@unpublished{Nassourou2010, author = {Nassourou, Mohamadou}, title = {Reference Architecture, Design of Cascading Style Sheets Processing Model}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-51328}, year = {2010}, abstract = {The technique of using Cascading Style Sheets (CSS) to format and present structured data is called CSS processing model. For instance a CSS processing model for XML documents describes steps involved in formatting and presenting XML documents on screens or papers. Many software applications such as browsers and XML editors have their own CSS processing models which are part of their rendering engines. For instance each browser based on its CSS processing model renders CSS layout differently, as a result an inconsistency in the support of CSS features arises. Some browsers support more CSS features than others, and the rendering itself varies. Moreover the W3C standards are not even adhered by some browsers such as Internet Explorer. Test suites and other hacks and filters cannot definitely solve these problems, because these solutions are temporary and fragile. To palliate this inconsistency and browser compatibility issues with respect to CSS, a reference CSS processing model is needed. By extension it could even allow interoperability across CSS rendering engines. A reference architecture would provide common software architecture and interfaces, and facilitate refactoring, reuse, and automated unit testing. In [2] a reference architecture for browsers has been proposed. However this reference architecture is a macro reference model which does not consider separately individual components of rendering and layout engines. In this paper an attempt to develop a reference architecture for CSS processing models is discussed. In addition the Vex editor [3] rendering and layout engines, as well as an extended version of the editor used in TextGrid project [5] are also presented in order to validate the proposed reference architecture.}, subject = {Cascading Style Sheets}, language = {en} } @unpublished{HennigPrustyKauferetal.2021, author = {Hennig, Thomas and Prusty, Archana B. and Kaufer, Benedikt and Whisnant, Adam W. and Lodha, Manivel and Enders, Antje and Thomas, Julius and Kasimir, Francesca and Grothey, Arnhild and Herb, Stefanie and J{\"u}rges, Christopher and Meister, Gunter and Erhard, Florian and D{\"o}lken, Lars and Prusty, Bhupesh K.}, title = {Selective inhibition of microRNA processing by a herpesvirus-encoded microRNA triggers virus reactivation from latency}, edition = {submitted version}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-267858}, year = {2021}, abstract = {Herpesviruses have mastered host cell modulation and immune evasion to augment productive infection, life-long latency and reactivation thereof 1,2. A long appreciated, yet elusively defined relationship exists between the lytic-latent switch and viral non-coding RNAs 3,4. Here, we identify miRNA-mediated inhibition of miRNA processing as a novel cellular mechanism that human herpesvirus 6A (HHV-6A) exploits to disrupt mitochondrial architecture, evade intrinsic host defense and drive the latent-lytic switch. We demonstrate that virus-encoded miR-aU14 selectively inhibits the processing of multiple miR-30 family members by direct interaction with the respective pri-miRNA hairpin loops. Subsequent loss of miR-30 and activation of miR-30/p53/Drp1 axis triggers a profound disruption of mitochondrial architecture, which impairs induction of type I interferons and is necessary for both productive infection and virus reactivation. Ectopic expression of miR-aU14 was sufficient to trigger virus reactivation from latency thereby identifying it as a readily drugable master regulator of the herpesvirus latent-lytic switch. Our results show that miRNA-mediated inhibition of miRNA processing represents a generalized cellular mechanism that can be exploited to selectively target individual members of miRNA families. We anticipate that targeting miR-aU14 provides exciting therapeutic options for preventing herpesvirus reactivations in HHV-6-associated disorders like myalgic encephalitis/chronic fatigue syndrome (ME/CFS) and Long-COVID.}, language = {en} } @unpublished{HeidenreichGassenmaierAnkenbrandetal.2021, author = {Heidenreich, Julius F. and Gassenmaier, Tobias and Ankenbrand, Markus J. and Bley, Thorsten A. and Wech, Tobias}, title = {Self-configuring nnU-net pipeline enables fully automatic infarct segmentation in late enhancement MRI after myocardial infarction}, edition = {accepted version}, doi = {10.1016/j.ejrad.2021.109817}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-323418}, year = {2021}, abstract = {Purpose To fully automatically derive quantitative parameters from late gadolinium enhancement (LGE) cardiac MR (CMR) in patients with myocardial infarction and to investigate if phase sensitive or magnitude reconstructions or a combination of both results in best segmentation accuracy. Methods In this retrospective single center study, a convolutional neural network with a U-Net architecture with a self-configuring framework ("nnU-net") was trained for segmentation of left ventricular myocardium and infarct zone in LGE-CMR. A database of 170 examinations from 78 patients with history of myocardial infarction was assembled. Separate fitting of the model was performed, using phase sensitive inversion recovery, the magnitude reconstruction or both contrasts as input channels. Manual labelling served as ground truth. In a subset of 10 patients, the performance of the trained models was evaluated and quantitatively compared by determination of the S{\o}rensen-Dice similarity coefficient (DSC) and volumes of the infarct zone compared with the manual ground truth using Pearson's r correlation and Bland-Altman analysis. Results The model achieved high similarity coefficients for myocardium and scar tissue. No significant difference was observed between using PSIR, magnitude reconstruction or both contrasts as input (PSIR and MAG; mean DSC: 0.83 ± 0.03 for myocardium and 0.72 ± 0.08 for scars). A strong correlation for volumes of infarct zone was observed between manual and model-based approach (r = 0.96), with a significant underestimation of the volumes obtained from the neural network. Conclusion The self-configuring nnU-net achieves predictions with strong agreement compared to manual segmentation, proving the potential as a promising tool to provide fully automatic quantitative evaluation of LGE-CMR.}, language = {en} } @unpublished{ArrowsmithBoehnkeBraunschweigetal.2017, author = {Arrowsmith, Merle and B{\"o}hnke, Julian and Braunschweig, Holger and Deißenberger, Andrea and Dewhurst, Rian and Ewing, William and H{\"o}rl, Christian and Mies, Jan and Muessig, Jonas}, title = {Simple Solution-Phase Syntheses of Tetrahalodiboranes(4) and their Labile Dimethylsulfide Adducts}, series = {Chemical Communications}, volume = {53}, journal = {Chemical Communications}, doi = {10.1039/C7CC03148C}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-149438}, pages = {8265-8267}, year = {2017}, abstract = {Convenient, solution-phase syntheses of tetrahalodiboranes(4) B\(_2\)F\(_4\), B\(_2\)Cl\(_4\) and B\(_2\)I\(_4\) are presented herein from common precursor B\(_2\)Br\(_4\). In addition, the dimethylsulfide adducts B\(_2\)Cl\(_4\)(SMe\(_2\))\(_2\) and B\(_2\)Br\(_4\)(SMe\(_2\))\(_2\) are conveniently prepared in one-step syntheses from the commercially-available starting material B\(_2\)(NMe\(_2\))\(_4\). The results provide simple access to the full range of tetrahalodiboranes(4) for the exploration of their untapped synthetic potential.}, language = {en} } @unpublished{BruecknerStennettHessetal.2019, author = {Br{\"u}ckner, Tobias and Stennett, Tom E. and Heß, Merlin and Braunschweig, Holger}, title = {Single and Double Hydroboration of B-B Triple Bonds and Conver- gent Routes to a Cationic Tetraborane}, series = {Journal of the American Chemical Society}, journal = {Journal of the American Chemical Society}, doi = {10.1021/jacs.9b07991}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-188632}, year = {2019}, abstract = {A compound with a boron-boron triple bond is shown to undergo stepwise hydroboration reactions with catecholborane to yield an unsymmetrical hydro(boryl)diborene and a 2,3-dihydrotetraborane. Abstraction of H- from the latter compound produces an unusual cationic, planar tetraborane with a hydrogen atom bridging the central B2 moiety. Spectroscopic and crystallographic data and DFT calculations support a 'protonated diborene' structure for this compound, which can also be accessed via direct protonation of the corresponding diborene.}, language = {en} } @unpublished{FerschMalyRueheetal.2023, author = {Fersch, Daniel and Mal{\´y}, Pavel and R{\"u}he, Jessica and Lisinetskii, Victor and Hensen, Matthias and W{\"u}rthner, Frank and Brixner, Tobias}, title = {Single-Molecule Ultrafast Fluorescence-Detected Pump-Probe Microscopy}, doi = {10.25972/OPUS-31348}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-313485}, year = {2023}, abstract = {We introduce fluorescence-detected pump-probe microscopy by combining a wavelength-tunable ultrafast laser with a confocal scanning fluorescence microscope, enabling access to the femtosecond time scale on the micrometer spatial scale. In addition, we obtain spectral information from Fourier transformation over excitation pulse-pair time delays. We demonstrate this new approach on a model system of a terrylene bisimide (TBI) dye embedded in a PMMA matrix and acquire the linear excitation spectrum as well as time-dependent pump-probe spectra simultaneously. We then push the technique towards single TBI molecules and analyze the statistical distribution of their excitation spectra. Furthermore, we demonstrate the ultrafast transient evolution of several individual molecules, highlighting their different behavior in contrast to the ensemble due to their individual local environment. By correlating the linear and nonlinear spectra, we assess the effect of the molecular environment on the excited-state energy.}, subject = {Fluoreszenz}, language = {en} } @unpublished{ScheitlGhaemMaghamiLenzetal.2020, author = {Scheitl, Carolin P.M. and Ghaem Maghami, Mohammad and Lenz, Ann-Kathrin and H{\"o}bartner, Claudia}, title = {Site-specific RNA methylation by a methyltransferase ribozyme}, series = {Nature}, journal = {Nature}, doi = {10.1038/s41586-020-2854-z}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-218687}, year = {2020}, abstract = {Nearly all classes of coding and non-coding RNA undergo post-transcriptional modification including RNA methylation. Methylated nucleotides belong to the evolutionarily most conserved features of tRNA and rRNA.1,2 Many contemporary methyltransferases use the universal cofactor S-adenosylmethionine (SAM) as methyl group donor. This and other nucleotide-derived cofactors are considered as evolutionary leftovers from an RNA World, in which ribozymes may have catalysed essential metabolic reactions beyond self-replication.3 Chemically diverse ribozymes seem to have been lost in Nature, but may be reconstructed in the laboratory by in vitro selection. Here, we report a methyltransferase ribozyme that catalyses the site-specific installation of 1-methyladenosine (m1A) in a substrate RNA, utilizing O6-methylguanine (m6G) as a small-molecule cofactor. The ribozyme shows a broad RNA sequence scope, as exemplified by site-specific adenosine methylation in tRNAs. This finding provides fundamental insights into RNA's catalytic abilities, serves a synthetic tool to install m1A in RNA, and may pave the way to in vitro evolution of other methyltransferase and demethylase ribozymes.}, language = {en} } @unpublished{Dandekar2007, author = {Dandekar, Thomas}, title = {Some general system properties of a living observer and the environment he explores}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-33537}, year = {2007}, abstract = {In a nice assay published in Nature in 1993 the physicist Richard God III started from a human observer and made a number of witty conclusions about our future prospects giving estimates for the existence of the Berlin Wall, the human race and all the rest of the universe. In the same spirit, we derive implications for "the meaning of life, the universe and all the rest" from few principles. Adams´ absurd answer "42" tells the lesson "garbage in / garbage out" - or suggests that the question is non calculable. We show that experience of "meaning" and to decide fundamental questions which can not be decided by formal systems imply central properties of life: Ever higher levels of internal representation of the world and an escalating tendency to become more complex. An observer, "collecting observations" and three measures for complexity are examined. A theory on living systems is derived focussing on their internal representation of information. Living systems are more complex than Kolmogorov complexity ("life is NOT simple") and overcome decision limits (G{\"o}del theorem) for formal systems as illustrated for cell cycle. Only a world with very fine tuned environments allows life. Such a world is itself rather complex and hence excessive large in its space of different states - a living observer has thus a high probability to reside in a complex and fine tuned universe.}, subject = {Komplex }, language = {en} } @unpublished{HuberPresWittmannetal.2019, author = {Huber, Bernhard and Pres, Sebastian and Wittmann, Emanuel and Dietrich, Lysanne and L{\"u}ttig, Julian and Fersch, Daniel and Krauss, Enno and Friedrich, Daniel and Kern, Johannes and Lisinetskii, Victor and Hensen, Matthias and Hecht, Bert and Bratschitsch, Rudolf and Riedle, Eberhard and Brixner, Tobias}, title = {Space- and time-resolved UV-to-NIR surface spectroscopy and 2D nanoscopy at 1 MHz repetition rate}, issn = {0034-6748}, doi = {10.1063/1.5115322}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-191906}, year = {2019}, abstract = {We describe a setup for time-resolved photoemission electron microscopy (TRPEEM) with aberration correction enabling 3 nm spatial resolution and sub-20 fs temporal resolution. The latter is realized by our development of a widely tunable (215-970 nm) noncollinear optical parametric amplifier (NOPA) at 1 MHz repetition rate. We discuss several exemplary applications. Efficient photoemission from plasmonic Au nanoresonators is investigated with phase-coherent pulse pairs from an actively stabilized interferometer. More complex excitation fields are created with a liquid-crystal-based pulse shaper enabling amplitude and phase shaping of NOPA pulses with spectral components from 600 to 800 nm. With this system we demonstrate spectroscopy within a single plasmonic nanoslit resonator by spectral amplitude shaping and investigate the local field dynamics with coherent two-dimensional (2D) spectroscopy at the nanometer length scale ("2D nanoscopy"). We show that the local response varies across a distance as small as 33 nm in our sample. Further, we report two-color pump-probe experiments using two independent NOPA beamlines. We extract local variations of the excited-state dynamics of a monolayered 2D material (WSe2) that we correlate with low-energy electron microscopy (LEEM) and reflectivity (LEER) measurements. Finally, we demonstrate the in-situ sample preparation capabilities for organic thin films and their characterization via spatially resolved electron diffraction and dark-field LEEM.}, language = {en} } @unpublished{ArrowsmithDoemlingSchmidtetal.2019, author = {Arrowsmith, Merle and D{\"o}mling, Michael and Schmidt, Uwe and Werner, Luis and Castro, Abril C. and Jim{\´e}nez-Halla, J. Oscar C. and M{\"u}ssig, Jonas and Prieschl, Dominic and Braunschweig, Holger}, title = {Spontaneous trans-Selective Transfer Hydrogenation of Apolar B=B Double Bonds}, series = {Angewandte Chemie, International Edition}, journal = {Angewandte Chemie, International Edition}, doi = {10.1002/anie.201902656}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-184874}, year = {2019}, abstract = {The transfer hydrogenation of NHC-supported diborenes with dimethylamine borane proceeds with high selectivity for the trans-1,2-dihydrodiboranes(6). DFT calculations suggest a stepwise proton-first-hydride-second reaction mechanism via an intermediate μ-hydrodiboronium dimethylaminoborate ion pair.}, language = {en} } @unpublished{EnglertStoyArrowsmithetal.2019, author = {Englert, Lukas and Stoy, Andreas and Arrowsmith, Merle and M{\"u}ssig, Jonas H. and Thaler, Melanie and Deißenberger, Andrea and H{\"a}fner, Alena and B{\"o}hnke, Julian and Hupp, Florian and Seufert, Jens and Mies, Jan and Damme, Alexander and Dellermann, Theresa and Hammond, Kai and Kupfer, Thomas and Radacki, Krzysztof and Thiess, Torsten and Braunschweig, Holger}, title = {Stable Lewis Base Adducts of Tetrahalodiboranes: Synthetic Methods and Structural Diversity}, series = {Chemistry - A European Journal}, journal = {Chemistry - A European Journal}, doi = {10.1002/chem.201901437}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-184888}, year = {2019}, abstract = {A series of 22 new bis(phosphine), bis(carbene) and bis(isonitrile) tetrahalodiborane adducts has been synthesized, either by direct adduct formation with highly sensitive B2X4 precursors (X = Cl, Br, I) or by ligand exchange at stable B2X4(SMe2)2 precursors (X = Cl, Br) with labile dimethylsulfide ligands. The isolated compounds have been fully characterized using NMR spectroscopic, (C,H,N)- elemental and, for 20 of these compounds, X-ray crystallographic analysis, revealing an unexpected variation in the bonding motifs. Besides the classical B2X4L2 diborane(6) adducts, some of the more sterically demanding carbene ligands induce a halide displacement leading to the first halide-bridged monocationic diboron species, [B2X3L2]A (A = BCl4, Br, I). Furthermore, low-temperature 1:1 reactions of B2Cl4 with sterically demanding N-heterocyclic carbenes led to the formation of kinetically unstable mono-adducts, one of which was structurally characterized. A comparison of the NMR and structural data of new and literature-known bis-adducts shows several trends pertaining to the nature of the halides and the stereoelectronic properties of the Lewis bases employed.}, language = {en} } @unpublished{Volkmann2012, author = {Volkmann, Armin}, title = {Stempelverzierte Keramikfunde der V{\"o}lkerwanderungszeit im Barbaricum - Neue Funde vom fr{\"u}hmittelalterlichen Burgwall bei Kopchin (Lkr. Bautzen)}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-74432}, year = {2012}, abstract = {Durch die systematische Sichtung des Fundmaterials des fr{\"u}hmittelalterlichen Burgwalls von Kopchin in der Oberlausitz konnten einige Keramikscherben identifiziert werden, die wohl {\"a}lter als bisher angenommen sind und in die V{\"o}lkerwanderungszeit datieren. Dies ist von besonderer Relevanz, da f{\"u}r Nordostdeutschland traditionell eine Besiedlungsl{\"u}cke im 5.-7. Jh. AD postuliert wird. Dieser Hiatus ist offenbar teils auch der schwierigen sicheren Datierung der oft recht unspezifischen Keramiktypen geschuldet. So konnten mit wachsendem Kenntnisstand dieser Keramiken in den letzten Jahren auch einige v{\"o}lkerwanderungszeitliche Fundstellen, besonders in Nordbrandenburg und im deutsch-polnischen Pommern lokalisiert werden. In Nordost-Sachsen sind die vorgestellten singul{\"a}ren Funde des 5.-6. Jhs. AD jedoch bisher ohne sichere Parallelen, auch wenn mittlerweile einige Fundstellen der V{\"o}lkerwanderungszeit in der Region erkannt worden sind.}, subject = {Germanen}, language = {de} } @unpublished{ScheitlMieczkowskiSchindelinetal.2022, author = {Scheitl, Carolin P. M. and Mieczkowski, Mateusz and Schindelin, Hermann and H{\"o}bartner, Claudia}, title = {Structure and mechanism of the methyltransferase ribozyme MTR1}, series = {Nature Chemical Biology}, journal = {Nature Chemical Biology}, edition = {submitted version}, doi = {10.1038/s41589-022-00976-x}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-272170}, year = {2022}, abstract = {RNA-catalysed RNA methylation was recently shown to be part of the catalytic repertoire of ribozymes. The methyltransferase ribozyme MTR1 catalyses the site-specific synthesis of 1-methyladenosine (m\(^1\)A) in RNA, using O\(^6\)-methylguanine (m\(^6\)G) as methyl group donor. Here we report the crystal structure of MTR1 at a resolution of 2.8 {\AA}, which reveals a guanine binding site reminiscent of natural guanine riboswitches. The structure represents the postcatalytic state of a split ribozyme in complex with the m1A-containing RNA product and the demethylated cofactor guanine. The structural data suggest the mechanistic involvement of a protonated cytidine in the methyl transfer reaction. A synergistic effect of two 2'-O-methylated ribose residues in the active site results in accelerated methyl group transfer. Supported by these results, it seems plausible that modified nucleotides may have enhanced early RNA catalysis and that metabolite-binding riboswitches may resemble inactivated ribozymes that have lost their catalytic activity during evolution.}, language = {en} } @unpublished{BruecknerArrowsmithHessetal.2019, author = {Br{\"u}ckner, Tobias and Arrowsmith, Merle and Heß, Merlin and Hammond, Kai and M{\"u}ller, Marcel and Braunschweig, Holger}, title = {Synthesis of fused B,N-heterocycles by alkyne cleavage, NHC ring-expansion and C-H activation at a diboryne}, series = {Chemical Communications}, journal = {Chemical Communications}, doi = {10.1039/C9CC02657F}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-184899}, year = {2019}, abstract = {The addition of alkynes to a staturated N-heterocyclic carbene (NHC)-supported diboryne results in spontaneous cycloaddition, with complete B≡B and C≡C triple bond cleavage, NHC ring- expansion and activation of a variety of C-H bonds, leading to the formation of complex mixtures of fused B,N-heterocycles.}, language = {en} } @unpublished{CidHermannRadcliffeetal.2018, author = {Cid, Jessica and Hermann, Alexander and Radcliffe, James E. and Curless, Liam D. and Braunschweig, Holger and Ingleson, Michael J.}, title = {Synthesis of Unsymmetrical Diboron(5) Compounds and Their Conversion to Diboron(5) Cations}, series = {Organometallics}, journal = {Organometallics}, doi = {10.1021/acs.organomet.8b00288}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-164299}, year = {2018}, abstract = {Reaction of bis-catecholatodiboron-NHC adducts, B\(_2\)Cat\(_2\)(NHC), (NHC = IMe (tetramethylimidazol-2-ylidene), IMes (1,3-dimesitylimidazol-2-ylidene) or IDIPP (1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene)) with BCl3 results in the replacement of the catecholato group bound to the four coordinate boron with two chlorides to yield diboron(5) Lewis acid-base adducts of formula CatB-BCl\(_2\)(NHC). These compounds are precursors to diboron(5) monocations, accessed by adding AlCl\(_3\) or K[B(C\(_6\)F\(_5\))\(_4\)] as halide abstraction agents in the presence of a Lewis base. The substitution of the chlorides of CatB-BCl\(_2\)(NHC) for hydrides is achieved using Bu\(_3\)SnH and a halide abstracting agent to form 1,1-dihydrodiboron(5) compounds, CatB-BH\(_2\)(NHC). Attempts to generate diboron(4) monocations of formula [CatB-B(Y)(NHC)]\(^+\) (Y = Cl or H) led to the rapid formation of CatBY.}, language = {en} } @unpublished{HaendelSchoelvinck2019, author = {H{\"a}ndel, Barbara and Sch{\"o}lvinck, Marieke}, title = {The brain during free movement - what can we learn from the animal model}, series = {Brain Research}, journal = {Brain Research}, edition = {accepted manuscript}, doi = {10.1016/j.brainres.2017.09.003}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-251406}, year = {2019}, abstract = {Animals, just like humans, can freely move. They do so for various important reasons, such as finding food and escaping predators. Observing these behaviors can inform us about the underlying cognitive processes. In addition, while humans can convey complicated information easily through speaking, animals need to move their bodies to communicate. This has prompted many creative solutions by animal neuroscientists to enable studying the brain during movement. In this review, we first summarize how animal researchers record from the brain while an animal is moving, by describing the most common neural recording techniques in animals and how they were adapted to record during movement. We further discuss the challenge of controlling or monitoring sensory input during free movement. However, not only is free movement a necessity to reflect the outcome of certain internal cognitive processes in animals, it is also a fascinating field of research since certain crucial behavioral patterns can only be observed and studied during free movement. Therefore, in a second part of the review, we focus on some key findings in animal research that specifically address the interaction between free movement and brain activity. First, focusing on walking as a fundamental form of free movement, we discuss how important such intentional movements are for understanding processes as diverse as spatial navigation, active sensing, and complex motor planning. Second, we propose the idea of regarding free movement as the expression of a behavioral state. This view can help to understand the general influence of movement on brain function. Together, the technological advancements towards recording from the brain during movement, and the scientific questions asked about the brain engaged in movement, make animal research highly valuable to research into the human "moving brain".}, language = {en} } @unpublished{HocheSchmittHumeniuketal.2017, author = {Hoche, Joscha and Schmitt, Hans-Christian and Humeniuk, Alexander and Fischer, Ingo and Mitrić, Roland and R{\"o}hr, Merle I. S.}, title = {The mechanism of excimer formation: an experimental and theoretical study on the pyrene dimer}, series = {Physical Chemistry Chemical Physics}, journal = {Physical Chemistry Chemical Physics}, doi = {10.1039/C7CP03990E}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-159656}, year = {2017}, abstract = {The understanding of excimer formation in organic materials is of fundamental importance, since excimers profoundly influence their functional performance in applications such as light-harvesting, photovoltaics or organic electronics. We present a joint experimental and theoretical study of the ultrafast dynamics of excimer formation in the pyrene dimer in a supersonic jet, which is the archetype of an excimer forming system. We perform simulations of the nonadiabatic photodynamics in the frame of TDDFT that reveal two distinct excimer formation pathways in the gas-phase dimer. The first pathway involves local excited state relaxation close to the initial Franck-Condon geometry that is characterized by a strong excitation of the stacking coordinate exhibiting damped oscillations with a period of 350 fs that persist for several picoseconds. The second excimer forming pathway involves large amplitude oscillations along the parallel shift coordinate with a period of ≈900 fs that after intramolecular vibrational energy redistribution leads to the formation of a perfectly stacked dimer. The electronic relaxation within the excitonic manifold is mediated by the presence of intermolecular conical intersections formed between fully delocalized excitonic states. Such conical intersections may generally arise in stacked π-conjugated aggregates due to the interplay between the long-range and short-range electronic coupling. The simulations are supported by picosecond photoionization experiments in a supersonic jet that provide a time-constant for the excimer formation of around 6-7 ps, in good agreement with theory. Finally, in order to explore how the crystal environment influences the excimer formation dynamics we perform large scale QM/MM nonadiabatic dynamics simulations on a pyrene crystal in the framework of the long-range corrected tight-binding TDDFT. In contrast to the isolated dimer, the excimer formation in the crystal follows a single reaction pathway in which the initially excited parallel slip motion is strongly damped by the interaction with the surrounding molecules leading to the slow excimer stabilization on a picosecond time scale.}, language = {en} } @unpublished{Reiss2012, author = {Reiss, Harald}, title = {Time scales and existence of time holes in non-transparent media}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-73554}, year = {2012}, abstract = {The analysis presented in this paper applies to experimental situations where observers or objects to be studied, all at stationary positions, are located in environments the optical thickness of which is strongly different. Non-transparent media comprise thin metallic films, packed or fluidised beds, superconductors, the Earth's crust, and even dark clouds and other cosmological objects. The analysis applies mapping functions that correlate physical events, e, in non-transparent media, with their images, f(e), tentatively located on standard physical time scale. The analysis demonstrates, however, that physical time, in its rigorous sense, does not exist under non-transparency conditions. A proof of this conclusion is attempted in three steps: i) the theorem "there is no time without space and events" is accepted, (ii) images f[e(s,t)] do not constitute a dense, uncountably infinite set, and (iii) sets of images that are not uncountably infinite do not create physical time but only time-like sequences. As a consequence, mapping f[e(s,t)] in non-transparent space does not create physical analogues to the mathematical structure of the ordered, dense half-set R+ of real numbers, and reverse mapping, f-1f[e(s,t)], the mathematical inverse problem, would not allow unique identification and reconstruction of original events from their images. In these cases, causality as well as invariance of physical processes under time reversal, might be violated. An interesting problem is whether temporal cloaking (a time hole) in a transparent medium, as very recently reported in the literature, can be explained by the present analysis. Existence of time holes could perhaps be possible, not in transparent but in non-transparent media, as follows from the sequence of images, f[e(s,t)], that is not uncountably infinite, in contrast to R+. Impacts are expected for understanding physical diffusion-like, radiative transfer processes and stability models to protect superconductors against quenchs. There might be impacts also in relativity, quantum mechanics, nuclear decay, or in systems close to their phase transitions. The analysis is not restricted to objects of laboratory dimensions.}, subject = {Zeitrichtung}, language = {en} } @unpublished{Nassourou2012, author = {Nassourou, Mohamadou}, title = {Towards a Knowledge-Based Learning System for The Quranic Text}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-70003}, year = {2012}, abstract = {In this research, an attempt to create a knowledge-based learning system for the Quranic text has been performed. The knowledge base is made up of the Quranic text along with detailed information about each chapter and verse, and some rules. The system offers the possibility to study the Quran through web-based interfaces, implementing novel visualization techniques for browsing, querying, consulting, and testing the acquired knowledge. Additionally the system possesses knowledge acquisition facilities for maintaining the knowledge base.}, subject = {Wissensbanksystem}, language = {en} } @unpublished{HermannArrowsmithTrujilloGonzalezetal.2020, author = {Hermann, Alexander and Arrowsmith, Merle and Trujillo-Gonzalez, Daniel and Jim{\´e}nez-Halla, J. Oscar C. and Vargas, Alfredo and Braunschweig, Holger}, title = {Trapping of a Borirane Intermediate in the Reductive Coupling of an Arylborane to a Diborene}, series = {Journal of the American Chemical Society}, journal = {Journal of the American Chemical Society}, doi = {10.1021/jacs.0c02306}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-203140}, year = {2020}, abstract = {The reductive coupling of an NHC-stabilized aryldibromoborane yields a mixture of trans- and cis-diborenes in which the aryl groups are coplanar with the diborene core. Under dilute reduction conditions two diastereomers of a borirane-borane intermediate are isolated, which upon further reduction give rise to the aforementioned diborene mixture. DFT calculations suggest a mechanism proceeding via nucleophilic attack of a dicoordinate borylene intermediate on the aryl ring and subsequent intramolecular B-B bond formation.}, language = {en} } @unpublished{SchmidtFantuzziArrowsmithetal.2020, author = {Schmidt, Uwe and Fantuzzi, Felipe and Arrowsmith, Merle and Hermann, Alexander and Prieschl, Dominic and Rempel, Anna and Engels, Bernd and Braunschweig, Holger}, title = {Tuneable reduction of cymantrenylboranes to diborenes or borylene-derived boratafulvenes}, series = {Chemical Communications}, journal = {Chemical Communications}, doi = {10.1039/D0CC06398C}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-222149}, year = {2020}, abstract = {Whereas the reduction of N-heterocyclic carbene (NHC)-stabilised cymantrenyldibromoboranes, (NHC)BBr\(_2\)Cym, in benzene results in formation of the corresponding diborenes (NHC)\(_2\)B\(_2\)Cym\(_2\), a change of solvent to THF yields a borylene of the form (NHC)\(_2\)BCym, stabilised through its boratafulvene resonance form.}, language = {en} } @unpublished{PetersenLindnerMitric2018, author = {Petersen, Jens and Lindner, Joachim O. and Mitric, Roland}, title = {Ultrafast Photodynamics of Glucose}, series = {Journal of Physical Chemistry B}, journal = {Journal of Physical Chemistry B}, doi = {10.1021/acs.jpcb.7b08602}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-159155}, year = {2018}, abstract = {We have investigated the photodynamics of \(\beta\)-D-glucose employing our field-induced surface hopping method (FISH), which allows us to simulate the coupled electron-nuclear dynamics, including explicitly nonadiabatic effects and light-induced excitation. Our results reveal that from the initially populated S\(_{1}\) and S\(_{2}\) states, glucose returns nonradiatively to the ground state within about 200 fs. This takes place mainly via conical intersections (CIs) whose geometries in most cases involve the elongation of a single O-H bond, while in some instances ring-opening due to dissociation of a C-O bond is observed. Experimentally, excitation to a distinct excited electronic state is improbable due to the presence of a dense manifold of states bearing similar oscillator strengths. Our FISH simulations explicitly including a UV laser pulse of 6.43 eV photon energy reveals that after initial excitation the population is almost equally spread over several close-lying electronic states. This is followed by a fast nonradiative decay on the time scale of 100-200 fs, with the final return to the ground state proceeding via the S\(_{1}\) state through the same types of CIs as observed in the field-free simulations.}, language = {en} } @unpublished{Nassourou2010, author = {Nassourou, Mohamadou}, title = {Understanding the Vex Rendering Engine}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-51333}, year = {2010}, abstract = {The Visual Editor for XML (Vex)[1] used by TextGrid [2]and other applications has got rendering and layout engines. The layout engine is well documented but the rendering engine is not. This lack of documenting the rendering engine has made refactoring and extending the editor hard and tedious. For instance many CSS2.1 and upcoming CSS3 properties have not been implemented. Software developers in different projects such as TextGrid using Vex would like to update its CSS rendering engine in order to provide advanced user interfaces as well as support different document types. In order to minimize the effort of extending Vex functionality, I found it beneficial to write a basic documentation about Vex software architecture in general and its CSS rendering engine in particular. The documentation is mainly based on the idea of architectural layered diagrams. In fact layered diagrams can help developers understand software's source code faster and easier in order to alter it, and fix errors. This paper is written for the purpose of providing direct support for exploration in the comprehension process of Vex source code. It discusses Vex software architecture. The organization of packages that make up the software, the architecture of its CSS rendering engine, an algorithm explaining the working principle of its rendering engine are described.}, subject = {Cascading Style Sheets}, language = {en} } @unpublished{StennettMattockVollertetal.2018, author = {Stennett, Tom and Mattock, James and Vollert, Ivonne and Vargas, Alfredo and Braunschweig, Holger}, title = {Unsymmetrical, Cyclic Diborenes and Thermal Rearrangement to a Borylborylene}, series = {Angewandte Chemie, International Edition}, volume = {57}, journal = {Angewandte Chemie, International Edition}, doi = {10.1002/anie.201800671}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-160258}, pages = {4098-4102}, year = {2018}, abstract = {Cyclic diboranes(4) based on a chelating monoanionic, benzylphosphine linker were prepared by boron-silicon exchange between arylsilanes and B\(_2\)Br\(_4\). Coordination of Lewis bases to the remaining sp\(^2\) boron atom yielded unsymmetrical sp\(^3\)-sp\(^3\) diboranes, which were reduced with KC\(_8\) to their corresponding trans-diborenes. These compounds were studied by a combination of spectroscopic methods, X-ray diffraction and DFT calculations. PMe\(_3\)-stabilized diborene 6 was found to undergo thermal rearrangement to gem- diborene 8. DFT calculations on 8 reveal a polar boron-boron bond, and indicate that the compound is best described as a borylborylene.}, language = {en} } @unpublished{Nassourou2011, author = {Nassourou, Mohamadou}, title = {Using Machine Learning Algorithms for Categorizing Quranic Chaptersby Major Phases of Prophet Mohammad's Messengership}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-66862}, year = {2011}, abstract = {This paper discusses the categorization of Quranic chapters by major phases of Prophet Mohammad's messengership using machine learning algorithms. First, the chapters were categorized by places of revelation using Support Vector Machine and na{\"i}ve Bayesian classifiers separately, and their results were compared to each other, as well as to the existing traditional Islamic and western orientalists classifications. The chapters were categorized into Meccan (revealed in Mecca) and Medinan (revealed in Medina). After that, chapters of each category were clustered using a kind of fuzzy-single linkage clustering approach, in order to correspond to the major phases of Prophet Mohammad's life. The major phases of the Prophet's life were manually derived from the Quranic text, as well as from the secondary Islamic literature e.g hadiths, exegesis. Previous studies on computing the places of revelation of Quranic chapters relied heavily on features extracted from existing background knowledge of the chapters. For instance, it is known that Meccan chapters contain mostly verses about faith and related problems, while Medinan ones encompass verses dealing with social issues, battles…etc. These features are by themselves insufficient as a basis for assigning the chapters to their respective places of revelation. In fact, there are exceptions, since some chapters do contain both Meccan and Medinan features. In this study, features of each category were automatically created from very few chapters, whose places of revelation have been determined through identification of historical facts and events such as battles, migration to Medina…etc. Chapters having unanimously agreed places of revelation were used as the initial training set, while the remaining chapters formed the testing set. The classification process was made recursive by regularly augmenting the training set with correctly classified chapters, in order to classify the whole testing set. Each chapter was preprocessed by removing unimportant words, stemming, and representation with vector space model. The result of this study shows that, the two classifiers have produced useable results, with an outperformance of the support vector machine classifier. This study indicates that, the proposed methodology yields encouraging results for arranging Quranic chapters by phases of Prophet Mohammad's messengership.}, subject = {Koran}, language = {en} } @unpublished{Dandekar2008, author = {Dandekar, Thomas}, title = {Why are nature´s constants so fine-tuned? The case for an escalating complex universe}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-34488}, year = {2008}, abstract = {Why is our universe so fine-tuned? In this preprint we discuss that this is not a strange accident but that fine-tuned universes can be considered to be exceedingly large if one counts the number of observable different states (i.e. one aspect of the more general preprint http://www.opus-bayern.de/uni-wuerzburg/volltexte/2009/3353/). Looking at parameter variation for the same set of physical laws simple and complex processes (including life) and worlds in a multiverse are compared in simple examples. Next the anthropocentric principle is extended as many conditions which are generally interpreted anthropocentric only ensure a large space of different system states. In particular, the observed over-tuning beyond the level for our existence is explainable by these system considerations. More formally, the state space for different systems becomes measurable and comparable looking at their output behaviour. We show that highly interacting processes are more complex then Chaitin complexity, the latter denotes processes not compressible by shorter descriptions (Kolomogorov complexity). The complexity considerations help to better study and compare different processes (programs, living cells, environments and worlds) including dynamic behaviour and can be used for model selection in theoretical physics. Moreover, the large size (in terms of different states) of a world allowing complex processes including life can in a model calculation be determined applying discrete histories from quantum spin-loop theory. Nevertheless there remains a lot to be done - hopefully the preprint stimulates further efforts in this area.}, subject = {Natur}, language = {en} } @unpublished{Kiesler1994, author = {Kiesler, Reinhard}, title = {Zum Stand der Forschung auf dem Gebiete der franz{\"o}sischen Umgangssprache (1994)}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-103365}, pages = {77 S.}, year = {1994}, abstract = {Der Artikel gibt einen {\"U}berblick {\"u}ber die Forschungen zur franz{\"o}sischen Umgangssprache von den Anf{\"a}ngen bis etwa 1992 in vier Abschnitten: 1. Die Anf{\"a}nge, 2. die Sprachschichtenforschung, 3. die Beitr{\"a}ge von Soziolinguistik und Variet{\"a}tenlinguistik und 4. die Arbeiten der "Gegenwart" um 1990. Eine Zusammenfassung und eine ausf{\"u}hrliche Bibliographie schließen den Forschungsbericht ab. Ber{\"u}cksichtigt werden alle sprachlichen Ebenen von der Aussprache {\"u}ber den Wortschatz bis zur Grammatik. Wo es angebracht erscheint, sind Hinweise auf Arbeiten zu anderen Umgangssprachen angef{\"u}hrt.}, subject = {Franz{\"o}sisch}, language = {de} } @unpublished{Schmidt2011, author = {Schmidt, Karin Stella}, title = {Zur Musik Mesopotamiens. Erste Erg{\"a}nzung (2011)}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-65169}, year = {2011}, abstract = {Literaturzusammenstellung zur Musik Mesopotamiens: zu Musiktheorie, Notenschriften, Instrumentenkunde, Auff{\"u}hrungspraxis in Sumer, Akkad, Babylonien, Assyrien}, subject = {Mesopotamien}, language = {de} } @unpublished{Schmitz2012, author = {Schmitz, Barbara}, title = {ΙΟΥΔΙΘ und IUDITH: {\"U}berlegungen zum Verh{\"a}tlnis der Judit-Erz{\"a}hlung in der LXX und der Vulgata}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-108938}, year = {2012}, abstract = {"Das Buch Judit ist in zwei wesentlich voneinander unterschiedenen Textformen {\"u}berliefert: einerseits in der griechischen Fassung und den sich daran anschließenden alten {\"U}bersetzungen (vetus latina, syr., aeth., sah., arm.), zum anderen in der Fassung der lateinischen Vulgata und, mit dieser durchweg parallel laufend, in mittelalterlichen hebr{\"a}ischen Hss." - so fasst Helmut Engel die Textsituation des Buches Judit pr{\"a}gnant zusammen. Damit liegen heute zwei unterschiedliche Textformen der Juditerz{\"a}hlung vor: Die griechische Juditerz{\"a}hlung in der Septuaginta und die lateinische Iuditherz{\"a}hlung in der Vulgata. Beide Textfassungen unterscheiden sich deutlich voneinander: Die Vulgata-Fassung ist gegen{\"u}ber der LXX-Fassung um 20 Prozent k{\"u}rzer; weil die Vulgata-Fassung aber auch umfangreiche Erweiterungen aufweist, teilen LXX und Vulgata nur ungef{\"a}hr die H{\"a}lfte des Textbestandes. Lange ist man davon ausgegangen, dass hinter der Septuaginta- und der Vulgata-Fassung der Juditerz{\"a}hlung ein hebr{\"a}ischer "Ur"-Text gestanden habe. Diese Annahme, die die Forschung seit dem 19. Jh. pr{\"a}gt, gr{\"u}ndet sich im Wesentlichen auf zwei Argumenten: Erstens sei der griechische Text der Septuaginta so durchgehend von einem hebr{\"a}ischen Sprachduktus gepr{\"a}gt, dass man hier von einem hebr{\"a}ischen Originaltext, der recht w{\"o}rtlich ins Griechische {\"u}bertragen worden sei, ausgehen m{\"u}sse. Zweitens spreche Hieronymus (ca. 347-420) in seiner praefatio zu seiner lateinischen {\"U}bertragung von einem ihm vorliegenden "chald{\"a}ischen" Text, der ihm als Vorlage gedient habe. Beide Argumente werden im Folgenden diskutiert: Im ersten Teil wird auf die in den letzten Jahren neu aufgerollte Frage nach der Originalsprache der LXX-Fassung der Juditerz{\"a}hlung eingegangen; der zweite Teil ist der Analyse der praefatio des Hieronymus gewidmet.}, subject = {Judit }, language = {de} }