656 research outputs found
Explicit determination of a 727-dimensional root space of the hyperbolic Lie algebra
The 727-dimensional root space associated with the level-2 root \bLambda_1
of the hyperbolic Kac--Moody algebra is determined using a recently
developed string theoretic approach to hyperbolic algebras. The explicit form
of the basis reveals a complicated structure with transversal as well as
longitudinal string states present.Comment: 12 pages, LaTeX 2
On the fundamental representation of Borcherds algebras with one imaginary simple root
Borcherds algebras represent a new class of Lie algebras which have almost
all the properties that ordinary Kac-Moody algebras have, and the only major
difference is that these generalized Kac-Moody algebras are allowed to have
imaginary simple roots. The simplest nontrivial examples one can think of are
those where one adds ``by hand'' one imaginary simple root to an ordinary
Kac-Moody algebra. We study the fundamental representation of this class of
examples and prove that an irreducible module is given by the full tensor
algebra over some integrable highest weight module of the underlying Kac-Moody
algebra. We also comment on possible realizations of these Lie algebras in
physics as symmetry algebras in quantum field theory.Comment: 8 page
BPS Saturation from Null Reduction
We show that any -dimensional strictly stationary, asymptotically
Minkowskian solution of a null reduction of -dimensional pure
gravity must saturate the BPS bound provided that the KK vector field can be
identified appropriately. We also argue that it is consistent with the field
equations.Comment: 10 page
Miravirsen (SPC3649) can inhibit the biogenesis of miR-122
MicroRNAs (miRNAs) are short noncoding RNAs, which bind to messenger RNAs and regulate protein expression. The biosynthesis of miRNAs includes two precursors, a primary miRNA transcript (pri-miRNA) and a shorter pre-miRNA, both of which carry a common stem-loop bearing the mature miRNA. MiR-122 is a liver-specific miRNA with an important role in the life cycle of hepatitis C virus (HCV). It is the target of miravirsen (SPC3649), an antimiR drug candidate currently in clinical testing for treatment of HCV infections. Miravirsen is composed of locked nucleic acid (LNAs) ribonucleotides interspaced throughout a DNA phosphorothioate sequence complementary to mature miR-122. The LNA modifications endow the drug with high affinity for its target and provide resistance to nuclease degradation. While miravirsen is thought to work mainly by hybridizing to mature miR-122 and blocking its interaction with HCV RNA, its target sequence is also present in pri- and pre-miR-122. Using new in vitro and cellular assays specifically developed to discover ligands that suppress biogenesis of miR-122, we show that miravirsen binds to the stem-loop structure of pri- and pre-miR-122 with nanomolar affinity, and inhibits both Dicer- and Drosha-mediated processing of miR-122 precursors. This inhibition may contribute to the pharmacological activity of the drug in ma
AcĂşmulo de nitrogĂŞnio e fĂłsforo no tecido de plantas anuais de inverno manejadas sob sistema plantio direto e sistema de cultivo convencional
O sistema de manejo pode afetar a disponibilidade de nutrientes para as plantas, em decorrĂŞncia do sistema de rotação de culturas e da quantidade de resĂduo vegetal presente na superfĂcie do solo. O objetivo deste trabalho foi avaliar a quantidade de nitrogĂŞnio (N) e fĂłsforo (P) acumulados no tecido vegetal de aveia preta, trigo, centeio, ervilhaca, nabo e tremoço azul, alĂ©m de verificar seu estado nutricional de N e P. O experimento esta instalado no Instituto AgronĂ´mico do Paraná (IAPAR) em Pato Branco, Paraná, em um Latossolo Vermelho aluminofĂ©rrico. Em maio de 2011 os tratamentos foram semeados, sendo seis plantas de cobertura: trigo, aveia preta, centeio, ervilhaca, nabo forrageiro e tremoço azul cultivados sob Sistema Plantio Direto (SPD) e Sistema de Cultivo Convencional (SCC). Em setembro de 2011efetuou-se a coleta do material verde da parte aĂ©rea, o qual foi seco a 65ÂşC e posteriormente digerido com uma mistura de H2SO4 e H2O2, onde foram determinados os teores de nitrogĂŞnio total (Ntotal) e fĂłsforo total (Ptotal), tambĂ©m foi quantificado o teor de carbono das amostras, e por fim calculou-se o Ăndice de nutrição de fĂłsforo (P Ăndex) e de nitrogĂŞnio (N Ăndex). Realizou-se a comparação das mĂ©dias das plantas anuais de inverno e dos sistemas de manejo de solo por meio do teste de SCOTT-KNOTT. O sistema de cultivo influencia no acĂşmulo de N e P, consequentemente no Ăndice de nutrição dos mesmos, sendo maior no SPD. A ervilhaca e centeio possuem grande capacidade de reciclar P
Top Management Team Diversity: A systematic Review
Empirical research investigating the impact of top management team (TMT)
diversity on executives’ decision making has produced inconclusive results.
To synthesize and aggregate the results on the diversity-performance
link, a meta-regression analysis (MRA) is conducted. It integrates more
than 200 estimates from 53 empirical studies investigating TMT diversity
and its impact on the quality of executives’ decision making as reflected
in corporate performance. The analysis contributes to the literature by
theoretically discussing and empirically examining the effects of TMT diversity
on corporate performance. Our results do not show a link between TMT
diversity and performance but provide evidence for publication bias. Thus,
the findings raise doubts on the impact of TMT diversity on performance
Partially quenched chiral perturbation theory and numerical simulations
The dependence of the pseudoscalar meson mass and decay constant is compared
to one-loop Partially Quenched Chiral Perturbation Theory (PQChPT) in a
numerical simulation with two light dynamical quarks. The characteristic
behaviour with chiral logarithms is observed. The values of the fitted
PQChPT-parameters are in a range close to the expectation in continuum in spite
of the fact that the lattice spacing is still large, namely a=0.28 fm.Comment: 11 pages, 3 figures; discussion of the results in section 3 extende
Realizability of Polytopes as a Low Rank Matrix Completion Problem
This article gives necessary and sufficient conditions for a relation to be
the containment relation between the facets and vertices of a polytope. Also
given here, are a set of matrices parameterizing the linear moduli space and
another set parameterizing the projective moduli space of a combinatorial
polytope
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