Visual Analysis of Microarray Data from Bioinformatics Applications

We present a new application designed for the visual exploration of microarray data.It is based on an extension and adaption of parallel coordinates to support the visual exploration of large and high-dimensional datasets. In particular, we investigate the visual analysis of gene-expression data as generated by microarray experiments. We combine refined visual exploration with statistical methods to a visual analytics approach, which proved to be particularly successful in this application domain. We will demonstrate the usefulness on several multidimensional gene-expression datasets from different bioinformatics applications

A Transient Expression of Prospero Promotes Cell Cycle Exit of Drosophila Postembryonic Neurons through the Regulation of Dacapo

Cell proliferation, specification and terminal differentiation must be precisely coordinated during brain development to ensure the correct production of different neuronal populations. Most Drosophila neuroblasts (NBs) divide asymmetrically to generate a new NB and an intermediate progenitor called ganglion mother cell (GMC) which divides only once to generate two postmitotic cells called ganglion cells (GCs) that subsequently differentiate into neurons. During the asymmetric division of NBs, the homeodomain transcription factor PROSPERO is segregated into the GMC where it plays a key role as cell fate determinant. Previous work on embryonic neurogenesis has shown that PROSPERO is not expressed in postmitotic neuronal progeny. Thus, PROSPERO is thought to function in the GMC by repressing genes required for cell-cycle progression and activating genes involved in terminal differentiation. Here we focus on postembryonic neurogenesis and show that the expression of PROSPERO is transiently upregulated in the newly born neuronal progeny generated by most of the larval NBs of the OL and CB. Moreover, we provide evidence that this expression of PROSPERO in GCs inhibits their cell cycle progression by activating the expression of the cyclin-dependent kinase inhibitor (CKI) DACAPO. These findings imply that PROSPERO, in addition to its known role as cell fate determinant in GMCs, provides a transient signal to ensure a precise timing for cell cycle exit of prospective neurons, and hence may link the mechanisms that regulate neurogenesis and those that control cell cycle progression in postembryonic brain development

Evaluation of a Bundling Technique for Parallel Coordinates

We describe a technique for bundled curve representations in parallel-coordinates plots and present a controlled user study evaluating their effectiveness. Replacing the traditional C^0 polygonal lines by C^1 continuous piecewise Bezier curves makes it easier to visually trace data points through each coordinate axis. The resulting Bezier curves can then be bundled to visualize data with given cluster structures. Curve bundles are efficient to compute, provide visual separation between data clusters, reduce visual clutter, and present a clearer overview of the dataset. A controlled user study with 14 participants confirmed the effectiveness of curve bundling for parallel-coordinates visualization: 1) compared to polygonal lines, it is equally capable of revealing correlations between neighboring data attributes; 2) its geometric cues can be effective in displaying cluster information. For some datasets curve bundling allows the color perceptual channel to be applied to other data attributes, while for complex cluster patterns, bundling and color can represent clustering far more clearly than either alone

iHAT: interactive Hierarchical Aggregation Table for Genetic Association Data

In the search for single-nucleotide polymorphisms which influence the observable phenotype, genome wide association studies have become an important technique for the identification of associations between genotype and phenotype of a diverse set of sequence-based data. We present a methodology for the visual assessment of single-nucleotide polymorphisms using interactive hierarchical aggregation techniques combined with methods known from traditional sequence browsers and cluster heatmaps. Our tool, the interactive Hierarchical Aggregation Table (iHAT), facilitates the visualization of multiple sequence alignments, associated metadata, and hierarchical clusterings. Different color maps and aggregation strategies as well as filtering options support the user in finding correlations between sequences and metadata. Similar to other visualizations such as parallel coordinates or heatmaps, iHAT relies on the human pattern-recognition ability for spotting patterns that might indicate correlation or anticorrelation. We demonstrate iHAT using artificial and real-world datasets for DNA and protein association studies as well as expression Quantitative Trait Locus data

Alkali metal dithiocarbamato carboxylates (DTCCs) – synthesis, properties, and crystal structures

A series of alkali metal salts of dithiocarbamate‐substituted carboxylate (DTCC) anions were prepared by reaction of the parent amino acids with carbon disulfide and an alkali metal hydroxide. The target compounds, which were isolated in anhydrous form or as hydrates, were extensively characterized by elemental analyses, IR and NMR spectroscopy, thermal analyses, cyclic voltammetry, and single‐crystal X‐ray diffraction. The isolated compounds are more or less hygroscopic and display a varying dehydratization and decomposition behavior upon heating. The assumed degradation of the DTCC scaffold was found to depend on the substitution pattern as well as on the alkali metal counterion, and covers a range between 200 and 340 °C. In aqueous solution, the DTCC anions show irreversible electrochemical oxidations, where the corresponding redox potentials are governed by the substitution pattern of the nitrogen atom. Single‐crystal structural analyses of sodium and potassium derivatives revealed that these compounds exist as two‐ or three‐dimensional coordination polymers in the solid state, with the alkali‐metal ions adopting typical irregular coordination environments with coordination numbers of six or higher

Forty Years after the Discovery of Its Nucleolytic Activity: [Cu(phen)(2)](2+) Shows Unattended DNA Cleavage Activity upon Fluorination

[Cu(phen)(2)](2+) (phen=1,10-phenanthroline) is the first and still one of the most efficient artificial nucleases. In general, when the phen ligand is modified, the nucleolytic activity of its Cu-II complex is significantly reduced. This is most likely due to higher steric bulk of such ligands and thus lower affinity to DNA. Cu-II complexes with phen ligands having fluorinated substituents (F, CF3, SF5, SCF3) surprisingly showed excellent DNA cleavage activity-in contrast to the unsubstituted [Cu(phen)(2)](2+)-in the absence of the otherwise required classical, bioabundant external reducing agents like thiols or ascorbate. This nucleolytic activity correlates well with the half-wave potentials E-1/2 of the complexes. Cancer cell studies show cytotoxic effects of all complexes with fluorinated ligands in the low mu m range, whereas they were less toxic towards healthy cells (fibroblasts)

Bedarf an regionalen Produkten im inhabergeführten Lebensmitteleinzelhandel - Befragungsergebnisse: Befragung in den Direktionsbezirken Leipzig, Dresden und Chemnitz

Der Bericht gibt die Ergebnisse einer Befragung von 40 Einzelhändlern in Sachsen wieder. Er zeigt deren Bedarf an bio- und regionalen Lebensmitteln. Adressaten sind direktvermarktende Landwirte, Lebensmittelhersteller sowie deren Berater und Organisationen. Redaktionsschluss: 31.07.202