777 research outputs found
Data for `Abnormal vasculature reduces overlap between drugs and oxygen in a tumour computational model: implications for therapeutic efficacy`
No full textThis dataset contains the results of the drug and oxygen transport simulations in tumour and tumour decompressed microvascular networks published in the work "Abnormal vasculature reduces overlap between drugs and oxygen in a tumour computational model: implications for therapeutic efficacy"
Blood flow through compressed networks - critical bifurcations
No full textThe tumour microenvironment is abnormal and one of its consequences is that blood vessels are compressed. Vessel compression correlates with reduced survival rates, while decompression of vessels improves tissue oxygenation as well as increases survival rates. It was previously shown that vessel compression contributes, at a single vascular bifurcation, to the increase of heterogeneity of red blood cell transport. This dataset contains the result of a simulation of blood flow (Poiseuille flow) through a compressed network, showing the effect of vessel compression on haematocrit distribution. It additionally contains the critical bifurcations in the network that are responsible for diverting blood flow away from the compressed region
HemeLB vessel compression simulation data
No full textThis dataset contains the files to reproduce the HemeLB simulations for the effect of a vessel compression on a downstream bifurcation. In addition, one of the key outputs of the simulations is provided
On abnormal microvascular phenotypes in a mouse model of glioblastoma and the effect of vessel compression on blood flow
Get PDFCancer is a major healthcare concern in the world, accounting for one in six deaths. Despite
this, cancer patient survival rates have increased over the past decades as a result of healthcare
improvement reforms and advances in medical research. Among the numerous areas
of research in cancer, studying the tumour microenvironment and the physics of cancer has
shown promising results for patient benefit, and will be the focus of this thesis.
A tumour is an abnormal cell growth, and is cancerous when it has the potential to metastasise.
Tumours have their own microenvironment which presents numerous abnormalities
compared to healthy tissue. In particular, as tumours grow they develop their own microvascular
system to transport nutrients and oxygen to the cells. However, the tumour vasculature
is abnormal and inefficient, leading to an abnormal microenvironment, with traits such as
hypoxia. Hypoxia leads to more aggressive tumours and is a barrier to treatment, making it an
undesirable trait. A better understanding of the causes of tumour hypoxia could thus benefit
patient care.
One tumour vessel abnormality is vessel compression, which is the result of high solid stress
in tumours. Studies have shown that vessel compression correlates with reduced survival
rates, and increased hypoxia and oxygen heterogeneity. However, the biophysical mechanism
which links compressed vessels to hypoxia is not clear. In addition, vessel compression
has not been characterised in glioblastoma multiforme brain tumours, despite the correlation
between vessel compression and reduced survival rates, and the low survival rates of
glioblastoma patients.
As red blood cells transport oxygen in blood, the central hypothesis of this thesis is that vessel
compression leads to abnormal transport of red blood cells, contributing to tissue hypoxia.
Therefore, the aim of this work is to find a mechanistic link between vessel compression and
abnormal red blood cell transport in compressed vascular networks and contextualise it to
glioblastoma.
The first results chapter investigates the effect of a compression on the partitioning of red
blood cells at a downstream bifurcation. The numerical experiment shows that, with a compressed
parent branch, the higher flowing child branch is enriched in red blood cells compared
to a control simulation. The abnormal partitioning of red blood cells is the result of a
narrowing of the red blood cell cross-sectional distribution as they enter the compression.
Indeed, in the compression the red blood cells undergo cross-streamline migration to more
central streamlines as a result of the increased shear rate and shear rate gradient in the
compression. The results further show that the abnormal partitioning of red blood cells is
present over a wide range of flow ratios to the child branches. The abnormal partitioning of
red blood cells becomes less pronounced as the parent branch haematocrit increases, up to
a critical threshold of around 30%, above which abnormal partitioning no longer occurs.
The second results chapter builds on to the first one and numerically investigates how the
abnormal partitioning of red blood cells at a single bifurcation propagates at a network level.
To do so, it adapts and validates an existing reduced-order model to accurately and efficiently
calculate the abnormal partitioning of red blood cells when parent branches are compressed.
At a network level, and compared to a control, vessel compression increases haematocrit heterogeneity,
reduces the average haematocrit, and increases the number of plasma channels
present. The mechanisms for these findings are investigated and show that both the increased
resistance to flow and the abnormal partitioning of red blood cells at a bifurcation contribute to
lowering the haematocrit in the networks, but that haematocrit heterogeneity is only the result
of the abnormal partitioning of red blood cells. Finally, it is shown that the reduction in average
haematocrit in the networks occurs over a wide range of inlet haematocrits, and that only a
relatively small number of vessels need to be compressed for the reduction to be present.
The final results chapter phenotypes and compares the microvasculature in a mouse model of
a glioblastoma to control mice. A pipeline is developed and validated to reconstruct the threedimensional
vessel surfaces from multiphoton microscopy images of the vasculature. The data
show that the non-dimensional interbifurcation distance and the mean tissue-vessel distance
are significantly lower in tumours, but that other phenotypes are not different. Notably, the
tumour vessels were not compressed. Furthermore, the results show that there is a correlation
between the mean tissue-vessel distance in a region of interest and the distance of the region
of interest from the tumour core.
Taken together, these findings address the aim of this thesis and provide a mechanism for
abnormal transport of red blood cells in compressed vessel networks. Due to the importance
of red blood cells in the transport of oxygen, this work contributes to the knowledge of the
causes of hypoxia in tumours with vessel compression. As hypoxia is an important trait adversely
affecting patient prognosis, understanding the mechanisms leading to hypoxia has the
potential, in the long term, to inform patient care
Vilnius citizen Romain Gary
No full textReikšminiai žodžiai: II pasaulinis karas; Istorija; Prancūzija (France); Prancūzų autorius; Romain Gary; Romain Gary de Kacev; Romainas Gary; Romanas; Vilnius; France; French author; History; Lithuania; Novel; Romain Gary; Romain Gary de Kacev; Vilnius; World War IIThe mosi read French author in the whole world: 30 books in French, six books in English. Neither of these languages was his native tongue. Born in Vilnius on 8 May 1914, he recalled the city nostalgically, but after leaving it he never visited it again. He and his mother believed in his future fate, and it all came true: he became a famous writer, a French hero, and dressed as if he was in London. He wrote many of his books under pseudonyms, and often changed them. He created his work, and he also created himself. It often seemed to him that there was someone else inside him. Maybe it was always that dreamy boy from Pohulianka, ready to take any risk for the sake of beauty. He has no grave. The only monument to the writer Romain GARY is in Vilnius, his home town. Gary is presented to us by the translator Dalija Epšteinaitė
Electroencéphalographie et interfaces cerveau-machine : nouvelles méthodes pour étudier les états mentaux
No full textAvec les avancées technologiques dans le domaine de l'imagerie cérébrale fonctionnelle et les progrès théoriques dans la connaissance des différents éléments neurophysiologiques liés à la cognition, les deux dernières décennies ont vu l'apparition d'interfaces cerveau-machine (ICM) permettant à une personne d'observer en temps réel, ou avec un décalage qui se limite à quelques secondes, sa propre activité cérébrale. Le domaine clinique en général, et plus particulièrement celui de la neuropsychologie et des pathologies conduisant à un handicap moteur lourd, pour lesquels les applications potentielles sont nombreuses qu'elles soient thérapeutiques ou en vue d'une réhabilitation fonctionnelle, a constitué un moteur important de la recherche sur ce nouveau domaine des neurosciences temps réel. Parmi ces applications, le neurofeedback, ou neurothérapie, qui vise l'acquisition par le sujet du contrôle volontaire de certains aspects de son activité cérébrale en vue de les amplifier ou au contraire les diminuer dans un but thérapeutique, voire d'optimisation cognitive, représente une technique prometteuse, alternative aux thérapies et traitements médicamenteux. Cependant, la validation de ce type d'intervention et la compréhension des mécanismes mis en jeux en sont encore à leurs balbutiements. L'entraînement par neurofeedback est souvent long, pouvant s'étaler sur plusieurs semaines. Il est donc très probable que ce type de rééducation cérébrale sollicite des phénomènes de plasticité qui s'inscrivent dans une dynamique lente, et de ce fait, requiert une durée relativement longue d'entraînement pour atteindre les effets à long terme recherchés. Cependant, à cela peuvent s'ajouter de nombreux éléments perturbateurs qui pourraient être à l'origine de la difficulté de l'apprentissage et des longs entraînements nécessaires pour obtenir les résultats attendus. Parmi eux, les perturbations qui viennent déformer le signal enregistré, ou les éléments artefactuels qui ne font pas partie du signal d'intérêt, sont une première cause potentielle. Le manque de spécificité fonctionnelle du signal retourné au sujet pourrait en constituer une deuxième. Nous avons d'une part développé des outils méthodologiques de traitement du signal en vue d'améliorer la robustesse des analyses des signaux EEG, principalement utilisés jusqu'à maintenant dans le domaine du neurofeedback et des ICM, face aux artefacts et au bruit électromagnétique. D'autre part, si l'on s'intéresse au problème de la spécificité fonctionnelle du signal présenté au sujet, des études utilisant l'IRM fonctionnelle ou des techniques de reconstruction de sources à partir du signal EEG, qui fournissent des signaux ayant une meilleure spécificité spatiale, laissent entrevoir de possibles améliorations de la vitesse d'apprentissage. Afin d'augmenter la spécificité spatiale et la contingence fonctionnelle du feedback présenté au sujet, nous avons étudié la stabilité de la décomposition de l'EEG en différentes sources d'activité électrique cérébrale par Analyse en Composantes Indépendantes à travers différentes séances d'enregistrement effectuées sur un même sujet. Nous montrons que ces décompositions sont stables et pourraient permettre d'augmenter la spécificité fonctionnelle de l'entraînement au contrôle de l'activité cérébrale pour l'utilisation d'une ICM. Nous avons également travaillé à l'implémentation d'un outil logiciel permettant l'optimisation des protocoles expérimentaux basés sur le neurofeedback afin d'utiliser ces composantes indépendantes pour rejeter les artefacts en temps réel ou extraire l'activité cérébrale à entraîner. Ces outils sont utiles dans le cadre de l'analyse et de la caractérisation des signaux EEG enregistrés, ainsi que dans l'exploitation de leurs résultats dans le cadre d'un entraînement de neurofeedback. La deuxième partie de ce travail s'intéresse à la mise en place de protocoles de neurofeedback et à l'impact de l'apprentissage. Nous décrivons tout d'abord des résultats obtenus sur une étude pilote qui cherche à évaluer chez des sujets sains l'impact d'un protocole de neurofeedback basé sur le contrôle du rythme Mu. Les changements comportementaux ont été étudiés à l'aide d'un paradigme de signal stop qui permet d'indexer les capacités attentionnelles et d'inhibition de réponse motrice sur lesquelles on s'attend à ce que l'entraînement ICM ait une influence. Pour clore cette partie, nous présentons un nouvel outil interactif immersif pour l'entraînement cérébral, l'enseignement, l'art et le divertissement pouvant servir à évaluer l'impact de l'immersion sur l'apprentissage au cours d'un protocole de neurofeedback. Enfin, les perspectives de l'apport des méthodes et résultats présentés sont discutées dans le contexte du développement des ICMs de nouvelle génération qui prennent en compte la complexité de l'activité cérébrale. Nous présentons les dernières avancées dans l'étude de certains aspects des corrélats neuronaux liés à deux états mentaux ou classes d'états mentaux que l'on pourrait qualifier d'antagonistes par rapport au contrôle de l'attention : la méditation et la dérive attentionnelle, en vue de leur intégration à plus long terme dans un entraînement ICM par neurofeedback.With new technological advances in functional brain imaging and theoretical progress in the knowledge of the different neurophysiologic processes linked to cognition, the last two decades have seen the emergence of Brain-Machine Interfaces (BCIs) allowing a person to observe in real-time, or with a few seconds delay, his own cerebral activity. Clinical domain in general, and more particularly neuropsychology and pathologies leading to heavy motor handicaps, for which potential applications are numerous, whether therapeutic or for functional rehabilitation, has been a major driver of research on this new field of real-time neurosciences. Among these applications, neurofeedback, or neurotherapy, which aims the subject to voluntary control some aspects of his own cerebral activity in order to amplify or reduce them in a therapeutic goal, or for cognitive optimization, represents a promising technique, and an alternative to drug treatments. However, validation of this type of intervention and understanding of involved mechanisms are still in their infancy. Neurofeedback training is often long, up to several weeks. It is therefore very likely that this type of rehabilitation is seeking brain plasticity phenomena that are part of slow dynamics, and thus require a relatively long drive to achieve the desired long-term effects. However, other disturbing elements that could add up to the cause of the difficulty of learning and long training sessions required to achieve the expected results. Among them, the disturbances that come from recorded signal distortions, or artifactual elements that are not part of the signal of interest, are a first potential cause. The lack of functional specificity of the signal returned to the subject could be a second one. We have developed signal processing methodological tools to improve the robustness to artifacts and electromagnetic noise of EEG signals analysis, the main brain imaging technique used so far in the field of neurofeedback and BCIs. On the other hand, if one looks at the issue of functional specificity of the signal presented to the subject, studies using functional MRI or source reconstruction methods from the EEG signal, which both provide signals having a better spatial specificity, suggest improvements to the speed of learning. Seeing Independent Component Analysis as a potential tool to increase the spatial specificity and functional contingency of the feedback signal presented to the subject, we studied the stability of Independent Component Analysis decomposition of the EEG across different recording sessions conducted on the same subjects. We show that these decompositions are stable and could help to increase the functional specificity of BCI training. We also worked on the implementation of a software tool that allows the optimization of experimental protocols based on neurofeedback to use these independent components to reject artifacts or to extract brain activity in real-time. These tools are useful in the analysis and characterization of EEG signals recorded, and in the exploitation of their results as part of a neurofeedback training. The second part focuses on the development of neurofeedback protocols and the impact of learning. We first describe the results of a pilot study which seeks to evaluate the impact of a neurofeedback protocol based on the Mu rhythm control on healthy subjects. The behavioral changes were studied using a stop signal paradigm that indexes the attentional abilities and inhibition of motor responses on which the BCI training can possibly have influence. To conclude this section, we present a new tool for immersive interactive brain training, education, art and entertainment that can be used to assess the impact of immersion on learning during a neurofeedback protocol. Finally, prospects for methods and results presented are discussed in the context of next-generation BCI development which could take brain activity complexity into account. We present the latest advances in the study of certain aspects of the neural correlates associated with two mental states or classes of mental states that could be described as antagonistic with respect to the control of attention: meditation and mind wandering, for their integration in the longer term in an BCI training using neurofeedback
Grands Albums Hachette
No full textSee my earlier version of this book, listed under 1953/66. I ordered this one through eBay because it was listed as published in 1953. I will keep trying for a first edition. Whereas that book was printed in France, this was printed in Italy. Let me repeat my remarks from there: My, Romain Simon illustrated many different books! This is a 28-page oversized (9 x 12½) children's book. There are eleven fables in all, each allotted one to three pages. At least five of them are included somehow in the endpieces at both ends of the book. The stories include GA, FC, FG, LM, TMCM, TH, MM, The Fox and the Goat, WL, FS, and TT. Has the lively, skipping rabbit appeared in Simon's work before? The scarf and shawl on the tortoise make me think I have seen these characters before!This is a hardbound book (hard cover)Language note: FrenchText nach einem Film von Georges de la Grandière; Nacherzählt nach der Fabel von La Fontain
Development of a combined solver to model transport and chemical reactions in catalytic wall-flow filters
Get PDFIn this work, we develop a non-isothermal model for diesel particulate filters including exothermic and competing chemical reactions. We begin with an isothermal, single-reaction model and we gradually increase its complexity. By comparing various models, we aim at establishing the minimum degree of complexity required to effectively model the system under investigation. Based on the numerical simulations, we conclude that isothermal models are adequate only if the temperature of the catalyst is, at all times, completely below or completely above a critical temperature. However, if the goal is to predict the critical temperature, only non-isothermal models should be used. The results with competing reactions, on the other hand, show that the presence of competing reactions does not affect significantly the overall conversion in the filter
Linguistic Innovations In Romain Gary\u27s Creative Laboratory
Get PDFIn this article we study a new background revealed due to Russian translations made by N.Mavlevich in 2015 of the first unpublished novel by Romain Gary, holder of the two Prix Goncourt prizes for his novels The Roots of Heaven (Les Racines du ciel) and The Life Before Us (La vie devant soi) published under the pseudonym Emile Ajar. The empirical writer mentioned about his debut novel in the book The Night is Calm (La nuit sera calme) and his posthumous literary essay The Life and Death of Emil Ajar (Vie et mort d\u27Emile Ajar) thus giving a clue to understanding of his “creative laboratory” related to phenomenal literary mystification. We assume that language experts will be interested in studying of Romain Gary\u27s linguistic biography who created his novels in English and French, considering the fact that Russia was the country where his linguistic development had started. By understanding the role and place of the author\u27s creative laboratory in linguistics we can define relevance and academic novelty of suggested study. The study allows to analyse Romain Gary\u27s creative works from a new perspective and goes beyond the existing method of obtaining knowledge. The main research objects include the author\u27s language and linguistic behaviour of his characters that are featured with well-structured images evoked by Russian words kept in mind from childhood. This system of values is close to the Russian readers and is in tune with the spirit of the modern age. This aspect in the framework of the language-specific nature can be a subject for further research. Linguistic findings made by Romain Gary facilitated the development of the literary language and were focused on increasing of capabilities of the literary speech. Analysis of linguistic innovations in the Romain Gary\u27s creative laboratory allows to receive important information about peculiarities of links between the cognitive and linguistic content discovered in linguistic facts and speech phenomena and make some crucial observations
Portfolio of recorded performances and exegesis: Messiaen’s musical language for the jazz pianist - an exploration through performance.
Get PDFMoving beyond Gunther Schuller’s Third Stream amalgamation of classical and jazz, this study explores whether the musical language of Olivier Messiaen can make a valid contribution to jazz piano performance. Initially, my project sought to answer such questions as: What elements of the musical language of Messiaen already exist in the jazz vocabulary? Am I able to extend this further? What are the timbral structures and pianistic effects within Messiaen’s musical language? What will be the most effective application of Messiaen’s musical language to jazz piano performance? Endeavouring to answer the final question led me to consider such aspects as whether the project should be limited to quoting Messiaen motifs, arranging Messiaen melodies, replacing jazz harmonic structures on standards with examples from Messiaen’s musical language or whether it would be better to approach the research conceptually. The work of Hubert Nuss provided encouraging reassurance that this was not an impossible task. In order to articulate this conception, the initial challenge was to decide how the classical and jazz worlds might meet in a ‘Messiaen’ technique. The approach adopted was similar to that used for undergraduate jazz study, namely, immersion in the piano scores and recordings of Messiaen’s music as well as by live performances. This was followed by the development and assessment of a contrived approach when specific techniques, such as tonal colourings or harmonic structures, were developed through prepared exercises and consciously included in my performance. It was then compared with an intuitive approach when no such precise parameters were established. This submission consists of CD recordings of two public recitals and an exegesis. It documents the development of this Messiaen technique and discusses its application in my performances. It also demonstrates the ways that Messiaen’s musical language can be used within jazz piano performance to provide a colour that distinguishes jazz piano performance in a competitive field.Thesis (M.Mus.) -- University of Adelaide, Elder Conservatorium of Music, 201
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