112 research outputs found

    Der Einfluss von Testosteron auf die E1S-SulfataseaktivitÀt in nicht-malignen und malignen Brustzellen in vitro

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    Ziel war es, den Effekt von T auf die lokale Östrogensynthese zu messen. Es wurde die Sulfatase (STS) Expression und  AktivitĂ€t in hormonabhĂ€ngigen Brustkrebszellen (BT 474, MCF-7, HBL 100) ermittelt. Die Zellen wurden jeweils mit T inkubiert, und es erfolgte die direkte Messung oder nach 24 Stunden. ZusĂ€tzlich erfolgte die Inkubation der Zellen mit dem Aromataseinhibitor (A) alleine und in Kombination mit T. Die STS-Proteinexpression (dot-blot Analyse der Zelllysate), die STS mRNA Level (quantitative real time PCR) und die STS-AktivitĂ€t (DĂŒnnschichtchromatographie mit radioaktivem markiertem Östronsulfat ([3H] E1S) wurden erfasst. Die STS Proteinexpression war signifikant höher war in den hochmalignen Zellen im Vergleich zu den anderen Zellen.  Innerhalb der Zellreihen gab es keine Unterschiede. UnabhĂ€ngig von der Zelllinie zeigte sich ein Absinken der STS AktivitĂ€t nach direkter und eine Steigerung nach 24 stĂŒndiger Inkubation, was zum Teil durch A abgemildert bzw. umgekehrt wurde. <br

    Inspire: Challenging the lack of interest in physics among students

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    The Inspire project tested and analyzed the use of digital Learning resources (LR) in the field of Maths, Science and Technology (MST) in 63 schools in Austria, Germany, Italy, Lithuania and Spain. MST teachers used the LR from a pool of 60 resources (12 for Physics) in class and the effects on teachers and 5–18+ year old students were measured. We found the use of LR increases the understanding of students of MST and allows for differentiated learning within a class. LR have a larger impact on boys than girls, and it decreases with age. Overall, it appears the use of LR has a positive impact on MST education but special attention has to be placed on technical requirements and localization of the LR

    Non-supersymmetric heterotic model building

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    We investigate orbifold and smooth Calabi-Yau compactifications of the non-supersymmetric heterotic SO(16)xSO(16) string. We focus on such Calabi-Yau backgrounds in order to recycle commonly employed techniques, like index theorems and cohomology theory, to determine both the fermionic and bosonic 4D spectra. We argue that the N=0 theory never leads to tachyons on smooth Calabi-Yaus in the large volume approximation. As twisted tachyons may arise on certain singular orbifolds, we conjecture that such tachyonic states are lifted in the full blow-up. We perform model searches on selected orbifold geometries. In particular, we construct an explicit example of a Standard Model-like theory with three generations and a single Higgs field.Comment: 1+30 pages latex, 11 tables; v2: references and minor revisions added, matches version published in JHE

    Mutations in GDF5 Reveal a Key Residue Mediating BMP Inhibition by NOGGIN

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    Signaling output of bone morphogenetic proteins (BMPs) is determined by two sets of opposing interactions, one with heterotetrameric complexes of cell surface receptors, the other with secreted antagonists that act as ligand traps. We identified two mutations (N445K,T) in patients with multiple synostosis syndrome (SYM1) in the BMP–related ligand GDF5. Functional studies of both mutants in chicken micromass culture demonstrated a gain of function caused by a resistance to the BMP–inhibitor NOGGIN and an altered signaling effect. Residue N445, situated within overlapping receptor and antagonist interfaces, is highly conserved among the BMP family with the exception of BMP9 and BMP10, in which it is substituted with lysine. Like the mutant GDF5, both BMPs are insensitive to NOGGIN and show a high chondrogenic activity. Ectopic expression of BMP9 or the GDF5 mutants resulted in massive induction of cartilage in an in vivo chick model presumably by bypassing the feedback inhibition imposed by endogenous NOGGIN. Swapping residues at the mutation site alone was not sufficient to render Bmp9 NOG-sensitive; however, successive introduction of two additional substitutions imparted high to total sensitivity on customized variants of Bmp9. In conclusion, we show a new mechanism for abnormal joint development that interferes with a naturally occurring regulatory mechanism of BMP signaling

    Developing intermediate cities

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    Intermediate cities have experienced economic dynamism in recent years, but, with the focus firmly on large metropoles and sprawling megacities, the development potential of intermediate cities has stayed out of the limelight. This paper upholds the relevance and potential of intermediate cities, arguing that they can play as important a role – if not a more important one – than the large metropoles that, until now, have been the focus of attention. Intermediate cities hold considerable advantages, in particular for poverty reduction and as more efficient ecosystems to live and work. Untapping the potential of intermediate cities requires, however, more territorially balanced, place-sensitive strategies

    Revisiting Coupling Selection Rules in Heterotic Orbifold Models

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    We study L-point couplings between twisted sector fields in heterotic orbifold compactifications, using conformal field theory. Selection rules provide an easy way to identify which couplings are non-vanishing. Those used in the current literature are gauge invariance, R-charge conservation and the space group selection rule, but they are not the whole story. We revive and refine a fourth selection rule, due to symmetries in the underlying torus lattice, and introduce a fifth one, due to the existence or not of classical worldsheet instanton solutions to mediate the couplings. We consider briefly the phenomenological consequences of the additional rules, in particular for recent orbifold constructions whose field content correspond to that of the MSSM. The structure of the exotic mass matrices is unaltered and many dimension-5 proton-decay operators vanish.Comment: 27 pages, v2: several clarifications, matches JHEP version. v3: supercedes journal version, erratum to appear in JHEP; correction to "rule 5" equations, main ideas unchange

    CAIRT - The changing-atmosphere infra-red tomography explorer

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    Optics InfoBase Conference Papers2021 Article number FTh4G.6. Fourier Transform Spectroscopy, FTS 2021 - Part of OSA Optical Sensors and Sensing Congress 2021Virtual, Online19 July 2021 through 23 July 2021Code 174136CAIRT, a candidate for ESA’s Earth Explorer 11 mission, will observe the Earth’s limb with an imaging Fourier-transform spectrometer. It will provide global observations of ozone, temperature, water vapour and key halogen and nitrogen compounds.With funding from the Spanish government through the Severo Ochoa Centre of Excellence accreditation SEV-2017-0709Peer reviewe

    Determination of nutrient salts by automatic methods both in seawater and brackish water: the phosphate blank

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    9 pĂĄginas, 2 tablas, 2 figurasThe main inconvenience in determining nutrients in seawater by automatic methods is simply solved: the preparation of a suitable blank which corrects the effect of the refractive index change on the recorded signal. Two procedures are proposed, one physical (a simple equation to estimate the effect) and the other chemical (removal of the dissolved phosphorus with ferric hydroxide).Support for this work came from CICYT (MAR88-0245 project) and Conselleria de Pesca de la Xunta de GaliciaPeer reviewe
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