@article{ScholzSauerWiessneretal.2013, author = {Scholz, M. and Sauer, C. and Wiessner, M. and Nguyen, N. and Scholl, A. and Reinert, F.}, title = {Structure formation in organic thin films observed in real time by energy dispersive near-edge x-ray absorption fine-structure spectroscopy}, series = {New Journal of Physics}, volume = {15}, journal = {New Journal of Physics}, number = {083052}, doi = {10.1088/1367-2630/15/8/083052}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-129749}, year = {2013}, abstract = {We study the structure formation of 1,4,5,8-naphthalenetetracarboxylicacid- dianhydride (NTCDA) multilayer films on Ag(111) surfaces by energy dispersive near-edge x-ray absorption fine-structure spectroscopy (NEXAFS) and photoelectron spectroscopy. The time resolution of seconds of the method allows us to identify several sub-processes, which occur during the post-growth three-dimensional structural ordering, as well as their characteristic time scales. After deposition at low temperature the NTCDA molecules are preferentially flat lying and the films exhibit no long-range order. Upon annealing the molecules flip into an upright orientation followed by an aggregation in a transient phase which exists for several minutes. Finally, threedimensional islands are established with bulk-crystalline structure involving substantial mass transport on the surface and morphological roughening. By applying the Kolmogorov-Johnson-Mehl-Avrami model the activation energies of the temperature-driven sub-processes can be derived from the time evolution of the NEXAFS signal.}, language = {en} } @article{NguyenMuellerParketal.2014, author = {Nguyen, Tu N. and M{\"u}ller, Laura S. M. and Park, Sung Hee and Siegel, T. Nicolai and G{\"u}nzl, Arthur}, title = {Promoter occupancy of the basal class I transcription factor A differs strongly between active and silent VSG expression sites in Trypanosoma brucei}, series = {Nucleic Acid Research}, volume = {42}, journal = {Nucleic Acid Research}, number = {5}, issn = {1362-4962}, doi = {10.1093/nar/gkt1301}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-117232}, pages = {3164-3176}, year = {2014}, abstract = {Monoallelic expression within a gene family is found in pathogens exhibiting antigenic variation and in mammalian olfactory neurons. Trypanosoma brucei, a lethal parasite living in the human bloodstream, expresses variant surface glycoprotein (VSG) from 1 of 15 bloodstream expression sites (BESs) by virtue of a multifunctional RNA polymerase I. The active BES is transcribed in an extranucleolar compartment termed the expression site body (ESB), whereas silent BESs, located elsewhere within the nucleus, are repressed epigenetically. The regulatory mechanisms, however, are poorly understood. Here we show that two essential subunits of the basal class I transcription factor A (CITFA) predominantly occupied the promoter of the active BES relative to that of a silent BES, a phenotype that was maintained after switching BESs in situ. In these experiments, high promoter occupancy of CITFA was coupled to high levels of both promoter-proximal RNA abundance and RNA polymerase I occupancy. Accordingly, fluorescently tagged CITFA-7 was concentrated in the nucleolus and the ESB. Because a ChIP-seq analysis found that along the entire BES, CITFA-7 is specifically enriched only at the promoter, our data strongly indicate that monoallelic BES transcription is activated by a mechanism that functions at the level of transcription initiation.}, language = {en} } @article{TrafimowAmrheinAreshenkoffetal.2018, author = {Trafimow, David and Amrhein, Valentin and Areshenkoff, Corson N. and Barrera-Causil, Carlos J. and Beh, Eric J. and Bilgi{\c{c}}, Yusuf K. and Bono, Roser and Bradley, Michael T. and Briggs, William M. and Cepeda-Freyre, H{\´e}ctor A. and Chaigneau, Sergio E. and Ciocca, Daniel R. and Correa, Juan C. and Cousineau, Denis and de Boer, Michiel R. and Dhar, Subhra S. and Dolgov, Igor and G{\´o}mez-Benito, Juana and Grendar, Marian and Grice, James W. and Guerrero-Gimenez, Martin E. and Guti{\´e}rrez, Andr{\´e}s and Huedo-Medina, Tania B. and Jaffe, Klaus and Janyan, Armina and Karimnezhad, Ali and Korner-Nievergelt, Fr{\"a}nzi and Kosugi, Koji and Lachmair, Martin and Ledesma, Rub{\´e}n D. and Limongi, Roberto and Liuzza, Marco T. and Lombardo, Rosaria and Marks, Michael J. and Meinlschmidt, Gunther and Nalborczyk, Ladislas and Nguyen, Hung T. and Ospina, Raydonal and Perezgonzalez, Jose D. and Pfister, Roland and Rahona, Juan J. and Rodr{\´i}guez-Medina, David A. and Rom{\~a}o, Xavier and Ruiz-Fern{\´a}ndez, Susana and Suarez, Isabel and Tegethoff, Marion and Tejo, Mauricio and van de Schoot, Rens and Vankov, Ivan I. and Velasco-Forero, Santiago and Wang, Tonghui and Yamada, Yuki and Zoppino, Felipe C. M. and Marmolejo-Ramos, Fernando}, title = {Manipulating the Alpha Level Cannot Cure Significance Testing}, series = {Frontiers in Psychology}, volume = {9}, journal = {Frontiers in Psychology}, number = {699}, issn = {1664-1078}, doi = {10.3389/fpsyg.2018.00699}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-189973}, year = {2018}, abstract = {We argue that making accept/reject decisions on scientific hypotheses, including a recent call for changing the canonical alpha level from p = 0.05 to p = 0.005, is deleterious for the finding of new discoveries and the progress of science. Given that blanket and variable alpha levels both are problematic, it is sensible to dispense with significance testing altogether. There are alternatives that address study design and sample size much more directly than significance testing does; but none of the statistical tools should be taken as the new magic method giving clear-cut mechanical answers. Inference should not be based on single studies at all, but on cumulative evidence from multiple independent studies. When evaluating the strength of the evidence, we should consider, for example, auxiliary assumptions, the strength of the experimental design, and implications for applications. To boil all this down to a binary decision based on a p-value threshold of 0.05, 0.01, 0.005, or anything else, is not acceptable.}, language = {en} }