Optimization of Computationally and I/O Intense Patterns in Electronic Structure and Machine Learning Algorithms

Development of scalable High-Performance Computing (HPC) applications is already a challenging task even in the pre-Exascale era. Utilization of the full potential of (near-)future supercomputers will most likely require the mastery of massively parallel heterogeneous architectures with multi-tier persistence systems, ideally in fault tolerant mode. With the change in hardware architectures HPC applications are also widening their scope to `Big data' processing and analytics using machine learning algorithms and neural networks. In this work, in cooperation with the INTERTWinE FET-HPC project, we demonstrate how the GASPI (Global Address Space Programming Interface) programming model helps to address these Exascale challenges on examples of tensor contraction, K-means and Terasort algorithms

Molecular analysis of photosynthetic picoeukaryote community structure along an Arabian Sea transect

We developed oligonucleotide probes, based on plastid 16S ribosomal DNA (rDNA) sequences, to target 10 different algal classes (Chlorarachniophyceae, Chrysophyceae, Cryptophyceae, Eustigmatophyceae, Pavlovophyceae, Pelagophyceae, Pinguiophyceae, Prasinophyceae [clade VI], Prymnesiophyceae, and Trebouxiophyceae), for use with dot blot hybridization technology. These class-specific probes were then used to investigate the community structure of photosynthetic picoeukaryotes (< 3 mu m) along a transect in the Arabian Sea during September 2001, using hybridization to plastid 16S rDNA polymerase chain reaction amplicons. The transect ranged from oligotrophic open-ocean waters, just south of the Equator, through mesotrophic and eutrophic waters toward the north coast of Oman, crossing a region of monsoonal upwelling off the Omani northeast coast. Photosynthetic picoeukaryotes in the surface-mixed layer (SML) and deep chlorophyll maximum ranged from 1.0 x 10(3) cells mL(-1) in southern oligotrophic waters to almost 30 x 10(3) cells mL(-1) at the region of upwelling. Chrysophytes were abundant along most of the transect throughout much of the euphotic zone. Prymnesiophytes were abundant in surface waters along much of the transect. By contrast, trebouxiophytes were confined to deeper waters, below the SML. Pelagophytes were found in surface waters that were more mesotrophic, whereas cryptophytes were only detected in the more nutrient-rich waters at the northern end of the transect, between depths of 20-30 in. Pinguiophytes were also detected, but only in the warm surface waters off the north coast of Oman. Chlorarachniophytes, eustigmatophytes, pavlovophytes, and clade VI prasinophytes were essentially below detection limits for the entire transect

On the Electronic Structure of mer,trans−[RuCl3(1H−indazole)2(NO)]mer,trans-[RuCl_{3}(1 H -indazole)_{2}(NO)], a Hypothetical Metabolite of the Antitumor Drug Candidate KP1019: An Experimental and DFT Study

The study reported herein focused on the electronic structure of the {Ru(NO)}6 fragment and characterization of the oxidation state of ruthenium in mer,trans-[RuCl3(Hind)2(NO)] (1; Hind = 1H-indazole) resulting from the reaction of mer,trans-[RuCl3(H2O)(Hind)2] (2) with NO in acetone or solid-state Anderson rearrangement of (H2ind)2[RuCl5(NO)] at 180 °C. The results of X-ray diffraction, 1H, 13C, and 15N NMR, EPR, IR, and UV/Vis spectroscopy, cyclic voltammetry, magnetic susceptibility, and XANES/EXAFS as well as theoretical data have been critically analyzed. The localized orbitals, domain-averaged Fermi holes, frontier orbitals, Mulliken population, and quantum theory of atoms-in-molecules (QTAIM) analyses are presented. In addition, mer,trans-[RuIIICl3(H2O)(Hind)2] (2) and trans-[RuIICl2(Hind)4] (3) were experimentally and theoretically investigated as reference compounds. A complete active space SCF calculation was performed to estimate the extent of antiferromagnetic spin–spin coupling in 1. We found that the closed-shell structure {RuIII(NO)0}6 fits better to the physical/spectroscopic properties of 1, although {RuII(NO)+}6 is formally still suitable for describing the oxidation state of Ru in this entit