Normality in group rings

Let $KG$ be the group ring of a group $G$ over a commutative ring $K$ with unity. The rings $KG$ are described for which $xx^\sigma=x^\sigma x$ for all $x=\sum_{g\in G}\alpha_gg\in KG$, where \quad $x\mapsto x^\sigma=~\sum_{g\in G}\alpha_gf(g)\sigma(g)$\quad is an involution of $KG$; here $f: G\to U(K)$ is a homomorphism and $\sigma$ is an anti-automorphism of order two of $G$.Comment: 8 page

On filtered multiplicative bases of some associative algebras

We deal with the existing problem of filtered multiplicative bases of finite-dimensional associative algebras. For an associative algebra A over a field, we investigate when the property of having a filtered multiplicative basis is hereditated by homomorphic images or by the associated graded algebra of $A$. These results are then applied to some classes of group algebras and restricted enveloping algebras.Comment: 10 page

On the manipulability of dual cooperative robots

The definition of manipulability ellipsoids for dual robot systems is given. A suitable kineto-static formulation for dual cooperative robots is adopted which allows for a global task space description of external and internal forces, and relative velocities. The well known concepts of force and velocity manipulability ellipsoids for a single robot are formally extended and the contributions of the two single robots to the cooperative system ellipsoids are illustrated. Duality properties are discussed. A practical case study is developed

Impact of Internet gambling on problem gambling among adolescents in Italy: Findings from a large-scale nationally representative survey

Aims: The primary aim of the present study was to understand the impact of online gambling on gambling problems in a large-scale nationally representative sample of Italian youth, and to identify and then further examine a subgroup of online gamblers who reported higher rates of gambling problems. Design: Data from the ESPAD®Italia2013 (European School Survey Project on Alcohol and Other Drugs) Study were used for analyses of adolescent Internet gambling. Setting: Self-administered questionnaires were completed by a representative sample of high school students, aged 15–19 years. Participants: A total of 14,778 adolescent students. Measurements: Respondents’ problem gambling severity; gambling behavior (participation in eight different gambling activities, the number of gambling occasions and the number of online gambling occasions, monthly gambling expenditure); Socio-demographics (e.g., family structure and financial status); and control variables were measured individually (i.e., use of the Internet for leisure activities and playing video games). Findings: Rates of problem gambling were five times higher among online gamblers than non-online gamblers. In addition, factors that increased the risk of becoming a problem online gambler included living with non-birth parents, having a higher perception of financial family status, being more involved with gambling, and the medium preferences of remote gamblers (e.g., Internet cafes, digital television, and video game console). Conclusions: The online gambling environment may pose significantly greater risk to vulnerable players. Family characteristics and contextual elements concerning youth Internet gambling (e.g., remote mediums) may play a key role in explaining problem online gambling among adolescents

On the subalgebra lattice of a Leibniz algebra

In this paper, we begin to study the subalgebra lattice of a Leibniz algebra. In particular, we deal with Leibniz algebras whose subalgebra lattice is modular, upper semi-modular, lower semi-modular, distributive, or dually atomistic. The fact that a non-Lie Leibniz algebra has fewer one-dimensional subalgebras in general results in a number of lattice conditions being weaker than in the Lie case

Do metal mixture insults to the soil invisible majority reduce ecosystem service quality?

Non-Peer Reviewe

On fractional Choquard equations

We investigate a class of nonlinear Schrodinger equations with a generalized Choquard nonlinearity and fractional diffusion. We obtain regularity, existence, nonexistence, symmetry as well as decays properties.Comment: revised version, 22 page

Nitrogen cycling in root associated soils at bolting, flowering and seed pod filling across eight diverse Brassica napus (canola) genotypes

Non-Peer ReviewedNitrogen (N) mineralization and nitrification can be used predict the amount of N that is available to crops. Brassica napus L. (canola) production is N intensive; therefore, to improve and sustain yields, a better understanding of N cycling patterns for fertilization application is needed. The objective of this study is to examine N cycling after urea fertilization at the three major canola growth stages: bolting, flowering and seed pod filling; and how N cycling may differ between diverse canola lines grown in different soil types. Eight diverse B. napus lines were grown on Dark Brown Chernozemic soil and Black Chernozemic soil in Saskatchewan, Canada. Root-associated soils were collected from each line at bolting, flowering and seed pod filling, and this soil was analyzed for potential nitrification and mineralization, as well as soil nitrate and ammonium content. We predict that potential nitrification will be higher during the bolting and flowering stages of canola growth because the urea fertilizer that was applied to the field would have been converted to nitrate-N, which is plant available. We predict that potential mineralization will be higher during flowering and seed pod filling, because the demand for N to make protein-rich seeds is high enough to deplete much of the inorganic fertilizer N. We also predict that both nitrate-N and ammonium-N will decrease over the growing season, with significant differences between the canola lines and the soil environments. Mixed effect analyses and ANOVA will be used to analyze N cycling in the soil in relation to soil type differences, canola line differences, and growth stage differences. By characterizing soil N processes, this research will advance efforts to understand and improve N uptake for B. napus lines