Using NSPT for the Removal of Hypercubic Lattice Artifacts

The treatment of hypercubic lattice artifacts is essential for the calculation of non-perturbative renormalization constants of RI-MOM schemes. It has been shown that for the RI'-MOM scheme a large part of these artifacts can be calculated and subtracted with the help of diagrammatic Lattice Perturbation Theory (LPT). Such calculations are typically restricted to 1-loop order, but one may overcome this limitation and calculate hypercubic corrections for any operator and action beyond the 1-loop order using Numerical Stochastic Perturbation Theory (NSPT). In this study, we explore the practicability of such an approach and consider, as a first test, the case of Wilson fermion bilinear operators in a quenched theory. Our results allow us to compare boosted and unboosted perturbative corrections up to the 3-loop order.Comment: 7 pages, 6 figures, talk presented at the 32nd International Symposium on Lattice Field Theory (Lattice 2014), 23-28 June 2014, New York, USA; PoS(LATTICE2014)29

Discretization Errors for the Gluon and Ghost Propagators in Landau Gauge using NSPT

The subtraction of hypercubic lattice corrections, calculated at 1-loop order in lattice perturbation theory (LPT), is common practice, e.g., for determinations of renormalization constants in lattice hadron physics. Providing such corrections beyond 1-loop order is however very demanding in LPT, and numerical stochastic perturbation theory (NSPT) might be the better candidate for this. Here we report on a first feasibility check of this method and provide (in a parametrization valid for arbitrary lattice couplings) the lattice corrections up to 3-loop order for the SU(3) gluon and ghost propagators in Landau gauge. These propagators are ideal candidates for such a check, as they are available from lattice simulations to high precision and can be combined to a renormalization group invariant product (Minimal MOM coupling) for which a 1-loop LPT correction was found to be insufficient to remove the bulk of the hypercubic lattice artifacts from the data. As a bonus, we also compare our results with the ever popular H(4) method.Comment: 7 pages, 5 figures, presented at the 31st International Symposium on Lattice Field Theory (Lattice 2013), 29 July - 3 August 2013, Mainz, German

Algorithmic Advancements and Massive Parallelism for Large-Scale Datasets in Phylogenetic Bayesian Markov Chain Monte Carlo

Datasets used for the inference of the "tree of life" grow at unprecedented rates, thus inducing a high computational burden for analytic methods. First, we introduce a scalable software package that allows us to conduct state of the art Bayesian analyses on datasets of almost arbitrary size. Second, we derive a proposal mechanism for MCMC that is substantially more efficient than traditional branch length proposals. Third, we present an efficient algorithm for solving the rogue taxon problem

Size-Dependent Variability in Flow and Viscoelastic Behavior of Levan Produced by Gluconobacter albidus TMW 2.1191

Levan is a fructan-type exopolysaccharide which is produced by many microbes from sucrose via extracellular levansucrases. The hydrocolloid properties of levan depend on its molecular weight, while it is unknown why and to what extent levan is functionally diverse depending on ist size. The aim of our study was to gain deeper insight into the size-dependent functional variability of levan. For this purpose, levans of different sizes were produced using the water kefir isolate Gluconobacter albidus TMW 2.1191 and subsequently rheologically characterized. Three levan types could be identified, which are similarly branched, but differ significantly in their molecular size and rheological properties. The smallest levan (10$^{8}$ Da) produced at pH ≥ 4.5 were shear-thinning, and the levan produced at pH 5.0 showed a gel-like behavior at 5% (w/v). A third (intermediate) levan variant was obtained through production in buffers at pH 4.0 and exhibited the properties of a viscoelastic fluid up to concentrations of 15% (w/v). Our study reveals that the rheological properties of levan are determined by its size and polydispersity, rather than by the amount of levan used or the structural composition

Light-cone distribution amplitudes of the baryon octet

We present results of the first ab initio lattice QCD calculation of the normalization constants and first moments of the leading twist distribution amplitudes of the full baryon octet, corresponding to the small transverse distance limit of the associated S-wave light-cone wave functions. The P-wave (higher twist) normalization constants are evaluated as well. The calculation is done using $N_f=2+1$ flavors of dynamical (clover) fermions on lattices of different volumes and pion masses down to 222 MeV. Significant SU(3) flavor symmetry violation effects in the shape of the distribution amplitudes are observed.Comment: Update to the version published in JHE

Energy Drinks and Their Acute Effects on Arterial Stiffness in Healthy Children and Teenagers: A Randomized Trial

Adolescents are the main consumer group of energy drinks (ED). Studies suggest that acute ED consumption is associated with increased peripheral blood pressure. Little is known of the ED-induced effects on arterial stiffness. Therefore, this study aimed to investigate the acute effects of ED consumption on arterial stiffness in healthy children and teenagers by conducting a prospective, randomized, single-blind, placebo-controlled, crossover clinical trial. Study participants (n = 27, mean age = 14.53 years) consumed a body-weight-adjusted amount of an ED or a placebo on two consecutive days. Arterial stiffness was evaluated sonographically by two-dimensional speckle tracking of the common carotid artery (CCA) at baseline and up to four hours after beverage consumption. The ED intake led to a significantly decreased peak circumferential strain of the CCA (11.78 +/- 2.70% vs. 12.29 +/- 2.68%, p = 0.043) compared with the placebo. The results of this study indicate that the acute ED consumption might be associated with increased arterial stiffness in healthy children and teenagers. Minors, particularly those with increased cardiovascular morbidity, should be discouraged from ED consumption

Discursos y autorrepresentaciones de magistrados federales en los casos de corrupción y delitos económicos en Brasil

El artículo analisa los discursos y las autorrepresentaciones de magistrados federales en los casos de corrupción y de delitos económicos en Brasil. El texto utiliza los datos de la investigación financiada por la ESMPU (Escuela Superior del Ministerio Público de la Unión) sobre la persecución penal de la corrupción y de los delitos económicos en el sistema de justicia federal. El estudio aplicó técnicas quantitativas y cualitativas. Se inició con el análisis estadístico del flujo del sistema de justicia criminal. A partir del detallamento nacional de las acciones penales y sobreseimientos, en la segunda fase de la investigación (cualitativa), las entrevistas en profundidad y los grupos focales posibilitaron comprender las práticas, los conflictos y los arreglos organizacionales y, asimismo, las distintas visiones de los actores involucrados en la persecución penal. En este artículo, utilzamos los datos de la fase cualitativa para analisar las distintas visiones de los magistrados federales sobre el objeto de la investigación