Molar mass and solution conformation of branched alpha(1 - 4), alpha(1 - 6) Glucans. Part I: Glycogens in water

Solution molar masses and conformations of glycogens from different sources (rabbit, oyster, mussel and bovine) were analysed using sedimentation velocity in the analytical ultracentrifuge, size-exclusion chromatography coupled to multi-angle laser light scattering (SEC-MALLS), size-exclusion chromatography coupled to a differential pressure viscometer and dynamic light scattering. Rabbit, oyster and mussel glycogens consisted of one population of high molar mass (weight averages ranging from 4.6 x 106 to 1.1 x 107 g/mol) as demonstrated by sedimentation velocity and SEC-MALLS, whereas bovine glycogen had a bimodal distribution of significantly lower molar mass (1.0 x 105 and 4.5 x 105 g/mol). The spherical structure of all glycogen molecules was demonstrated in the slopes of the Mark-Houwink-Kuhn-Sakurada-type power-law relations for sedimentation coefficient (s20,wo), intrinsic viscosity ([η]), radius of gyration (rg,z) and radius of hydration (rH,z), respectively, and was further supported by the � (=rg,z/rH,z) function, the fractal dimension and the Perrin function. The degree of branching was estimated to be ∼10% from the shrinking factors, g′ (=[η]branched/[η]linear) and also h (=(f/fo)branched/(f/fo)linear), respectively, where (f/fo) is the translational frictional ratio, consistent with expectation. © 2007 Elsevier Ltd. All rights reserved

Transverse momentum distributions inside the nucleon from lattice QCD

We study transverse momentum dependent parton distribution functions (TMDs) with non-local operators in lattice QCD, using MILC/LHPC lattices. Results obtained with a simplified operator geometry show visible dipole deformations of spin-dependent quark momentum densities.United States. Dept. of Energy (grant DE-FG02-94ER40818

Transverse momentum dependent quark densities from Lattice QCD

We study transverse momentum dependent parton distribution functions (TMDs) with non‐local operators in lattice QCD, using MILC∕LHPC lattices. We discuss the basic concepts of the method, including renormalization of the gauge link. Results obtained with a simplified operator geometry show visible dipole deformations of spin‐dependent quark momentum densities.United States. Dept. of Energy (grant DEFG02- 94ER40818

How to Optimally Constrain Galaxy Assembly Bias: Supplement Projected Correlation Functions with Count-in-cells Statistics

Most models for the connection between galaxies and their haloes ignore the possibility that galaxy properties may be correlated with halo properties other than mass, a phenomenon known as galaxy assembly bias. Yet, it is known that such correlations can lead to systematic errors in the interpretation of survey data. At present, the degree to which galaxy assembly bias may be present in the real Universe, and the best strategies for constraining it remain uncertain. We study the ability of several observables to constrain galaxy assembly bias from redshift survey data using the decorated halo occupation distribution (dHOD), an empirical model of the galaxy--halo connection that incorporates assembly bias. We cover an expansive set of observables, including the projected two-point correlation function $w_{\mathrm{p}}(r_{\mathrm{p}})$, the galaxy--galaxy lensing signal $\Delta \Sigma(r_{\mathrm{p}})$, the void probability function $\mathrm{VPF}(r)$, the distributions of counts-in-cylinders $P(N_{\mathrm{CIC}})$, and counts-in-annuli $P(N_{\mathrm{CIA}})$, and the distribution of the ratio of counts in cylinders of different sizes $P(N_2/N_5)$. We find that despite the frequent use of the combination $w_{\mathrm{p}}(r_{\mathrm{p}})+\Delta \Sigma(r_{\mathrm{p}})$ in interpreting galaxy data, the count statistics, $P(N_{\mathrm{CIC}})$ and $P(N_{\mathrm{CIA}})$, are generally more efficient in constraining galaxy assembly bias when combined with $w_{\mathrm{p}}(r_{\mathrm{p}})$. Constraints based upon $w_{\mathrm{p}}(r_{\mathrm{p}})$ and $\Delta \Sigma(r_{\mathrm{p}})$ share common degeneracy directions in the parameter space, while combinations of $w_{\mathrm{p}}(r_{\mathrm{p}})$ with the count statistics are more complementary. Therefore, we strongly suggest that count statistics should be used to complement the canonical observables in future studies of the galaxy--halo connection.Comment: Figures 3 and 4 show the main results. Published in Monthly Notices of the Royal Astronomical Societ

EFFECTS OF SHADOWING IN DOUBLE POMERON EXCHANGE PROCESSES

The effects of shadowing in double Pomeron exchange processes are investigated within an eikonal approach with a Gaussian input. Damping factors due to screening are calculated for this process and compared with the factors obtained for total, elastic and single diffraction cross sections. Our main conclusion is that counting rate calculations, of various double Pomeron exchange processes (without screening corrections) such as heavy quark and Higgs production are reduced by a factor of 5 in the LHC energy range, when screening corrections are applied.Comment: 9 pages, latex, 5 figures obtainable from author

Time-frequency characterization of femtosecond extreme ultraviolet pulses

A measurement of chirp and pulse duration of fifth harmonic of a frequency-doubled Ti:sapphire laser was presented. The photoelectron signal due to cross correlation of harmonics generated by 400 nm blue light and an 800 nm infrared probe pulse, was measured using energy resolved cross-correlation method. Results demonstrated that the technique could be used to characterize the time-frequency behavior of much higher-order harmonics

YourMOOC4all: a recommender system for MOOCs based on collaborative filtering implementing UDL

YourMOOC4all is a pilot research project to collect feedback requests regarding accessible design for Massive Open Online Courses (MOOCs). In this online application, a specific website offers the possibility for any learner to freely judge if a particular MOOC complies Universal Design for Learning (UDL) principles. User feedback is of great value for the future development of MOOC platforms and MOOC educational resources, as it will help to follow De-sign for All guidelines. YourMOOC4all is a recommender system which gathers valuable information directly from learners to improve aspects such as the quality, accessibility and usability of this online learning environment. The final objective of collecting user’s feedback is to advice MOOC providers about the missing means for meeting learner needs. This paper describes the pedagogical and technological background of YourMOOC4all and its use cases

Cancer gene prioritization by integrative analysis of mRNA expression and DNA copy number data: a comparative review

A variety of genome-wide profiling techniques are available to probe complementary aspects of genome structure and function. Integrative analysis of heterogeneous data sources can reveal higher-level interactions that cannot be detected based on individual observations. A standard integration task in cancer studies is to identify altered genomic regions that induce changes in the expression of the associated genes based on joint analysis of genome-wide gene expression and copy number profiling measurements. In this review, we provide a comparison among various modeling procedures for integrating genome-wide profiling data of gene copy number and transcriptional alterations and highlight common approaches to genomic data integration. A transparent benchmarking procedure is introduced to quantitatively compare the cancer gene prioritization performance of the alternative methods. The benchmarking algorithms and data sets are available at http://intcomp.r-forge.r-project.orgComment: PDF file including supplementary material. 9 pages. Preprin