifier la SphK1 comme régulateur clef du facteur HIF-2 démontrant l'intérêt thérapeutique de cibler la SphK1 dans le cas des cancers où HIF-2 joue un rôle prépondérant tels que les cancers rénaux, pulmonaires et les neuroblastomes.Hypoxia is a characteristic of solid tumors that triggers the activation of signaling pathways promoting neovascularization, metastasis, increased tumor growth and resistance to treatments. The activation of the transcription factor hypoxia-inducible factor 1 (HIF-1) has been identified as the master mechanism of adaptation to hypoxia. Whereas initial characterization of hypoxia-induced transcription emphasized on HIF-1, there is now evidence that HIF-2, which is closely related to HIF-1, could regulate unique genes and physiological functions. Notably, HIF-2, rather than HIF-1, has been shown to play a critical role in clear cell renal carcinoma (ccRCC). We have previously identified the sphingosine kinase-1/sphingosine 1-phosphate (SphK1/S1P) pathway - which elicits various cellular processes including cell proliferation, cell survival or angiogenesis - as a new modulator of HIF-1 activity. Considering the crucial role of HIF-2 in ccRCC, it was essential to understand the role of the SphK1 signaling in these tumors. To this end, the mechanisms underlying the regulation of HIF-2a level and activity, via the SphK1 signaling, have been investigated. These in vitro studies have been conducted in various ccRCC models exhibiting different HIF-1a and HIF-2a status, and representing all the sub-groups found in human clinic (which can produce either HIF-1a and HIF-2a or HIF-2a alone). Our data indicate that SphK1 regulates HIF-2a level in several cancer cell models including ccRCC. Depletion of SphK1 decreased HIF-2a level and consequently resulted in decreased expression levels of HIF-2a responsive genes. In ccRCC, SphK1 stimulates translation of HIF-2a via p70-S6kinase and mTOR pathway. Upstream, we have established that Phospholipase D (PLD) is responsible for the up-regulation of SphK1, and that inhibition of PLD leads to a decrease in SphK1 activity and in HIF-2a level and activity. Moreover inhibition of reactive oxygen species (ROS) production abolished PLD/SphK1/ HIF-2a pathway. Overall, we have identified a new molecular mecanism whereby a ROS/ PLD/SphK1 signaling pathway regulates HIF-2a. We provide evidence that SphK1 act as a master regulator for HIF-2a and giving support to its inhibition as a valid strategy for ccRCC and others cancers for which HIF-2a is particularly relevant (lung, neuroblastoma)

Low cycle fatigue behaviour of a precipitation hardened Cu-Ni-Si alloy

International audienceLow cycle fatigue tests were performed at room temperature to investigate the role of the microstructure of a Cu-Ni-Si alloy on the stress response to strain cycling and on the fatigue resistance. The cyclic accommodation consisted in a hardening followed by a softening. TEM analysis showed that in some grains dislocations remained isolated and confined between precipitates while in other grains dislocations piled up at δ-Ni 2 Si precipitates and then cut them. Repetitive cutting allows their dissolution and formation of precipitate-free bands where the plastic deformation is localised. The Manson-Coffin diagram exhibited two regimes according to the proportion of grains involved in the plastic deformation accommodation

Static and impact-dynamic characterization of multiphase TRIP steels

In this study, results are presented of an extensive experimental program to investigate the strain rate dependent mechanical properties of various Transformation Induced Plasticity (TRIP) steel grades. A split Hopkinson tensile bar setup was used for the high strain rate experiments and microstructural observation techniques such as LOM, SEM and EBSD revealed the mechanisms governing the observed behavior. With elevated testing temperatures and interrupted tensile experiments the material behavior and the austenite to martensite transformation is investigated. In dynamic conditions, the strain rate has limited influence on the material properties. Yet an important increase is noticed when comparing static to dynamic conditions. The differences in strength, elongation and energy absorption levels observed between the investigated materials can be attributed to their chemical composition. Adiabatic heating during high strain rate deformation tends to slow down the strain induced martensitic deformation. The elongation of the ferritic and austenite constituents is found to be strain rate dependent and the strain induced martensitic transformation occurs gradually in the material

Automatic Modelica BEM generation from IFC BIM

The emergence of BIM-assisted building digital twins is facilitating building digitalization efforts across various domains. These digital twins necessitate the creation of building energy models (BEM) derived from BIM data. These models are crucial for conducting building simulations, which in turn evaluate the thermal performance of buildings. To address this need, this study presents a semi-automated workflow for converting BIM data into BEMs. Specifically, the workflow utilizes IFC BIMs generated from point cloud data obtained through building scans. Manual intervention in this workflow is minimal, primarily focusing on detecting and correcting errors in BIM geometry resulting from the semi-automatic conversion of point cloud data to BIM format. The process is applied to an existing office building

Irreversible reduction of foil tension due to aerodynamical effects

Computation of the residual stress generated during the winding of a plastic film has been coped with by many authors. These studies are based on the assumption that the residual stresses mainly depend on two winding factors: (i) nominal foil tension and (ii) foil mechanical properties. Recently, several authors have introduced the effects of a third winding factor: nip force. But, in all the existing studies, the influence of the entrapped air layer and more generally, the aerodynamical effects are neglected.Such an assumption is reasonable in the case of thick plastic film (thickness about 100 μm) or thin plastic films (thickness about 10 μm) wound under low velocities (about 1 m.s-1). However, in the case of industrial winding conditions in which film thickness is typically about 10 μm and velocity about 5 m.s-1, the effects of aerodynamical phenomena are experimentally known to be as important as the effects of foil tension itself.From a more general point of view, the industrial winding conditions suffer from a lack of theoretical analysis since they are mainly based on empirism, which is not quite satisfactory.We recently proposed a model in order to predict the residual stresses generated under realistic industrial conditions, including the effect of nip roll. This model is based on a new global approach in which the Winding process is seen as a mechanism of air entrainment and air exhaust To set this model in order, we were faced with several problems: (i) computation of the thickness of the entrained air layer, (ii) analysis of the air exhaust phenomena, (iii) analysis of effects due to film roughness ... All the main parameters which govern the winding process (velocity, foil tension, nip force, foil bulk and surface properties ... ) are taken into account.In the present paper, we propose to recall the basis of this new global approach and to focus our attention on one of its most important consequences: the irreversible reduction of foil tension during and after winding. Experimental check is presented for a large set of winding conditions. Comparison is based on the average air layer thickness and on the foil residual tension value

Investigation of the microstructure and properties of TRIP 800 steel subjected to low-cycle fatigue

The present work describes in detail the heterogeneousmicrostructure evolution of a high-strength steel (TRIP 800 steel) at the low-cycle fatigue conditions. Based on the extended investigations (via the optical and electron microscopy, the electron backscattering diffraction), we propose suggestions on the influence of phase composition on the mechanical properties and the crack-initiation processes. The preferential places of the crack nucleation caused by fatigue are detected, and the completeness of phase transformation via the induced plasticity is evaluated.Дана робота детально описує гетерогенну еволюцію мікроструктури високоміцної криці (TRIP 800) за умов малоциклової втоми. На підставі розширених досліджень (оптичною й електронною мікроскопією, дифракцією зворотнього розсіяння електронів) запропоновано рекомендації щодо впливу фазового складу на механічні властивості та процеси зародження тріщин. Виявлено осередки переважного зародження тріщини, спричинені втомою, й оцінено повноту фазового перетворення за рахунок індукованої пластичності.Данная работа подробно описывает гетерогенную эволюцию микроструктуры высокопрочной стали (TRIP 800) в условиях малоцикловой усталости. На основании расширенных исследований (оптической и электронной микроскопией, дифракцией обратного рассеяния электронов) предложены рекомендации относительно влияния фазового состава на механические свойства и процессы зарождения трещин. Обнаружены очаги предпочтительного зарождения трещины, что вызвано усталостью, и оценена полнота фазового превращения за счёт индуцированной пластичности