Der Geographieunterricht – mehr als Stadt-Land-Fluss?:Eine qualitative Studie zur Relevanz des Schulfaches Geographie aus der Perspektive von Geographielehrerinnen und -lehrern in Nordrhein-Westfalen

Besides their professional knowledge, motivational orientations and self-regulation, teacher’s beliefs constitute a fundamental part of their professional competence and do affect educational practice in the classroom (cf. Reusser et al. 2014; Kunter 2015; Baumert/Kunter 2006; Pajares 1992). Therefore every Geography teacher has own individual beliefs in the form of cognitive schemata , that relate to different items of teaching Geography in addition to the normative, specific requirements of educational standards and the curriculum. In the present qualitative study, which is referring to a survey on the image of Geography (DGFG 2015), Geography teachers of secondary schools in North Rhine-Westphalia have been questioned about their individual beliefs regarding the specific content, competencies, potentials and challenges, as well as ways to support the subject Geography. The main focus was on the question of the special relevance of teaching Geography for the students, the society and the scientific academic discipline.The teacher’s beliefs describe an image of the subject Geography, which is neither conform to the stereotype of “Stadt-Land-Fluss”, nor does it completely correspond to the characteristics of the educational standards and the curriculum. For that reason, the reflection of the distinct individual beliefs, related to teaching Geography, which potentially have influence on how the teachers actually teach Geography, should be considered and promoted in the training of teachers during their studies and later on in advanced trainings to raise the didactical professionalism in teaching, to strengthen the subject Geography itself and to reflectively analyze and modify their own ways of thinking

Effect of the acrylic acid content on the permeability and water uptake of latex films

Acrylic acid (AA) is a monomer commonly employed in emulsion polymerization to provide electrostatic colloidal stability and improve specific film performance. The addition of AA not only modifies the kinetics of the polymerization, but also it takes part in the interaction between colloidal particles, which has a strong influence on their packing and consequent latex film properties. In this contribution a theoretical modeling of the latex film formation is presented and compared to experimental results: water vapor permeability and latex film capacitance are studied as a function of AA content. It has been shown that water uptake is mainly affected by film morphology which in turn is defined by intercolloidal interaction and drying rate.Comment: 16 pages, 7 figure

Isolation and expansion of cytokeratin positive progenitor cells from adult murine pancreatic ducts expressing Pdx-1, Nestin, Sox9, MafA and hepatic nuclear factors

BACKGROUND: Recent studies suggest that stem cells may represent a putative source for the generation of beta cells. However, the identity and characteristics of stem cells from adult pancreas and conditions for their large scale expansion are still poorly defined. METHODS: DPC were isolated from adult pancreatic ducts of C57BI/6 mice. Expression profile was investigated by PCR, FAGS and immunohistochemistry. RESULTS: DPC express a panel of stem cell associated markers such as Pdx-1, cytokeratin-19 (CK19), nestin, Sox9 together with the transcription factor MafA and hepatic nuclear factors HNF1 beta, HNF3 beta, HNF4 alpha and HNF6. This gene expression profile is suggesting that DPC might be a promising tool for endocrine diMrentiation. Atter stimulation with picolinic acid and hypoxia, DPC expressed the endocrine differentiation marker Ngn3. Nevertheless, insulin production was not observed. CONCLUSIONS: We here describe a protocol for the isolation end expansion of murine pancreatic ductal progenitor cells (DPC) displaying high self-renewal, spheroid-and colony-forming capacity. Further studies are required to elucidate the conditions for differentiation into mature pancreatic endocrine cell lineages

Laserbasierte Ultrapraezisionstechnik - 157 nm-Lithographie (157 nm). Teilprojekte: AP 6000: Maskentechnology; AP 7000: Resist- und Waferprozess Abschlussbericht

SIGLEAvailable from TIB Hannover: F02B1250 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung und Forschung, Berlin (Germany); DLR Deutsches Zentrum fuer Luft- und Raumfahrt e.V., Berlin (Germany). Projekttraeger Informationstechnik des BMBFDEGerman

Investigations on the film-formation process of latex dispersions by solid-state NMR spectroscopy

Various latex dispersions based on poly(vinyl acetate) stabilised by different surfactants and polyelectrolytes were investigated by NMR methods to elucidate the macroscopic and molecular film-formation process of these latex dispersions. Macroscopically, the inhomogeneous drying in the film-formation process was investigated by NMR-imaging techniques. Here the influence of different amounts of surfactant on the homogeneity of the drying process was monitored. The molecular film-formation process was investigated by 1H, 2H, and 13C solid state NMR spectroscopy. For these bulk measurements, films of latex dispersions were homogeneously dried to different defined solid contents. Spectroscopic analysis allows the investigation of the drying process of the water at different solid contents with a pronounced influence on the polymer/water interface and the latex particle core. The film-formation process is correlated to the drying mechanism of different types of water within the film. External water, water at ionic and non-ionic groups at surfactants in the polymer/water interface, and water in the swollen and mobilised polymer, could be distinguished during the drying process