Supermartingales in prediction with expert advice

The paper applies the method of defensive forecasting, based on the use of game-theoretic supermartingales, to prediction with expert advice. In the traditional setting of a countable number of experts and a finite number of outcomes, the Defensive Forecasting Algorithm is very close to the well-known Aggregating Algorithm. Not only the performance guarantees but also the predictions are the same for these two methods of fundamentally different nature. The paper also discusses a new setting where the experts can give advice conditional on the learner’s future decision. Both the algorithms can be adapted to the new setting and give the same performance guarantees as in the traditional setting. Finally, an application of defensive forecasting to a setting with several loss functions is outlined.     

Influence of yeast strain on aromatic profile of Gewürztraminer wine

Three selected autochthonous and one commercial Saccharomyces cerevisiae strains used as starters for fermentation of the same Gewürztraminer must were compared in terms of their influence on primary and secondary aroma of wine. At the same testing conditions, each strain S. cerevisiae produced individual metabolites in different concentrations and combinations which significantly influenced resulting wine flavour. Higher concentrations of 2-phenylethanol and cis-rose oxide, associated with S. cerevisiae TC-NAX-A, considerably distinguished this strain from the others. Occurrence of these VOCs has important influence on sweet rose-like flavour typical for Gewürztraminer wine. This paper deals with the characterization of chemical substances that directly affect the primary varietal aroma of Gewürztraminer wine, while looking for a tool to produce an original and attractive product in form of suitable autochthonous strain S. cerevisiae.     

Kaiso Regulates DNA Methylation Homeostasis

Gain and loss of DNA methylation in cells is a dynamic process that tends to achieve an equilibrium. Many factors are involved in maintaining the balance between DNA methylation and demethylation. Previously, it was shown that methyl-DNA protein Kaiso may attract NCoR, SMRT repressive complexes affecting histone modifications. On the other hand, the deficiency of Kaiso resulted in reduced methylation of ICR in H19/Igf2 locus and Oct4 promoter in mouse embryonic fibroblasts. However, nothing is known about how Kaiso influences DNA methylation at the genome level. Here we show that deficiency of Kaiso led to whole-genome hypermethylation, using Kaiso deficient human renal cancer cell line obtained via CRISPR/CAS9 genome editing. However, Kaiso serves to protect genic regions, enhancers, and regions with a low level of histone modifications from demethylation. We detected hypomethylation of binding sites for Oct4 and Nanog in Kaiso deficient cells. Kaiso immunoprecipitated with de novo DNA methyltransferases DNMT3a/3b, but not with maintenance methyltransferase DNMT1. Thus, Kaiso may attract methyltransferases to surrounding regions and modulate genome methylation in renal cancer cells apart from being methyl DNA binding protein.     

Nanocomposites consisting of titanium dioxide nanoparticles and oligonucleotides

The use of various nanoparticles is a promising way to solve the current problem of drug delivery in medicine and biology. Nanocomposites consisting of titanium dioxide and oligonucleotides noncovalently attached to nanoparticles through the polylysine linker (TiO2 x PL-DNA) have been designed to deliver of DNA fragments into cells. Three forms of TiO2 nanoparticles (amorphous, anatase, and brookite) were used for construction of nanocomposites. The size, morphology, and chemical composition of TiO2 nanoparticles and TiO2 x PL-DNA nanocomposites were characterized. DNA fragments in the proposed nanocomposites were shown to retain their ability to form complementary complexes. TiO2 x PL-DNA nanocomposites independently on the form of nanoparticles were shown by confocal microscopy to penetrate into HeLa cells without any transfection agents and physical impact. The presented type of nanocomposites can be applied in the thriving technology of drug delivery to achieve high therapeutic and biological efficacy.     

Reduction in database search space by utilization of amino acid composition information from electron transfer dissociation and higher-energy collisional dissociation mass spectra

With high-mass accuracy and consecutively obtained electron transfer dissociation (ETD) and higher-energy collisional dissociation (HCD) tandem mass spectrometry (MS/MS), reliable (≥97%) and sensitive fragment ions have been extracted for identification of specific amino acid residues in peptide sequences. The analytical benefit of these specific amino acid composition (AAC) ions is to restrict the database search space and provide identification of peptides with higher confidence and reduced false negative rates. The 6706 uniquely identified peptide sequences determined with a conservative Mascot score of >30 were used to characterize the AAC ions. The loss of amino acid side chains (small neutral losses, SNLs) from the charge reduced peptide radical cations was studied using ETD. Complementary AAC information from HCD spectra was provided by immonium ions. From the ETD/HCD mass spectra, 5162 and 6720 reliable SNLs and immonium ions were successfully extracted, respectively. Automated application of the AAC information during database searching resulted in an average 3.5-fold higher confidence level of peptide identification. In addition, 4% and 28% more peptides were identified above the significance level in a standard and extended search space, respectively.     

CD82 and Gangliosides Tune CD81 Membrane Behavior

Tetraspanins are a family of transmembrane proteins that form a network of protein–protein interactions within the plasma membrane. Within this network, tetraspanin are thought to control the lateral segregation of their partners at the plasma membrane through mechanisms involving specific lipids. Here, we used a single molecule tracking approach to study the membrane behavior of tetraspanins in mammary epithelial cells and demonstrate that despite a common overall behavior, each tetraspanin (CD9, CD81 and CD82) has a specific signature in terms of dynamics. Furthermore, we demonstrated that tetraspanin dynamics on the cell surface are dependent on gangliosides. More specifically, we found that CD82 expression increases the dynamics of CD81 and alters its localization at the plasma membrane, this has no effect on the behavior of CD9. Our results provide new information on the ability of CD82 and gangliosides to differentially modulate the dynamics and organization of tetraspanins at the plasma membrane and highlight that its lipid and protein composition is involved in the dynamical architecture of the tetraspanin web. We predict that CD82 may act as a regulator of the lateral segregation of specific tetraspanins at the plasma membrane while gangliosides could play a crucial role in establishing tetraspanin-enriched areas.     

Einfluß von Werkzeugstoff und seiner Wärmebehandlung auf das Schneiden von Feinblech

An 21 verschieden wärmebehandelten Werkzeugen aus den sieben Werkzeugstählen X 210 Cr 12 mit rd. 2,0% C und 11,0% Cr, X 210 CrW 12 mit rd. 2,1% C, 11,5% Cr und 0,7% W, X 166 CrMoV 12 mit rd. 1,5% C, l2,4% Cr, 0,7% Mo, 0,4% V und 0,4% W, X100 CrMoV 51 mit rd. 1,0% C, 5,3% Cr, 1,1% Mo und 0,3% V, 105 WCr 6 mit rd. 1,0% C, 1,0% Mn, 1,1% Cr und 1,2% W, 90 MnV 8 mit rd. 0,9% C, 1,7% Mn, 0,1% Cr und 0,1% V sowie S 6-5-2 mit rd. 0,86% C, 4,0% Cr, 4,9% Mo, 1,7% V und 6,3% W Untersuchung ihres Verschleiβes und der Gratbildung in Abhängigkeit von der Schnittzahl beim Schneiden von zwei Feinblechsorten auf einer Viersäulen-Schnelläufer-Presse. Abhängigkeit des Werkzeugverschleiβes und der Gratbildung von der Verschleiβ form. Einfluβ des Karbidmengenanteils im Gefüge der Werkzeuge auf den Verschleiβ.     

Ultralow Dispersion Multicomponent Thin‐Film Chalcogenide Glass for Broadband Gradient‐Index Optics

A novel photothermal process to spatially modulate the concentration of sub‐wavelength, high‐index nanocrystals in a multicomponent Ge‐As‐Pb‐Se chalcogenide glass thin film resulting in an optically functional infrared grating is demonstrated. The process results in the formation of an optical nanocomposite possessing ultralow dispersion over unprecedented bandwidth. The spatially tailored index and dispersion modification enables creation of arbitrary refractive index gradients. Sub‐bandgap laser exposure generates a Pb‐rich amorphous phase transforming on heat treatment to high‐index crystal phases. Spatially varying nanocrystal density is controlled by laser dose and is correlated to index change, yielding local index modification to ≈+0.1 in the mid‐infrared.     

DECISION SUPPORT WITH LOGICAL AND FUZZY PETRI NETS

Modern knowledge representation is a very dynamic domain because of continuous research and development. This paper presents Logical Petri Nets (LPNs) and Fuzzy Petri Nets (FPNs) as models for knowledge representation. It is shown that knowledge propagation, described using logical and fuzzy Petri nets, terminates in a unique stable state. Based on this result, the paper introduces an algorithm for knowledge propagation in decision support systems.     

How to Guard a Graph?

We initiate the study of the algorithmic foundations of games in which a set of cops has to guard a region in a graph (or digraph) against a robber. The robber and the cops are placed on vertices of the graph; they take turns in moving to adjacent vertices (or staying). The goal of the robber is to enter the guarded region at a vertex with no cop on it. The problem is to find the minimum number of cops needed to prevent the robber from entering the guarded region. The problem is highly non-trivial even if the robber’s or the cops’ regions are restricted to very simple graphs. The computational complexity of the problem depends heavily on the chosen restriction. In particular, if the robber’s region is only a path, then the problem can be solved in polynomial time. When the robber moves in a tree (or even in a star), then the decision version of the problem is NP-complete. Furthermore, if the robber is moving in a directed acyclic graph, the problem becomes PSPACE-complete.