Au carrefour des disciplines, au détour des terrains: dialogues, échanges et nouvelles convivialités épistémologiques

Presentation (2015, December 04)

DIFFERENTIAL EFFECTS OF IL-6-TYPE CYTOKINES, THEIR INTERPLAY WITH HYPOXIA AND RESULTING EFFECTS ON THE METABOLISM

Doctoral thesis (2015)

IL-6-type cytokines signal mainly via the Jak/STAT pathway using the common receptor chain gp130. They are implicated in various biological processes such as differentiation, apoptosis, tissue ... [more ▼]

IL-6-type cytokines signal mainly via the Jak/STAT pathway using the common receptor chain gp130. They are implicated in various biological processes such as differentiation, apoptosis, tissue regeneration and proliferation. However, one of their main functions is the regulation of inflammatory processes, especially the initial induction of an inflammatory response. They hereby exert key steps in the onset as well as in the termination of an inflammation and in the promotion of the shift from the innate to the adaptive immune response. In hepatocellular carcinoma (HCC) IL-6 has been identified as a key factor in the onset as well as in the progression of this cancer. In this study we first investigated the effects of the IL-6-type cytokine IL-27 on hepatic cells. By evaluating IL-27 signalling in several HCC cell lines as well as hepatic cells, we could demonstrate that IL-27 does, in contrary to other IL-6-type cytokines, activate STAT1 and STAT3. A transcriptional and protein read-out of STAT3 was not found in hepatic cells. Thus, IL-27 exerts interferon γ-like functions only in the liver. Interestingly, we could further show that the IL-27 signalling can still be repressed by the canonical IL-6-type cytokine feedback regulator SOCS3, following a pre-stimulation with other IL-6-type cytokines. The second part of this thesis focused on the effects of the IL-6-type cytokine Oncostatin M (OSM) on the cellular metabolism. We hereby evaluated to which extent OSM-mediated STAT3 activation can induce a Warburg-like, highly glycolytic, metabolic phenotype under normoxia. OSM induced the expression of HIF-1α, a key factor mediating the shift to a highly glycolytic phenotype, in several HCC cell lines and immortalized hepatocytes. In the non-neoplastic hepatocyte cell line, PH5CH8, this led to the induction of a more glycolytic metabolic phenotype. The observed changes in these immortalized hepatocytes did not fully resemble the metabolic state seen under hypoxia, since mainly the observed induction of PDK1 seems to explain the effect. Overall we could not observe strong effects on glycolytic enzymes or other canonical HIF-1α target genes involved in metabolism, on a transcriptional or protein expression level in the investigated cells. Interestingly we found that HIF-1α does not seem to be mediating all the early adaptions of the cellular metabolism to hypoxia. The early inhibition of the pyruvate dehydrogenase complex could be shown to be independent of the HIF-1α-mediated up-regulation of the pyruvate dehydrogenase kinase 1, but might rather be induced by reactive oxygen species, created during the switch from normoxia to hypoxia. In summary we could show that in the liver IL-27 exerts interferon γ-like effects. Additionally, cytokine-activated STAT3 does not per se induce a glycolytic metabolic phenotype and HIF-1α is not necessary for some of the early adaptions of the cellular metabolism to hypoxia. [less ▲]

Fundamentals and advances in magnetic hyperthermia

in Applied Physics Reviews (2015), 2

Vibrational and optical properties of MoS2: From monolayer to bulk

in Surface Science Reports (2015), 70(4), 554-586

Molybdenum disulfide, MoS2, has recently gained considerable attention as a layered material where neighboring layers are only weakly interacting and can easily slide against each other. Therefore ... [more ▼]

Molybdenum disulfide, MoS2, has recently gained considerable attention as a layered material where neighboring layers are only weakly interacting and can easily slide against each other. Therefore, mechanical exfoliation allows the fabrication of single and multi-layers and opens the possibility to generate atomically thin crystals with outstanding properties. In contrast to graphene, it has an optical gap of ~1.9 eV. This makes it a prominent candidate for transistor and opto-electronic applications. Single-layer MoS2 exhibits remarkably different physical properties compared to bulk MoS2 due to the absence of interlayer hybridization. For instance, while the band gap of bulk and multi-layer MoS2 is indirect, it becomes direct with decreasing number of layers. In this review, we analyze from a theoretical point of view the electronic, optical, and vibrational properties of single-layer, few-layer and bulk MoS2. In particular, we focus on the effects of spin–orbit interaction, number of layers, and applied tensile strain on the vibrational and optical properties. We examine the results obtained by different methodologies, mainly ab initio approaches. We also discuss which approximations are suitable for MoS2 and layered materials. The effect of external strain on the band gap of single-layer MoS2 and the crossover from indirect to direct band gap is investigated. We analyze the excitonic effects on the absorption spectra. The main features, such as the double peak at the absorption threshold and the high-energy exciton are presented. Furthermore, we report on the the phonon dispersion relations of single-layer, few-layer and bulk MoS2. Based on the latter, we explain the behavior of the Raman-active A1gA1g and View the MathML sourceE2g1 modes as a function of the number of layers. Finally, we compare theoretical and experimental results of Raman, photoluminescence, and optical-absorption spectroscopy. [less ▲]

The clash of European concepts regarding central bank independence: The Franco-Germanic (“Latin-Teutonic”) dispute on the ECB’s role during the euro crisis

in Milenkovic, Marko (Ed.) European Union and Legal Reform 2013 (2015)

The global financial crisis – which, in the European Union, has further transformed into the EU sovereign debt crisis (the euro crisis) – has shaken the foundations of the Economic and Monetary Union as ... [more ▼]

The global financial crisis – which, in the European Union, has further transformed into the EU sovereign debt crisis (the euro crisis) – has shaken the foundations of the Economic and Monetary Union as established in 1992, particularly regarding the stabilising role of the European Central Bank (ECB). As a result, two blocks of countries emerged: the first consisted of the northern eurozone countries (less affected by the crisis), which advocated for strict ECB independence and the continuation of its limited price stability mandate (“the Teutonic block”); the second included the southern eurozone countries, which suffered great difficulties in acquiring financing for their public debts and called for the ECB to take a more politically active role. This paper argues that such contradictory approaches are inevitable in a heterogeneous entity like the European Union (specifically, the eurozone) and need not necessarily undermine the future of the eurozone as a whole. Indeed, the 50 years of European integration led by the Franco-Germanic engine indicate that such different standpoints are nothing extraordinary. The remaining challenge is to transform them into ‘productive tension’ to keep the European project on the move. [less ▲]

A Class of Improved Wake Interaction Model for the Coordinated Control of Wind Farms

in IEEE Conference Publications (Ed.) IEEE International Chinese Automation Congress (CAC), 2015 (2015, December 01)

This paper is focused on the Wind Energy (WE) systems and Wind Farms (WFs) optimization in Luxembourg. It describes the overview of the wind resources in all the WFs and presents a class of Improved Wake ... [more ▼]

This paper is focused on the Wind Energy (WE) systems and Wind Farms (WFs) optimization in Luxembourg. It describes the overview of the wind resources in all the WFs and presents a class of Improved Wake Interaction Model (IWIM) for Coordination and Optimization Control (CnOC) of WFs. Based on Wind Power (WP) assessment of WFs, the statistical method is used to model the distribution of Wind Speed (WS) and Wind Direction (WD). Some simulation figures about the Wind Rose (WR) and WF optimization demonstrate the description and assessment of WP in detail. These assessments are expected to enhance the effectiveness of exploitation and utilization of WP in WFs of Luxembourg. [less ▲]

‘La Grande Guerre et ses chansons.’ „La chanson de Craonne“ und „Quand Madelon“ als Spiegelbilder einer Nation im Krieg

in Militärmusik im Diskurs (2015), 9

Early-Stage Assessment for Office Buildings concerning thermal comfort , energy efficiency amd sustainabilty

in 14th International Building Simulation Conference BS 2015 (2015, December)

The building facade greatly influences energy demand, internal comfort and environmental quality of office buildings. This paper shows the influence of relevant design parameters for highly glazed systems ... [more ▼]

The building facade greatly influences energy demand, internal comfort and environmental quality of office buildings. This paper shows the influence of relevant design parameters for highly glazed systems. In detail constructive and technical measures have been evalutated to optimise light weight composite and solid structures in European climate. The structure type and the glazing share indeed have some influence on the energetic and thermal behaviour of the building but the influence of the ventilation strategy is significantly higher. However, in case of an adequate ventilation strategy, the structure type becomes more decisive if a thermal optimisation, especially a reduction of the over-heating risk, shall be achieved. [less ▲]

Avant-propos. Habiter l’espace post-yougoslave

in Revue d'Etudes Comparatives Est-Ouest (2015), 46(4), 7-34

Folk music: Luxembourg

in Leerssen, Joep (Ed.) Encyclopedia of Romantic Nationalism in Europe (2015)

FULL TEXT The first folksong collection in Luxembourg, Die luxemburger Volkslieder älterer Zeit, compiled by the folklorist and ethnologist Edmond de la Fontaine (alias Dicks, 1823-1891), was published ... [more ▼]

FULL TEXT The first folksong collection in Luxembourg, Die luxemburger Volkslieder älterer Zeit, compiled by the folklorist and ethnologist Edmond de la Fontaine (alias Dicks, 1823-1891), was published posthumously in 1904. It contains only forty songs, and due to the unscientific way they had been collected, some important information is missing; nonetheless it offers a first glipse into folksongs in 19th-century Luxembourg. Their lyrics were adapted to the Luxembourg context, although only a few songs originate from the country. A scholarly, methodical folksong collection following the model of Erk and Böhme’s Deutscher Liederhort (1893-94) was published in 1937, entitled Singendes Volk. Its author, Mattias Thill, a primary school teacher, spent about four decades collecting songs throughout the Grand Duchy; again, most songs are variants of existing songs of non-Luxembourgish origin, 65% from Germany and a mere 3% from France. The remaining 32% have Luxembourgish texts (which, again, speaks for their more complete integration into Luxembourg life, not necessarily for a Luxembourg origin). Indigenous songs are often related to the military history and to the fortress of Luxembourg. Folk music in Luxembourg is predominantly vocal, with the one curious exception of a mystical blind violin-playing minstrel, Matthias Schou (alias Blannen Theis, 1747-1824) who was led from parish fair to parish fair by his wife and entertained the peasant population with his songs. Until today no sources have been discovered, but it is assumed that this troubadour is at the origin of melodies gathered a century later. In three cases, songs were subsequently arranged to instrumental music at a later date and gained a persistent performative presence to the point of becoming markers of Luxembourgish musical identity: the Wilhelmus, the Song of the dancing Procession, and the Hämmelsmarsch The Wilhelmus is the anthem of the Grand-Ducal court (not of the country), and is performed at the occasion of an official appearance of the Grand-Duke or of a member of his family. The melody is a variant of the Dutch national anthem Wilhelmus van Nassouwe, evidently based on Mozart’s Seven variations on Wilem Van Nassau (1766, KV 25) The “Song of the Dancing Procession” originates from the famous Procession of Echternach, and is based on the German folksong Adam hatte sieben Söhn’, arranged to a Rheinländerpolka for wind band in a medium tempo suitable for pilgrims taking three steps forward and two steps backwards. The Hämmelsmarsch, a beggar song derived from a 14th-century shepherd’s fair song, was played by pipers and drummers while visitors had to pay a fee. Modern-day local wind bands maintain this tradition, strolling the streets during parish fairs and requesting financial donations while playing this song. [less ▲]