17 research outputs found

    Wet-Chemically Prepared Porphyrin Layers on Rutile TiO2(110)

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    Porphyrins are large organic molecules that are interesting for different applications, such as photovoltaic cells, gas sensors, or in catalysis. For many of these applications, the interactions between adsorbed molecules and surfaces play a crucial role. Studies of porphyrins on surfaces typically fall into one of two groups: (1) evaporation onto well-defined single-crystal surfaces under well-controlled ultrahigh vacuum conditions or (2) more application-oriented wet chemical deposition onto less well-defined high surface area surfaces under ambient conditions. In this study, we will investigate the wet chemical deposition of 5-(monocarboxyphenyl)-10,15,20-triphenylporphyrin (MCTPP) on well-defined rutile TiO2 (110) single crystals under ambient conditions. Prior to deposition, the TiO2(110) crystals were also cleaned wet-chemically under ambient conditions, meaning none of the preparation steps were done in ultrahigh vacuum. However, after each preparation step, the surfaces were characterized in ultrahigh vacuum with X-ray photoelectron spectroscopy (XPS) and the result was compared with porphyrin layers prepared in ultrahigh vacuum (UHV) by evaporation. The differences of both preparations when exposed to zinc ion solutions will also be discussed.Fil: Wechsler, Daniel. Universitat Erlangen-Nuremberg; AlemaniaFil: Fernández, Cynthia Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; ArgentinaFil: Köbl, Julia. Universitat Erlangen-Nuremberg; AlemaniaFil: Augustin, Lisa Marie. Universitat Erlangen-Nuremberg; AlemaniaFil: Stumm, Corina. Universitat Erlangen-Nuremberg; AlemaniaFil: Norbert Jux. Universitat Erlangen-Nuremberg; AlemaniaFil: Steinruck, Hans Peter. Universitat Erlangen-Nuremberg; AlemaniaFil: Williams, Federico José. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; ArgentinaFil: Lytken, Ole. Universitat Erlangen-Nuremberg; Alemani

    Fast Growth Increases the Selective Advantage of a Mutation Arising Recurrently during Evolution under Metal Limitation

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    Understanding the evolution of biological systems requires untangling the molecular mechanisms that connect genetic and environmental variations to their physiological consequences. Metal limitation across many environments, ranging from pathogens in the human body to phytoplankton in the oceans, imposes strong selection for improved metal acquisition systems. In this study, we uncovered the genetic and physiological basis of adaptation to metal limitation using experimental populations of Methylobacterium extorquens AM1 evolved in metal-deficient growth media. We identified a transposition mutation arising recurrently in 30 of 32 independent populations that utilized methanol as a carbon source, but not in any of the 8 that utilized only succinate. These parallel insertion events increased expression of a novel transporter system that enhanced cobalt uptake. Such ability ensured the production of vitamin B12, a cobalt-containing cofactor, to sustain two vitamin B12–dependent enzymatic reactions essential to methanol, but not succinate, metabolism. Interestingly, this mutation provided higher selective advantages under genetic backgrounds or incubation temperatures that permit faster growth, indicating growth-rate–dependent epistatic and genotype-by-environment interactions. Our results link beneficial mutations emerging in a metal-limiting environment to their physiological basis in carbon metabolism, suggest that certain molecular features may promote the emergence of parallel mutations, and indicate that the selective advantages of some mutations depend generically upon changes in growth rate that can stem from either genetic or environmental influences

    Predictors of Literacy and Attitudes Toward Reading Among Syrian Refugee Children in Jordan

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    Refugee children often face disruptions to their education before and during displacement. However, little is known about either levels or predictors of refugee children’s literacy or about their attitudes toward reading in low- or middle-income countries. To address this, we conducted in-home literacy assessments using the Holistic Assessment of Learning and Development Outcomes with 322 Syrian refugee mother–child dyads who lived in Jordan (child age range 4–8 years, M = 6.32 years, 50% female). Overall, the children had quite low levels of literacy, although they indicated a strong enthusiasm for reading. Child age, maternal education, and maternal ability to read all predicted child literacy, although maternal literacy predicted it only among children enrolled in school. Among those enrolled in school (64.9% of the total sample, 88.7% of those aged ≥ 6), students attending hybrid classes had better literacy than those attending either solely in-person or solely online, although the frequency of school attendance did not predict literacy. A less consistent pattern emerged for predicting children’s attitudes toward reading. Our results suggest an urgent need to improve literacy skills among refugee children in Jordan, as well as a need for validated measures of attitudes toward reading for use with Arabic-speaking youth

    Small Supernumerary Marker Chromosomes 1 With a Normal Phenotype

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    Small supernumerary marker chromosomes (sSMCs) are a major problem in prenatal cytogenetic diagnostics. Over two-thirds of cases carrying an sSMC derived from chromosome 1 are associated with clinical abnormalities. We report 3 further cases of such sSMCs that did not show any clinical abnormalities. All 3 sSMCs studied were detected prenatally and characterized comprehensively for their genetic content by molecular cytogenetics using subcentromere-specific multicolor fluorescence in situ hybridization, and for a possibly associated uniparental disomy. After exclusion of additional euchromatin due to the presence of sSMCs and a uniparental disomy, parents opted for continuation of the pregnancies and healthy children were born in all 3 cases. It is important to quickly and clearly characterize prenatal sSMCs. Also, all available sSMC cases need to be collected on a homepage such as the Jena Institute of Human Genetics and Anthropology sSMC homepage (http://www.med.uni-jena.de/fish/sSMC/00START.htm)

    TAK1 and IKK2, novel mediators of SCF-induced signaling and potential targets for c-Kit-driven diseases

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    NF-κB activation depends on the IKK complex consisting of the catalytically active IKK1 and 2 subunits and the scaffold protein NEMO. Hitherto, IKK2 activation has always been associated with IκBα degradation, NF-κB activation, and cytokine production. In contrast, we found that in SCF-stimulated primary bone marrow-derived mast cells (BMMCs), IKK2 is alternatively activated. Mechanistically, activated TAK1 mediates the association between c-Kit and IKK2 and therefore facilitates the Lyn-dependent IKK2 activation which suffices to mediate mitogenic signaling but, surprisingly, does not result in NF-κB activation. Moreover, the c-Kit-mediated and Lyn-dependent IKK2 activation is targeted by MyD88-dependent pathways leading to enhanced IKK2 activation and therefore to potentiated effector functions. In neoplastic cells, expressing constitutively active c-Kit mutants, activated TAK1 and IKKs do also not induce NF-κB activation but mediate uncontrolled proliferation, resistance to apoptosis and enables IL-33 to mediate c-Kit-dependent signaling. Together, we identified the formation of the c-Kit-Lyn-TAK1 signalosome which mediates IKK2 activation. Unexpectedly, this IKK activation is uncoupled from the NF-κB-machinery but is critical to modulate functional cell responses in primary-, and mediates uncontrolled proliferation and survival of tumor-mast cells. Therefore, targeting TAK1 and IKKs might be a novel approach to treat c-Kit-driven diseases

    Ăśberbau : Relations of production in architecture in the Anthropocene

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    Gedruckt erschienen im Universitätsverlag der TU Berlin, ISBN 978-3-7983-3213-3Wo werden die Rohstoffe für die fortschrittverheißenden architektonischen und infrastrukturellen Großprojekte in Stahl und Beton abgebaut? Wie ist Architektur mit dem globalen System der Lieferketten verstrickt? Wer profitiert von der Verteilung von Grund und Boden? Welche Arbeits- bedingungen herrschen auf europäischen Großbaustellen? Und in bundesrepublikanischen Architekturbüros? Wie wird Architektur heute produziert? Die Publikation handelt von Umweltzerstörung und Land Grabbing der Zementindustrie in Indonesien und Vietnam, den Methoden der Sandmafia am Mekong, und die Extrakti- on von Lithium in Bolivien für die Batterien unserer Smart Cities. Sie beleuchtet strukturelle bodenpolitische Ungleich- heiten und die prekären Anstellungsverhältnisse jener Ar- chitekturmachender, die bei der Betrachtung spektakulärer Neubauten zumeist vergessen werden. So werden die For- men architektonischer Gouvernementalität greifbar.Where do the raw materials for the large-scale and process-promissing architectural and infrastructural projects in steel and concrete come from? How is architecture entangled with the global system of supply chains? Who benefits from the distribution of property? What are the working conditions on major European construction sites? And in German architectural offices? How is architecture produced today? The publication deals with environmental destruction and land grabbing by the cement industry in Indonesia and Vietnam, the methods of the sand mafia on the Mekong, and the extraction of lithium in Bolivia for the batteries of our smart cities. It sheds light on structural inequalities in land policy and the precarious employment conditions of those who make architecture, who are usually forgotten in the contemplation of spectacular new buildings. In this way, the forms of architectural governmentality become tangible
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