Further Baire results on the distribution of subsequences

This paper presents results about the distribution of subsequences which are typical in the sense of Baire. The first part is concerned with sequences of the type x_k = n_k*alpha, n_1 < n_2 < n_3 < ..., mod 1. Improving a result of Salat we show that, if the quotients q_k = n_{k+1}/n_k satisfy q_k > 1+ epsilon, then the set of alpha such that (x_k) is uniformly distributed is of first Baire category, i.e. for generic alpha we do not have uniform distribution. Under the stronger assumption lim q_k = infinity one even has maldistribution for generic alpha, the strongest possible contrast to uniform distribution. The second part reverses the point of view by considering appropriately defined Baire spaces S of subsequences. For a fixed well distributed sequence (x_n) we show that there is a set M of measures such that for generic (n_k) in S the set of limit measures of the subsequence (x_{n_k}) is exactly M.Comment: 21 pages, LaTeX2e. Final version. (Somewhat expanded proofs and clarifications, more examples

Effects of processing on the stability of molybdenum oxide ultra-thin films

The effects of wet chemical processing conventionally employed in device fabrication standards are systematically studied on molybdenum oxide (MoOx) ultra-thin films. We have combined x-ray photoelectron spectroscopy (XPS), angle resolved XPS and x-ray reflectivity techniques to provide deep insights into the changes in composition, structure and electronic states upon treatment of films with different initial stoichiometry prepared by reactive sputtering. Our results show significant reduction effects associated with the development of gap states in MoOx, as well as changes in the composition, density and structure of the films, systematically correlated with the initial oxidation state of Mo.Comment: 16 pages, 5 figures, Appendix include

Atmosphärische Nichtmethan-Kohlenwasserstoffe im Großraum Berlin-Brandenburg : Meßtechnik, Bestandsaufnahme und Beiträge zur lokalen Photooxidantienbildung

Nichtmethan-Kohlenwasserstoffe sind in Gegenwart von Stickstoffoxiden (NO, NO2) wichtige Vorläufersubstanzen von troposphärischen Photooxidantien (z. B. Ozon), die beim photochemischen Metabolismus gasförmiger organischer Verbindungen durch Hydroxylradikale (OH) unter Einwirkung von Sonnenlicht gebildet werden. Experimenteller Beitrag dieser Arbeit ist die Charakterisierung, Modifizierung, Optimierung und Qualitätssicherung des zur Messung von leichtflüchtigen atmosphärischen C2-C10 Kohlenwasserstoffen verwendeten mobilen Gaschromatographen (GC) mit Flammenionisationsdetektor (AirmoVOC HC2010). Im Rahmen des vom BIvIBF geförderten Berlin Ozonexperiments BERLIOZ, das im Sommer 1998 im Großraum Berlin/Brandenburg stattfand, wurden an einer ländlichen Bodenstation in Blossin, 40 km südöstlich Berlins, in situ Messungen von 69 Nichtmethan-Kohlenwasserstoffen durchgeführt. im Vorfeld der Feldkampagne wurde der GC einer umfangreichen Qualitätssicherung unterzogen. Bei einer Immissionsvergleichsmessung, die unter Beteiligung aller Arbeitsgruppen stattfand, ergab sich eine mittlere konzentrationsabhängige Abweichung des HC-2010 von ± 16% und ein konstanter Offset (Bias) von 0,71 nmol/m3 (16 pptv) vom Referenzmeßverfahren des Forschungszentrums Jülich. Die Geräteblindwerte waren für die meisten Analyten kleiner 0,3 nmol/m3 (6 pptv). Aus der dreifachen Standardabweichung der Blindwerte ergaben sich die für Außenluftuntersuchungen geforderten Nachweisgrenzen um 0,4 nmol/m3 (10 pptv). Im zweiten Teil dieser Arbeit wurde der BERLIOZ-Datensatz hinsichtlich einer Bestandsaufnahme ausgewertet. Die beobachteten Konzentrationen der einzelnen Kohlenwasserstoffe wiesen jeweils eine logarithmische Normalverteilung auf, die Charakterisierung des Datensatzes erfolgte deshalb nicht anhand von arithmetischem Mittelwert und Standardabweichung, sondern mit geometrischem Mittelwert und multiplikativer Standardabweichung. Anhand der OH-Verlustrate wurde der Einfluß der verschiedenen Kohlenwasserstoffe auf die lokale Bildung von Photooxidantien untersucht. Der natürliche Kohlenwasserstoff Isopren lieferte mit 70% den weitaus größten mittleren Beitrag zur Photooxidantienproduktion am Boden. In der Grenzschicht verlor isopren allerdings seine dominante Rolle. Sein Beitrag schrumpfte mit zunehmender Höhe auf 20-40%. in der in 200 m Höhe beobachteten Abluftfahne Berlins verursachten anthropogene Kohlenwasserstoffe rund 2/3 der OH-Verlustrate, wobei die reaktiven C3/C4-Alkene alleine bereits 50% beitrugen

LaRA 2: parallel and vectorized program for sequence–structure alignment of RNA sequences

Background The function of non-coding RNA sequences is largely determined by their spatial conformation, namely the secondary structure of the molecule, formed by Watson–Crick interactions between nucleotides. Hence, modern RNA alignment algorithms routinely take structural information into account. In order to discover yet unknown RNA families and infer their possible functions, the structural alignment of RNAs is an essential task. This task demands a lot of computational resources, especially for aligning many long sequences, and it therefore requires efficient algorithms that utilize modern hardware when available. A subset of the secondary structures contains overlapping interactions (called pseudoknots), which add additional complexity to the problem and are often ignored in available software. Results We present the SeqAn-based software LaRA 2 that is significantly faster than comparable software for accurate pairwise and multiple alignments of structured RNA sequences. In contrast to other programs our approach can handle arbitrary pseudoknots. As an improved re-implementation of the LaRA tool for structural alignments, LaRA 2 uses multi-threading and vectorization for parallel execution and a new heuristic for computing a lower boundary of the solution. Our algorithmic improvements yield a program that is up to 130 times faster than the previous version. Conclusions With LaRA 2 we provide a tool to analyse large sets of RNA secondary structures in relatively short time, based on structural alignment. The produced alignments can be used to derive structural motifs for the search in genomic databases

LaRA 2: parallel and vectorized program for sequence–structure alignment of RNA sequences

Background The function of non-coding RNA sequences is largely determined by their spatial conformation, namely the secondary structure of the molecule, formed by Watson–Crick interactions between nucleotides. Hence, modern RNA alignment algorithms routinely take structural information into account. In order to discover yet unknown RNA families and infer their possible functions, the structural alignment of RNAs is an essential task. This task demands a lot of computational resources, especially for aligning many long sequences, and it therefore requires efficient algorithms that utilize modern hardware when available. A subset of the secondary structures contains overlapping interactions (called pseudoknots), which add additional complexity to the problem and are often ignored in available software. Results We present the SeqAn-based software LaRA 2 that is significantly faster than comparable software for accurate pairwise and multiple alignments of structured RNA sequences. In contrast to other programs our approach can handle arbitrary pseudoknots. As an improved re-implementation of the LaRA tool for structural alignments, LaRA 2 uses multi-threading and vectorization for parallel execution and a new heuristic for computing a lower boundary of the solution. Our algorithmic improvements yield a program that is up to 130 times faster than the previous version. Conclusions With LaRA 2 we provide a tool to analyse large sets of RNA secondary structures in relatively short time, based on structural alignment. The produced alignments can be used to derive structural motifs for the search in genomic databases

Age, origin and palaeoclimatic implications of peri- and paraglacial boulder-dominated landforms in Rondane, South Norway

Boulder-dominated landforms of periglacial, paraglacial and related origin constitute a valuable, but often unexplored source of palaeoclimatic and morphodynamic information. The timing of landform development initiation and its subsequent stabilization can be linked to past climatic conditions offering the potential to reconstruct cold climatic periods. In this study, Schmidt-hammer exposure-age dating (SHD) was applied to a variety of boulder-dominated landforms (sorted stripes, blockfield, rock-slope failure, paraglacial alluvial fan) in Rondane, eastern South Norway for the first time. On the basis of old and young control points a regional SHD calibration curve was established and successively utilized for the calculation of surface exposure ages for individual landforms. The chronological investigation of development and stabilization of the respective landforms permitted an assessment of Holocene climate variability in Rondane and its impact on overall landform evolution. Our obtained SHD age estimates ranged from 11.44 ± 1.22 ka (ST-D2) to 4.09 ± 1.51 ka (AF1) showing their inactive and relict character. Most surface exposure ages for sorted stripes clustered between 9.88 ± 1.35 ka and 9.25 ± 1.21 ka, hence indicating stabilization during the late stage of the Erdalen Event or shortly thereafter. It is inferred that the blockfield formed prior to the Last Glacial Maximum, was protected by cold-based ice throughout glaciation and shortly reactivated during the Erdalen Event only to subsequently becoming inactive. The surface exposure age of a rock-slope failure (7.58 ± 0.73 ka) falls into the early phase of the Holocene Thermal Maximum (HTM, ~8.0–5.0 ka). This indicates permafrost degradation and/or increasing hydrological pressure negatively influencing slope stability. The paraglacial alluvial fan with its four subsites yielded ages between 8.73 ± 1.63 ka and 4.09 ± 1.51 ka. The old exposure ages point to fan aggradation following regional deglaciation due to paraglacial processes, whereas the younger ages can be explained by increasing precipitation during the onset neoglaciation at ~4.0 ka. Our results underline the importance of meltwater for the activation of periglacial landforms in a continental climate and indicate that the Erdalen Event and immediately following onset of the HTM had major impact on landscape evolution in Rondane. Our obtained surface exposure ages from boulder-dominated landforms in Rondane give important insights into the local palaeoclimatic variability during the Holocene.publishedVersio

Tribology of Wire Arc Spray Coatings under the Influence of Regenerative Fuels

In order to further optimize the efficiency of today’s internal combustion engines, specific coatings are used on functional surfaces to reduce internal engine friction and wear. In the current research project, oxymethylene ether (OME) is discussed because it is CO2 neutral and has a strong soot-reducing effect as a fuel or fuel additive. In some operational regimes of the internal combustion engine a dilution of engine oil by fuel must be assumed. In this paper, the frictional contact between piston ring and cylinder raceway is modelled using a pin-on-disk tribometer and the friction and wear behavior between a diamond-like carbon coating (DLC) and a thermal spray coating is characterized. The wear of the spray layer could be continuously detected by radionuclide technology (RNT). With the aid of photoelectron spectroscopic measurements (XPS), the steel thermal spray coating was chemically analyzed before and after the tribometer tests and the oxidative influence of OME was investigated. In addition, confocal microscopy was used to assess the topographies of the specimens. The measurements showed that the addition of OME to the lubricant reduced the viscosity and load-bearing capacity of the lubricating film, which led to an increase in the coefficient of friction. While almost no wear on the pin could be detected at 10% OME, the first visible material removal occurs at an OME content of 20% and the layer delaminated at 30% OME. The evaluation of the RNT wear tests showed that both the tests with engine oil and with engine oil plus 20% OME achieved very low wear rates. No corrosion of the thermal spray coating could be detected by XPS. Only the proportion of engine oil additives in the friction track increased with increasing OME concentration

Typical dimension of the graph of certain functions.

Most functions from the unit interval to itself have a graph with. Hausdorff and lower entropy dimension 1 and upper entropy dimension 2. The same holds for several other Baire spaces of functions. In this paper it will be proved that this is the case also in the spaces of all mappings that are Lebesque measurable, Borel measurable, integrable in the Riemann sense, continuous, uniform distribution preserving (and continuous)

An Efficient Way to Screen Inhibitors of Energy-Coupling Factor (ECF) Transporters in a Bacterial Uptake Assay

Herein, we report a novel whole-cell screening assay using Lactobacillus casei as a model microorganism to identify inhibitors of energy-coupling factor (ECF) transporters. This promising and underexplored target may have important pharmacological potential through modulation of vitamin homeostasis in bacteria and, importantly, it is absent in humans. The assay represents an alternative, cost-effective and fast solution to demonstrate the direct involvement of these membrane transporters in a native biological environment rather than using a low-throughput in vitro assay employing reconstituted proteins in a membrane bilayer system. Based on this new whole-cell screening approach, we demonstrated the optimization of a weak hit compound (2) into a small molecule (3) with improved in vitro and whole-cell activities. This study opens the possibility to quickly identify novel inhibitors of ECF transporters and optimize them based on structure–activity relationships