194 research outputs found

    Extending database accelerators for data transformations and predictive analytics

    Get PDF
    The IBM DB2 Analytics Accelerator (IDAA) integrates the strong OLTP capabilities of DB2 for z/OS with very fast processing of OLAP workloads using Netezza technology. The accelerator is attached to DB2 as analytical process- ing resource { completely transparent for user applications. But all data modi_cations must be carried out by DB2 and are replicated to the accelerator internally. However, this behavior is not optimized for ELT processing and predic- tive analytics or data mining workloads where multi-staged data transformations are involved. We present our work for extending IDAA with accelerator-only tables, which enable direct data transformations without any necessary interven- tions by DB2. Further, we present a framework for executing arbitrary in-database analytics operations on the accelerator while ensuring data governance aspects like privilege man- agement on DB2 and allowing to ingest data from any other source directly to the accelerator to enrich analytics e. g., with social media data. The evolutionary framework design maintains compatibility with existing infrastructure and ap- plications, a must-have for the majority of customers, while allowing complex analytics beyond read-only reporting

    Spectral signature of quantum spin diffusion in dimensions d = 1, 2, and 3

    Get PDF
    The spectral densities of dynamical spin autocorrelation functions at infinite temperature are studied for the S = 1/2 XXZ model (with exchange couplings Jx = Jy = J,Jz) on the linear chain, the square lattice, and the simple cubic lattice. The low-frequency behavior of a given spectral density is inferred from certain characteristic properties of its continued-fraction coefficients as determined from computed frequency moments. The analysis yields estimates for the Jz/J dependence of the infrared-singularity exponent. In the d = 1 case, the exponent for spin fluctuations perpendicular to the O(2) symmetry axis responds sensitively as the anisotropy parameter sweeps across the O(3) symmetry point Jz/J = 1, while the exponent for the parallel fluctuations shows little variation. In the cases d = 2 and d = 3 the same observations are made for autocorrelation functions of aggregate spins in chains and lattice planes, respectively

    Klimaneutraler Acker- und Gemüsebau - Auswirkungen von reduzierter Bodenbearbeitung und Gründüngungen auf Bodenfruchtbarkeit, Klima und Ökonomie – bisherige Erkenntnisse und aktuelle Versuche

    Get PDF
    Die Landwirtschaft trägt weltweit mit 12–32 Prozent zum Klimawandel bei. Hauptquellen sind der Methanausstoss der Wiederkäuer, der CO2-Verbrauch für die Herstellung von Düngern und Pestiziden, die Abholzung von Wäldern für den Ackerbau und Weideflächen sowie die Bodenerosion. Auch der Einsatz des Pflugs verbraucht viel Energie, verstärkt den Abbau von Humus und belastet somit das Klima. Gemäss bisherigen Untersuchungen benötigt die biologische Landwirtschaft schon heute mit den gängigen Methoden weniger Energie als die konventionelle Bewirtschaftung. Im DOK-Versuch zum Beispiel verbrauchen die Bioverfahren 20 Prozent weniger Energie pro Ertragseinheit. Dies macht den Biolandbau zwar klimafreundlicher, aber noch nicht klimaneutral. Durch die Anwendung reduzierter Bodenbearbeitungsverfahren und den vermehrten Anbau von Stickstoff fixierenden Gründüngungspflanzen liessen sich der Energiebedarf und der CO2-Ausstoss nochmals deutlich senken und die Erträge steigern

    Cavalier King Charles Spaniels with Chiari-like malformation and Syringomyelia have increased variability of spatio-temporal gait characteristics

    Get PDF
    Abstract Background Chiari-like malformation in the Cavalier King Charles Spaniel is a herniation of the cerebellum and brainstem into or through the foramen magnum. This condition predisposes to Syringomyelia; fluid filled syrinxes within the spinal cord. The resulting pathology in spinal cord and cerebellum create neuropathic pain and changes in gait. This study aims to quantify the changes in gait for Cavalier King Charles Spaniel with Chiari-like malformation and Syringomyelia. Methods We compared Cavalier King Charles Spaniel with Chiari-like malformation with (n = 9) and without (n = 8) Syringomyelia to Border Terriers (n = 8). Two video cameras and manual tracking was used to quantify gait parameters. Results and conclusions We found a significant increase in coefficient of variation for the spatio-temporal characteristics and ipsilateral distance between paws and a wider base of support in the thoracic limbs but not in the pelvic limbs for Cavalier King Charles Spaniels compared with the border terrier

    Hadron Production in Diffractive Deep-Inelastic Scattering

    Get PDF
    Characteristics of hadron production in diffractive deep-inelastic positron-proton scattering are studied using data collected in 1994 by the H1 experiment at HERA. The following distributions are measured in the centre-of-mass frame of the photon dissociation system: the hadronic energy flow, the Feynman-x (x_F) variable for charged particles, the squared transverse momentum of charged particles (p_T^{*2}), and the mean p_T^{*2} as a function of x_F. These distributions are compared with results in the gamma^* p centre-of-mass frame from inclusive deep-inelastic scattering in the fixed-target experiment EMC, and also with the predictions of several Monte Carlo calculations. The data are consistent with a picture in which the partonic structure of the diffractive exchange is dominated at low Q^2 by hard gluons.Comment: 16 pages, 6 figures, submitted to Phys. Lett.

    Low Q^2 Jet Production at HERA and Virtual Photon Structure

    Get PDF
    The transition between photoproduction and deep-inelastic scattering is investigated in jet production at the HERA ep collider, using data collected by the H1 experiment. Measurements of the differential inclusive jet cross-sections dsigep/dEt* and dsigmep/deta*, where Et* and eta* are the transverse energy and the pseudorapidity of the jets in the virtual photon-proton centre of mass frame, are presented for 0 < Q2 < 49 GeV2 and 0.3 < y < 0.6. The interpretation of the results in terms of the structure of the virtual photon is discussed. The data are best described by QCD calculations which include a partonic structure of the virtual photon that evolves with Q2.Comment: 20 pages, 5 Figure

    Energy Flow in the Hadronic Final State of Diffractive and Non-Diffractive Deep-Inelastic Scattering at HERA

    Get PDF
    An investigation of the hadronic final state in diffractive and non--diffractive deep--inelastic electron--proton scattering at HERA is presented, where diffractive data are selected experimentally by demanding a large gap in pseudo --rapidity around the proton remnant direction. The transverse energy flow in the hadronic final state is evaluated using a set of estimators which quantify topological properties. Using available Monte Carlo QCD calculations, it is demonstrated that the final state in diffractive DIS exhibits the features expected if the interaction is interpreted as the scattering of an electron off a current quark with associated effects of perturbative QCD. A model in which deep--inelastic diffraction is taken to be the exchange of a pomeron with partonic structure is found to reproduce the measurements well. Models for deep--inelastic epep scattering, in which a sizeable diffractive contribution is present because of non--perturbative effects in the production of the hadronic final state, reproduce the general tendencies of the data but in all give a worse description.Comment: 22 pages, latex, 6 Figures appended as uuencoded fil

    A Search for Selectrons and Squarks at HERA

    Get PDF
    Data from electron-proton collisions at a center-of-mass energy of 300 GeV are used for a search for selectrons and squarks within the framework of the minimal supersymmetric model. The decays of selectrons and squarks into the lightest supersymmetric particle lead to final states with an electron and hadrons accompanied by large missing energy and transverse momentum. No signal is found and new bounds on the existence of these particles are derived. At 95% confidence level the excluded region extends to 65 GeV for selectron and squark masses, and to 40 GeV for the mass of the lightest supersymmetric particle.Comment: 13 pages, latex, 6 Figure

    BRCA1 tumours correlate with a HIF-1α phenotype and have a poor prognosis through modulation of hydroxylase enzyme profile expression

    Get PDF
    BACKGROUND: There are limited data regarding the hypoxia pathway in familial breast cancers. We therefore performed a study of hypoxic factors in BRCA1, BRCA2 and BRCAX breast cancers. METHODS: Immunoperoxidase staining for HIF-1alpha, PHD1, PHD2, PHD3, VEGF and FIH was carried out in 125 (38 BRCA1, 33 BRCA2 and 54 BRCAX) breast carcinomas. These were correlated with clinicopathological parameters and the intrinsic breast cancer phenotypes. RESULTS: BRCA1 tumours correlated with positivity for HIF-1alpha (P=0.008) and negativity for PHD3 (P=0.037). HIF-1alpha positivity (P=0.001), PHD3 negativity (P=0.037) and nuclear FIH negativity (P=0.011) was associated with basal phenotype. HIF-1alpha expression correlated with high tumour grade (P=0.009), negative oestrogen receptor (ER) status (P=0.001) and the absence of lymph node metastasis (P=0.028). Nuclear FIH expression and PHD3 correlated with positive ER expression (P=0.024 and P=0.035, respectively). BRCA1 cancers with positive HIF-1alpha or cytoplasmic FIH had a significantly shorter relapse-free survival (P=0.007 and P=0.049, respectively). CONCLUSIONS: The aggressive nature of BRCA1 and basal-type tumours may be partly explained by an enhanced hypoxic drive and hypoxia driven ER degradation because of suppressed PHD and aberrantly located FIH expression. This may have important implications, as these tumours may respond to compounds directed against HIF-1alpha or its downstream targets

    Decay and Fission Hindrance of Two- and Four-Quasiparticle K Isomers in (254)Rf

    Get PDF
    Two isomers decaying by electromagnetic transitions with half-lives of 4.7(1.1) and 247(73)μs have been discovered in the heavy Rf254 nucleus. The observation of the shorter-lived isomer was made possible by a novel application of a digital data acquisition system. The isomers were interpreted as the Kπ=8-, ν2(7/2+[624],9/2-[734]) two-quasineutron and the Kπ=16+, 8-ν2(7/2+[624],9/2-[734])⊗ - 8-π2(7/2-[514],9/2+[624]) four-quasiparticle configurations, respectively. Surprisingly, the lifetime of the two-quasiparticle isomer is more than 4 orders of magnitude shorter than what has been observed for analogous isomers in the lighter N=150 isotones. The four-quasiparticle isomer is longer lived than the Rf254 ground state that decays exclusively by spontaneous fission with a half-life of 23.2(1.1)μs. The absence of sizable fission branches from either of the isomers implies unprecedented fission hindrance relative to the ground state
    corecore