328 research outputs found
Friedrich Heberlein & Wolfgang Slaby, Concordantiae in C. Plinii Caecilii Secundi Opera. Pars Prior. Epistulae. Pars altera. Panegyricus
No full textRaepsaet-Charlier Marie-Thérèse. Friedrich Heberlein & Wolfgang Slaby, Concordantiae in C. Plinii Caecilii Secundi Opera. Pars Prior. Epistulae. Pars altera. Panegyricus. In: L'antiquité classique, Tome 64, 1995. pp. 332-333
Lineage-specific energy and carbon metabolism of sponge symbionts and contributions to the host carbon pool
No full textMarine sponges host a wide diversity of microorganisms, which have versatile modes of carbon and energy metabolism. In this study we describe the major lithoheterotrophic and autotrophic processes in 21 microbial sponge-associated phyla using novel and existing genomic and transcriptomic datasets. We show that the main microbial carbon fixation pathways in sponges are the Calvin–Benson–Bassham cycle (energized by light in Cyanobacteria, by sulfur compounds in two orders of Gammaproteobacteria, and by a wide range of compounds in filamentous Tectomicrobia), the reductive tricarboxylic acid cycle (used by Nitrospirota), and the 3-hydroxypropionate/4-hydroxybutyrate cycle (active in Thaumarchaeota). Further, we observed that some sponge symbionts, in particular Acidobacteria, are capable of assimilating carbon through anaplerotic processes. The lithoheterotrophic lifestyle was widespread and CO oxidation is the main energy source for sponge lithoheterotrophs. We also suggest that the molybdenum-binding subunit of dehydrogenase (encoded by coxL) likely evolved to benefit also organoheterotrophs that utilize various organic substrates. Genomic potential does not necessarily inform on actual contribution of autotrophs to light and dark carbon budgets. Radioisotope assays highlight variability in the relative contributions of photo- and chemoautotrophs to the total carbon pool across different sponge species, emphasizing the importance of validating genomic potential with physiology experimentation
MiR-4646-5p Acts as a Tumor-Suppressive Factor in Triple Negative Breast Cancer and Targets the Cholesterol Transport Protein GRAMD1B
No full textMicroRNAs (miRNAs) are crucial post-transcriptional regulators of gene expression, and their deregulation contributes to many aspects of cancer development and progression. Thus, miRNAs provide insight into oncogenic mechanisms and represent promising targets for new therapeutic approaches. A type of cancer that is still in urgent need of improved treatment options is triple negative breast cancer (TNBC). Therefore, we aimed to characterize a novel miRNA with a potential role in TNBC. Based on a previous study, we selected miR-4646-5p, a miRNA with a still unknown function in breast cancer. We discovered that higher expression of miR-4646-5p in TNBC patients is associated with better survival. In vitro assays showed that miR-4646-5p overexpression reduces growth, proliferation, and migration of TNBC cell lines, whereas inhibition had the opposite effect. Furthermore, we found that miR-4646-5p inhibits the tube formation ability of endothelial cells, which may indicate anti-angiogenic properties. By whole transcriptome analysis, we not only observed that miR-4646-5p downregulates many oncogenic factors, like tumor-promoting cytokines and migration- and invasion-related genes, but were also able to identify a direct target, the GRAM domain-containing protein 1B (GRAMD1B). GRAMD1B is involved in cellular cholesterol transport and its knockdown phenocopied the growth-reducing effects of miR-4646-5p. We thus conclude that GRAMD1B may partly contribute to the diverse tumor-suppressive effects of miR-4646-5p in TNBC
Macrophages Interaction and MicroRNA Interplay in the Modulation of Cancer Development and Metastasis
No full textAdvancement in cancer research has shown that the tumor microenvironment plays a crucial role in the installation, progression, and dissemination of cancer cells. Among the heterogeneous panel of cells within the malignant microenvironment are tumor-associated macrophages that are sustaining the malignant cells through strict feedback mechanisms and spatial distribution. Considering that the presence of metastasis is one of the main feature associated with decreased survival rates among patients, in the present article we briefly present the involvement of tumor-associated macrophages in the hallmarks of metastasis and their microRNA-related regulation with a focus on lung cancer in order to coordinate the vast information under one pathology. As shown, these cells have emerged as coordinators of immunosuppression, angiogenesis and lymphangiogenesis, vessel intravasation and extravasation of cancer cells, and premetastatic niche formation, transforming the macrophages in potential therapeutic targets and also prognostic markers according to their density within the tumor and polarization phenotype. An indirect therapeutic approach on tumor-associated macrophages can be also represented by regulation of microRNAs involved in their polarization and implicit oncogenic features. Examples of these microRNAs consist in the highly studied miR-21 and miR-155, but also other microRNA with less feedback in the literature: miR-1207-5p, miR-193b, miR-320a, and others
K-feldspar phenocrysts in microgranular magmatic enclaves: A cathodoluminescence and geochemical study of crystal growth as a marker of magma mingling dynamics
No full textThe crystallization history of zoned K-feldspar phenocrysts in microgranular magmatic enclaves in the Karkonosze granite (SW Poland) reveals that the crystals grew in stirred coeval magmas of contrasting compositions. The growth mechanism and crystal compositions are investigated using cathodoluminescence and profiling by Electron Microprobe and Laser Ablation ICP-MS. These methods provide insight into the crystallization process and the varying compositions of the host melt. The phenocrysts show two types of growth patterns - with or without resorption interfaces. The trace-element distribution, heterogeneous across different zones and within single phenocryst zones, reflects a dynamic process of crystal growth from compositionally heterogeneous magma. Hybridization is also reflected in the density of structural Al-O--Al defects - features that relate to coupled Ba-Al incorporation into the crystal structure. Differences in structural-defect densities and crystal composition trace the degree of hybridization in the granitic magma during the growth of the K-feldspar phenocrysts. (C) 2008 Elsevier B.V. All rights reserved.[BW 1642]; [BST 1241/8]; [NN307176633
« Vos pensées ne sont pas mes pensées et mes chemins ne sont pas vos chemins » (Isaïe 55.8) : une réflexion sur le thème de l’ordre dans les Suspiria de Profundis (1845) de Thomas De Quincey
No full textThis article looks at the theme of order in Thomas De Quincey’s Suspiria de Profundis (1845). Although chaos is easily noticeable in De Quincey’s digressional style, order is also a recurring motif in the narrative of this mature work. Indeed, for the Protestant and Romantic author plagued by suffering, chaos and order are the starting points for broader reflections. De Quincey discovers that chaos in the outer and inner worlds is but apparent, and that deciphering these worlds enables him to see a unifying or organizing force beneath contraries and paradoxes. As a consequence, in his hermeneutics based on the scandal of suffering, De Quincey introduces the notion of obliqueness operating through the masks behind which God acts, thus retracing the very paths taken by God and disclosing his own theology
Gyro-kinetic simulations of tokamaks and stellarators including collisions
No full textThis dissertation focusses on the numerical modelling of resonant destabilization of Alfvén eigenmodes by fast ions in fusion plasmas. It especially addresses non-linear simulations of stellarator plasmas in which particle collisions are retained. It is shown that collisions are required for a realistic description of Alfvén waves in plasmas relevant to nuclear fusion.
We start by carefully verifying the implementation of the collision operators into the electromagnetic version of the gyro-kinetic delta-f particle-in-cell code EUTERPE. After these initial benchmarks are completed successfully, the code is in a position to be applied to realistic tokamak and stellarator scenarios.
Since every collision operator needs to fulfil conservation laws, a momentum-conserving version of the pitch-angle scattering operator is implemented. This is in particular important for neoclassical transport simulations aimed at computing flux-surface variations of the electrostatic potential in stellarators.
Using the simplified CKA-EUTERPE model (employing a fixed-mode-structure approximation), we perform non-linear simulations in tokamaks and stellarators. We show that the non-linear dynamics of fast-ion-driven Alfvén eigenmodes is significantly influenced by collisions. They have the potential to enhance the saturation level and to affect the frequency chirping of the modes.
It is thus concluded that collisions play an essential role in determining Alfvén-eigenmode-induced fast-ion transport - an important issue for future fusion devices. In order to address this issue the CKA-EUTERPE model is extended to evolve multiple modes at the same time. First results of this multi-mode version (which enhances the level of realism of the simulations) are shown in the Appendix of the thesis.Diese Dissertation befasst sich mit numerischen Simulationen der resonanten Anregung von Alfvén Eigenmoden durch schnelle Ionen in Fusionsplasmen. Der Fokus liegt hierbei auf nichtlinearen Simulationen von Stellaratorplasmen, wobei Teilchenstöße berücksichtigt werden. Wir zeigen, dass für die realistische Beschreibung von Alfvén Wellen in Fusionsplasmen Stöße beachtet werden müssen.
Wir starten damit, die Implementation der Stoßoperatoren in den gyro-kinetischen delta-f Teilchencode EUTERPE sorgfältig zu verifizieren. Nach dem erfolgreichen Abschluss dieser Benchmarks, kann der Code auf realistische Tokamak- und Stellaratorszenarien angewandt werden.
Da jeder Stoßoperator Erhaltungssätze erfüllen muss, haben wir eine impulserhaltende Version des Pitchwinkelstoßoperators implementiert. Dies ist insbesondere wichtig für Simulationen des neoklassischen Transports, die genutzt werden, um Variationen des elektrostatischen Potentials auf Flussflächen in Stellaratoren zu bestimmen.
Unter Benutzung des vereinfachten CKA-EUTERPE Modells (welches die Näherung verwendet, dass die Modenstruktur unveränderbar ist), haben wir nichtlineare Simulationen in Tokamaks und Stellaratoren durchgeführt. Wir zeigen, dass die nichtlineare Dynamik der Alfvén Eigenmoden, angeregt durch schnelle Ionen, signifikant durch Stöße beeinflusst wird. Stöße haben hierbei das Potential das Saturierungslevel zu erhöhen, sowie das Frequenzchirping der Moden zu beeinflussen.
Wir schließen daraus, dass Stöße eine wichtige Rolle für den Transport von schnellen Ionen, ausgelöst durch die Anwesenheit der Alfvén Eigenmoden, spielen. Dies ist ein wichtiger Aspekt zukünftiger Fusionsreaktoren. Um dieses Thema anzugehen, wird das CKA-EUTERPE Modell dahingehend weiterentwickelt, dass mehrere Moden simultan simuliert werden können. Erste Ergebnisse dieser Multi-Moden Version (welche den Realismus der Simulationen steigert) werden im Anhang der Arbeit gezeigt
MiR-4649-5p acts as a tumor-suppressive microRNA in triple negative breast cancer by direct interaction with PIP5K1C, thereby potentiating growth-inhibitory effects of the AKT inhibitor capivasertib
No full textBackground: Triple negative breast cancer (TNBC) is a particularly aggressive and difficult-to-treat subtype of breast cancer that requires the development of novel therapeutic strategies. To pave the way for such developments it is essential to characterize new molecular players in TNBC. MicroRNAs (miRNAs) constitute interesting candidates in this regard as they are frequently deregulated in cancer and contribute to numerous aspects of carcinogenesis. Methods and results: Here, we discovered that miR-4649-5p, a miRNA yet uncharacterized in breast cancer, is associated with better overall survival of TNBC patients. Ectopic upregulation of the otherwise very low endogenous expression levels of miR-4646-5p significantly decreased the growth, proliferation, and migration of TNBC cells. By performing whole transcriptome analysis and physical interaction assays, we were able to identify the phosphatidylinositol phosphate kinase PIP5K1C as a direct target of miR-4649-5p. Downregulation or pharmacologic inhibition of PIP5K1C phenocopied the growth-reducing effects of miR-4649-5p. PIP5K1C is known to play an important role in migration and cell adhesion, and we could furthermore confirm its impact on downstream PI3K/AKT signaling. Combinations of miR-4649-5p upregulation and PIP5K1C or AKT inhibition, using the pharmacologic inhibitors UNC3230 and capivasertib, respectively, showed additive growth-reducing effects in TNBC cells. Conclusion: In summary, miR-4649-5p exerts broad tumor-suppressive effects in TNBC and shows potential for combined therapeutic approaches targeting the PIP5K1C/PI3K/AKT signaling axis
Magma generation in an alternating transtensional–transpressional regime, the Kraków–Lubliniec Fault Zone, Poland
No full textIn the Krakow-Lubliniec Fault Zone (KLFZ) late Carbonifereous-Permian volcanic rocks mark the boundary between the Malopolska Block (thinned marginal sector of Baltica) and the Upper Silesian Block (a sector of the Brunovistulia composite Terrane). The Zone is a part of the major Hamburg-Krakow-Dobrogea transcontinental strike-slip tectonic zone separating the Laurussian craton and Gondwana blocks which came together to form it. The geochemistry of the volcanic rocks reflects the collisional nature of the tectonism. However, it also presents a signature compatible with extensional magmatism. The paper presents models of magma generation and evolution in what was a zone of alternating transpression and transtension. The magmatism in this zone of amalgamated terranes was related to two different sources: enriched mantle and primitive crust. The lithospheric mantle beneath some blocks of the amalgamated terranes may have experienced enrichment processes during previous subduction events. The metasomatism may have also occurred as a result of crustal thickening during transpression followed by delamination, subsidence and melting. These metasomatised blocks reacted with decompressional melting. Our results show that magma generation and evolution in the zone seem to be not typical examples of late Carbonifereous-Permian magmatism, which is known from other locations throughout Central Europe. (C) 2010 Elsevier B.V. All rights reserved
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