Nucleic Acid Ligands Based on Carbohydrates

Sequence-specific nucleic acid ligands are important tools in chemistry and molecular biology and are thought to possess a considerable pharmaceutical potential. An overview of the structurally and mechanistically diverse approaches in the field with an emphasis on carbohydrates will be presented. Carbohydrates are just beginning to emerge as a novel class of nucleic acid binding compounds. The detailed study of the factors affecting the site-selectivity of some recently discovered antitumor antibiotics, e.g. calicheamicin, has shed a new light on the role thatoligosaccharides may play in nucleic acid recognition. Understanding these factors may aid in the rational design of novel nucleic acid ligands and their therapeutic application

L-Sol : Gebäudeenergie-Konzept basierend auf PVT-Modulen

Das System L-Sol zeigt eine höhere System-Jahresarbeitszahl und ähnliche Gesamtkosten wie ein Luft-Wasser-Wärmepumpen-System. Es verursacht aber keine Lärmemissionen und lässt sich gut optimieren bezüglich PV-Eigenverbrauch

«L-Sol» : effizientes Heizsystem mit PVT und Wärmepumpe

Das L-Sol Heizsystem mit PVT und Wärmepumpe versorgt EFH effizienter mit Wärme als ein System mit Luft-Wasser-Wärmepumpe. Erweiterte Regelstrategien erlauben eine weitere Reduktion des Strombezugs aus dem Netz um rund 23 %

Mechanische Unkrautregulierung in der Saatreihe von Soja

Organic cropping of soya beans mainly depends on the successful control of weeds. Hoeing in between the crop rows can be effective but the mechanical control of weeds within the crop row is difficult. Objective of this study was to investigate the effect of three machines and two combinations thereof to control two model weeds seeded directly in the crop row of soya bean. Reduction of the soil cover (%) in the crop row was evaluated after the means were applied and compared to the control treatment (hoeing between the crop rows). Results of two experiments conducted in 2007 and 2008 show that soil cover of companion plants within the crop row can be reduced up to 70 % when compared to the control treatment. Before best treatments can be recommended for the farmers, large-scale tests have to be conducted in order to improve the use of these means to keep the impact on the main crop as low as possible

Eignung von neuen Sommerölleinsorten für den Ökolandbau im Schweizer Mittelland

Oil flax was cropped in Switzerland in former times but seldom today. To investigate new varieties with respect to their agronomic performance and suitability for the production of cold-pressed oil, 15 varieties of spring flax were tested in the years 2005-2007 at one site. They were sown in small plots with four replicates and managed according the rules of Swiss organic farming. Averaged over the years, seed yield of the varieties ranged from 1.4 - 1.9 t/ha. Pressure of pests and diseases were generally low and weeds were controlled successfully by mechanical means. In order to recommend flax varieties for the production of oil, oil quality aspects need to be considered and investigated carefully

L-Sol – heating system with PVT-collectors as single heat source for a brine-water heat pump

The building sector has a huge potential for reducing greenhouse gas emission without the need of a higher sufficiency. The key is to build and retrofit buildings with good envelopes as well as choosing efficient heating systems. A heating system with a brine-water heat pump and PVT collectors as single heat source is suggested here as an alternative to an air-water heat pump system for single family houses. In the system simulations performed, the PVT-heat pump System ("L-Sol") is more efficient than an air-water heat pump system and still affordable. As the System L-Sol produces heat and electricity on the same area it saves space, disadvantages like noise emission of air-water heat pumps or costly drilling of bore holes are omitted. The system has been optimized in terms of efficiency by testing different dimensioning of the components and regarding the grid purchase by optimizing the system control

Design of an N^7-Glycosylated Purine Nucleoside for Recognition of GC Base Pairs by Triple Helix Formation

Pyrimidine oligodeoxyribonucleotides bind in the major groove of DNA parallel to the purine Watson-Crick strand by formation of specific hydrogen bonds between thymine and adenine (T•AT triplet) and protonated cytosine and guanine (C+GC triplet) on the Hoogsteen face of the purine base. Alternatively, purine oligodeoxyribonucleotides bind in an antiparallel orientation relative to the purine Watson-Crick strand by formation of G•GC and A•AT triplets. The prerequisite protonation of cytosine in C+GC triplets leads to a considerable pH dependence in the binding affinity of C-containing oligodeoxyribonucleotides (Figure 1). Substitution of 5-methylcytosine (^mC) for cytosine results in increased binding affinities near physiological pH. In an attempt to eliminate the necessity for protonation, recent efforts have been directed toward the synthesis of nonnatural nucleosides which display the hydrogen bonding functionality of protonated cytosine

Using deep generative neural networks to account for model errors in Markov chain Monte Carlo inversion

Most geophysical inverse problems are non-linear and rely upon numerical forward solvers involving discretization and simplified representations of the underlying physics. As a result, forward modelling errors are inevitable. In practice, such model errors tend to be either completely ignored, which leads to biased and over-confident inversion results, or only partly taken into account using restrictive Gaussian assumptions. Here, we rely on deep generative neural networks to learn problem-specific low-dimensional probabilistic representations of the discrepancy between high-fidelity and low-fidelity forward solvers. These representations are then used to probabilistically invert for the model error jointly with the target geophysical property field, using the computationally cheap, low-fidelity forward solver. To this end, we combine a Markov chain Monte Carlo (MCMC) inversion algorithm with a trained convolutional neural network of the spatial generative adversarial network (SGAN) type, whereby at each MCMC step, the simulated low-fidelity forward response is corrected using a proposed model-error realization. Considering the crosshole ground-penetrating radar traveltime tomography inverse problem, we train SGAN networks on traveltime discrepancy images between: (1) curved-ray (high fidelity) and straight-ray (low fidelity) forward solvers; and (2) finite-difference-time-domain (high fidelity) and straight-ray (low fidelity) forward solvers. We demonstrate that the SGAN is able to learn the spatial statistics of the model error and that suitable representations of both the subsurface model and model error can be recovered by MCMC. In comparison with inversion results obtained when model errors are either ignored or approximated by a Gaussian distribution, we find that our method has lower posterior parameter bias and better explains the observed traveltime data. Our method is most advantageous when high-fidelity forward solvers involve heavy computational costs and the Gaussian assumption of model errors is inappropriate. Unstable MCMC convergence due to non-linearities introduced by our method remain a challenge to be addressed in future work

Probing the solution space of an EM inversion problem with a genetic algorithm

SUMMARY In an inversion for the subsurface conductivity distribution using frequency-domain Controlled-Source Electromagnetic data, various amounts of horizontal components may be included. We investigate which combination of components are best suited to invert for a vertical transverse isotropic (VTI) subsurface. We do this by probing the solutionspace using a genetic algorithm. We found, by studying a simple horizontally layered medium, that if only electric data are used, either the horizontal or the vertical conductivity of a layer can be estimated properly, but not both. Including the crossline electric field does not add additional information. In contrast, including the two horizontal magnetic components along with the two horizontal electric components allows to retrieve a better estimate of some of the VTI parameters. For an isotropic subsurface, the electric field is sufficient to invert for the subsurface conductivity