276 research outputs found
Active Cancellation of TS Instabilities in Compressible Flows Using a Closed-Loop Controller
No full textAbstract only
9 Transcriptomics of Industrial Filamentous Fungi: A New View on Regulation, Physiology, and Application
No full textThe Arab peoples of T.E. Lawrence's Seven Pillars of Wisdom in the light of post-colonial theory
No full textIt can be said that The Seven Pillars of Wisdom is a work whose true potential has not yet been discovered. That the work presents itself to be of greater value than may have previously seemed goes without question. However, during the more than eighty years of its existence, it was the author and not the work that created major interest in the academic world. The complicated character of T.E. Lawrence offered itself to psycho-analyst interpretation and most critiques have been built on these premises. Other works have concentrated on major historical events in Lawrence's life creating thorough biographies and numbers of fascinating approaches, some more, some less misleading were created. However. The Seven Pillars of Wisdom (from henceforth "Seven Pillars") foremostly survived in the shadows of David Lean's film "Lawrence of Arabia" and it was only during the late seventies, that concentration on the Seven Pillars as a text had begun to be cultivated. Additionally, it has only been during the past few years that works by writers such as Gertrude Bell, T.E. Lawrence or Charles M. Doughty have begun to gain a larger public interest. The aim of this work, however, is not to analyse the historical purpose of Lawrence's presence in the Middle East, nor to align the Seven Pillars with historical facts. Such..
The Arab peoples of T.E. Lawrence's Seven Pillars of Wisdom in the light of post-colonial theory
No full textIt can be said that The Seven Pillars of Wisdom is a work whose true potential has not yet been discovered. That the work presents itself to be of greater value than may have previously seemed goes without question. However, during the more than eighty years of its existence, it was the author and not the work that created major interest in the academic world. The complicated character of T.E. Lawrence offered itself to psycho-analyst interpretation and most critiques have been built on these premises. Other works have concentrated on major historical events in Lawrence's life creating thorough biographies and numbers of fascinating approaches, some more, some less misleading were created. However. The Seven Pillars of Wisdom (from henceforth "Seven Pillars") foremostly survived in the shadows of David Lean's film "Lawrence of Arabia" and it was only during the late seventies, that concentration on the Seven Pillars as a text had begun to be cultivated. Additionally, it has only been during the past few years that works by writers such as Gertrude Bell, T.E. Lawrence or Charles M. Doughty have begun to gain a larger public interest. The aim of this work, however, is not to analyse the historical purpose of Lawrence's presence in the Middle East, nor to align the Seven Pillars with historical facts. Such..
Pohled T. E. Lawrence v Sedmi sloupech moudrosti na arabskou populaci ve světle postkoloniální teorie
No full textDalo by se íci, že bylo již napsáno mnohé o spisovateli a dobrodruhovi T. E. Lawrencovi. Ve dvacátém století bylo na nj bohužel nahlíženo jen ve svtle filmu Davida Leana Lawrence z Arábie. Tento film však pinesl zavádjící prvky a pro poznání díla tohoto autora se jeví jako nedostaující. Hlavn z tchto dvod se dílo Seven Pillars of Wisdom (Sedm sloup moudrosti), kterým se zabývám ve své práci dostalo do pozadí dní. Místo díla se stal stedem pozornosti Lawrence sám. Vzniklo tak mnoho spekulací kolem Lawrencovy sexuální orientace a jeho role agenta v tajných službách. To ale není hlavním tématem této práce, ale abychom pohlédli na Lawrence v úplnosti, je zde podkapitola, která odkazuje na patnou literaturu vnující se práv výše zmiované tématice. Snahou je tedy vrátit se k dílu T. E. Lawrence a analyzovat jej podle postkoloniálních teorií. Na poátku je Lawrencv struný životopis. Soustednost je upena jen na nejdležitjší fakta, která jej ovlivnila. Popsaná jsou jeho studentská léta na Oxfordu, jeho následné sobení archeologa na Blízkém Východ, v Egypt a Sýrii a dále setkání s lidmi jako byli David Hogarth i Gertruda Bellová, kteí mli vliv na tvorbu Lawrencových názor na koloniální tematiku. Doba první svtové války s sebou pinesla nové výzvy a Lawrence se stal lenem Intelligence Office v Káhie, kde pedložil svj...It can be said that The Seven Pillars of Wisdom is a work whose true potential has not yet been discovered. That the work presents itself to be of greater value than may have previously seemed goes without question. However, during the more than eighty years of its existence, it was the author and not the work that created major interest in the academic world. The complicated character of T.E. Lawrence offered itself to psycho-analyst interpretation and most critiques have been built on these premises. Other works have concentrated on major historical events in Lawrence's life creating thorough biographies and numbers of fascinating approaches, some more, some less misleading were created. However. The Seven Pillars of Wisdom (from henceforth "Seven Pillars") foremostly survived in the shadows of David Lean's film "Lawrence of Arabia" and it was only during the late seventies, that concentration on the Seven Pillars as a text had begun to be cultivated. Additionally, it has only been during the past few years that works by writers such as Gertrude Bell, T.E. Lawrence or Charles M. Doughty have begun to gain a larger public interest. The aim of this work, however, is not to analyse the historical purpose of Lawrence's presence in the Middle East, nor to align the Seven Pillars with historical facts. Such...Department of Anglophone Literatures and CulturesÚstav anglofonních literatur a kulturFaculty of ArtsFilozofická fakult
Merger Clusters during Economic Booms
No full textMerger activity is intense during economic booms and subdued during recessions. This paper provides a non-financial explanation for this observable pattern. We construct a model in which the target-by setting the takeover price-screens the acquirer on his (expected) ability to realize synergy gains when merging. In an economic boom, it is less profitable to sort out relatively "bad fit" acquirers, leading to a hike in merger activity. Although positive economic shocks produce expected gains at the time of merging, these mergers turn out to be less efficient in the long term-a finding that is broadly consistent with the existing empirical evidence. Furthermore, again because of the absence of boom-time screening, the more efficient acquirers earn higher merger profits during "merger waves" than outside of waves, which is also in line with empirical evidence. ZUSAMMENFASSUNG - (Fusionscluster in Boomphasen) In Zeiten wirtschaftlicher Hochkonjunktur ist die Zahl der Firmenzusammenschlüsse hoch, in Rezessionszeiten eher niedrig. Dieser Aufsatz gibt eine Erklärung für diese Beobachtung, die nicht auf rein finanzwirtschaftlichen Faktoren beruht. Im vorgestellten Modell ha das Unternehmen, welches übernommen wird, die Möglichkeit, den Übernahmepreis festzulegen und kann damit auch die übernehmende Firma auswählen. Das Auswahlkriterium sind die erwarteten Synergiegewinne im Falle einer Fusion, die für eine gute Passung der beiden fusionierenden Unternehmen sprechen. In Phasen der Hochkonjunktur ist es allerdings für Unternehmen generell interessant, zu fusionieren, und es wird relativ weniger profitabel, großen Auswahlaufwand zu treiben, um schlecht passende Fusionspartner auszusortieren und eventuell gar keinen Fusionspartner zu finden. Daher kommt es in diesen Zeiten zu mehr Fusionen als in anderen Konjunkturphasen, die als Fusionswellen bezeichnet werden. Zum Zeitpunkt der Fusion lassen sich auch die erwarteten Gewinne durch die günstige ökonomische Gesamtsituation realisieren. Im weiteren Verlauf stellen sich jedoch solche Fusionen mit schlecht passenden Partnern als wenig effizient heraus-was auch empirische Analysen bestätigt haben. Darüber hinaus zeigt das Modell, dass-wiederum wegen der fehlenden Auswahlprozedur in Boomphasen-die effizienteren Fusionspartner während Fusionswellen höhere Gewinne machen als außerhalb von Fusionswellen. Dies ist zuvor bereits empirisch beobachtet worden.Mergers, Merger Waves, Screening
An unfitted Hybrid High-Order method with cell agglomeration for elliptic interface problems
No full textInternational audienceWe design and analyze a Hybrid High-Order (HHO) method on unfitted meshes to approximate elliptic interface problems by means of a consistent penalty methodà la Nitsche. The curved interface can cut through the mesh cells in a rather general fashion. Robustness with respect to the cuts is achieved by using a cell-agglomeration technique, and robustness with respect to the contrast in the diffusion coefficients is achieved by using a different gradient reconstruction on each side of the interface. A key novel feature of the gradient reconstruction is to incorporate a jump term across the interface, thereby releasing the Nitsche penalty parameter from the constraint of being large enough. Error estimates with optimal convergence rates are established. A robust cell-agglomeration procedure limiting the agglomerations to the nearest neighbors is devised. Numerical simulations for various interface shapes corroborate the theoretical results
The carbon starvation response of Aspergillus niger during submerged cultivation: Insights from the transcriptome and secretome
No full textBackground: Filamentous fungi are confronted with changes and limitations of their carbon source during growth in their natural habitats and during industrial applications. To survive life-threatening starvation conditions, carbon from endogenous resources becomes mobilized to fuel maintenance and self-propagation. Key to understand the underlying cellular processes is the system-wide analysis of fungal starvation responses in a temporal and spatial resolution. The knowledge deduced is important for the development of optimized industrial production processes. Results: This study describes the physiological, morphological and genome-wide transcriptional changes caused by prolonged carbon starvation during submerged batch cultivation of the filamentous fungus Aspergillus niger. Bioreactor cultivation supported highly reproducible growth conditions and monitoring of physiological parameters. Changes in hyphal growth and morphology were analyzed at distinct cultivation phases using automated image analysis. The Affymetrix GeneChip platformwas used to establish genome-wide transcriptional profiles for three selected time points during prolonged carbon starvation. Compared to the exponential growth transcriptome, about 50% (7,292) of all genes displayed differential gene expression during at least one of the starvation time points. Enrichment analysis of Gene Ontology, Pfam domain and KEGG pathway annotations uncovered autophagy and asexual reproduction as major global transcriptional trends. Induced transcription of genes encoding hydrolytic enzymes was accompanied by increased secretion of hydrolases including chitinases, glucanases, proteases and phospholipases as identified by mass spectrometry. Conclusions: This study is the first system-wide analysis of the carbon starvation response in a filamentous fungus. Morphological, transcriptomic and secretomic analyses identified key events important for fungal survival and their chronology. The dataset obtained forms a comprehensive framework for further elucidation of the interrelation and interplay of the individual cellular events involved.Applied Science
Tissue-based proteomics reveals FXYD3, S100A11 and GSTM3 as novel markers for regional lymph node metastasis in colon cancer
No full textRegional lymph node metastasis negatively affects prognosis in colon cancer patients. The molecular processes leading to regional lymph node metastasis are only partially understood and proteomic markers for metastasis are still scarce. Therefore, a tissue-based proteomic approach was undertaken for identifying proteins associated with regional lymph node metastasis. Two complementary tissue-based proteomic methods have been employed. MALDI imaging was used for identifying small proteins (≤25 kDa) in situ and label-free quantitative proteomics was used for identifying larger proteins. A tissue cohort comprising primary colon tumours without metastasis (UICC II, pN0, n = 21) and with lymph node metastasis (UICC III, pN2, n = 33) was analysed. Subsequent validation of identified proteins was done by immunohistochemical staining on an independent tissue cohort consisting of primary colon tumour specimens (n = 168). MALDI imaging yielded ten discriminating m/z species, and label-free quantitative proteomics 28 proteins. Two MALDI imaging-derived candidate proteins (FXYD3 and S100A11) and one from the label-free quantitative proteomics (GSTM3) were validated on the independent tissue cohort. All three markers correlated significantly with regional lymph node metastasis: FXYD3 (p = 0.0110), S100A11 (p = 0.0071), and GSTM3 (p = 0.0173). FXYD3 and S100A11 were more highly expressed in UICC II patient tumour tissues. GSTM3 was more highly expressed in UICC III patient tumour tissues. By our tissue-based proteomic approach, we could identify a large panel of proteins which are associated with regional lymph node metastasis and which have not been described so far. Here we show that novel markers for regional lymph metastasis can be identified by MALDI imaging or label-free quantitative proteomics and subsequently validated on an independent tissue cohort. Copyright © 2012 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd
Isogeometric analysis for thin-walled composite structures
No full textThe conceptual ideas behind isogeometric analysis (IGA) are aimed at unifying computer aided design (CAD) and finite element analysis (FEA). Isogeometric analysis employs the non-uniform rational B-spline functions (NURBS) used for the geometric description of a structure to approximate its physical response in an isoparametric sense. Due to the tensor product property of multi-variate NURBS, it is difficult to represent complex topological shapes with a single NURBS patch. Multiple, often non-conforming patches are needed to tackle increasing complexity of the geometry. To further facilitate the modeling of complex shapes and geometric features trimming technology is widely used in CAD software, however, the trimmed domain is only visually unseen and the trimming features can not be utilized directly for the analysis. To overcome these difficulties, extra efforts are needed to make isogeometric methods adapted to engineering related cases. Thin-walled structures, such as plates and shells, excel in optimal load-carrying behavior and are of major importance in the design of aerospace components and the automotive engineering. Isogeometric analysis is an ideal candidate for the modeling and simulation of shell structures, especially for rotation-free Kirchhoff-Love type shells, which profit from the exact description of the geometry and from the higher continuity properties of NURBS. Furthermore, it favorably supports continuity requirements for flexible through-the-thickness design of laminate composites. Laminated composite materials are increasingly used in the aerospace industry this asks for reliable and computationally efficient lamina theories. The classical lamination theory belongs to the class of equivalent-single-layer methods (ESL), it is computationally efficient but often fails to capture the 3D stress state accurately. The demand for an accurate 3D stress state within laminates is mainly driven by the need to identify and to evaluate potential damage of lamina structures. While a full 3D layerwise (LW) model is computationally expensive, a combined approach considering both concepts, ESL and LW, seems to be a natural choice to tackle the computational costs of increasing model size and model complexity. In this thesis, a layerwise method for laminated composite structures is proposed in the framework of isogeometric analysis. A highly accurate prediction of the state of stress for thick and moderately thick laminate composite shells including transverse normal and shear stresses is demonstrated. The layerwise theory is successfully extended to linear buckling analysis of delaminated composites where a contact formulation is added to eliminate physically inadmissible buckling states which may result from overlapping plies. Furthermore, a Nitsche type formulation is introduced to enforce both weakly, essential boundary conditions and multi-patch coupling constraints for trimmed and non-conforming isogeometric rotation-free Kirchhoff-Love shell patches. The proposed formulation is variationally consistent and excels in a high level of stability and accuracy. A built-in stabilization, used to ensure coercivity of the formulation, prevents ill-conditioning of the physical problem. The inherent trimming problem is tackled with a fictitious domain extension for the trimming domain following the principles of the finite cell method to facilitate the workflow for geometrically complex structures in engineering practice. Computational efficiency is significantly increased with a blended coupling, taking continuum-like shell elements and thin shells elements, according to the theory of Kirchhoff-Love, into account. The blended approach provides access to the full 3D state of stress within selected subdomains while preserving the computational efficiency of the overall analysis.Aerospace Structures and Computational MechanicsAerospace Engineerin
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