Rio de Janeiro State University

About: Rio de Janeiro State University is a education organization based out in Rio de Janeiro, Brazil. It is known for research contribution in the topics: Population & Large Hadron Collider. The organization has 16631 authors who have published 30919 publications receiving 465753 citations. The organization is also known as: UERJ & Rio de Janeiro State University.

Suppression and azimuthal anisotropy of prompt and nonprompt J/ψ production in PbPb collisions at √sNN = 2.76 TeV

Abstract: The nuclear modification factor [Formula: see text] and the azimuthal anisotropy coefficient [Formula: see text] of prompt and nonprompt (i.e. those from decays of b hadrons) [Formula: see text] mesons, measured from PbPb and pp collisions at [Formula: see text] [Formula: see text] at the LHC, are reported. The results are presented in several event centrality intervals and several kinematic regions, for transverse momenta [Formula: see text] [Formula: see text] and rapidity [Formula: see text], extending down to [Formula: see text] [Formula: see text] in the [Formula: see text] range. The [Formula: see text] of prompt [Formula: see text] is found to be nonzero, but with no strong dependence on centrality, rapidity, or [Formula: see text] over the full kinematic range studied. The measured [Formula: see text] of nonprompt [Formula: see text] is consistent with zero. The [Formula: see text] of prompt [Formula: see text] exhibits a suppression that increases from peripheral to central collisions but does not vary strongly as a function of either y or [Formula: see text] in the fiducial range. The nonprompt [Formula: see text] [Formula: see text] shows a suppression which becomes stronger as rapidity or [Formula: see text] increases. The [Formula: see text] and [Formula: see text] of open and hidden charm, and of open charm and beauty, are compared.

On the limits of highest-occupied molecular orbital driven reactions: the frontier effective-for-reaction molecular orbital concept.

Abstract: We carried out Hartree−Fock (HF) and density functional theory calculations for 61 compounds, the conjugated bases of carboxylic acids, phenols, and alcohols, and analyzed their acid−base behavior using molecular orbital (MO) energies and their dependence on solvent effects. Despite the well-known correlation between highest-occupied MO (HOMO) energies and pKa, we observed that HOMO energies are inadequate to describe the acid−base behavior of these compounds. Therefore, we established a criterion to identify the best frontier MO for describing pKa values and also to understand why the HOMO approach fails. The MO that fits our criterion provided very good correlations with pKa values, much better than those obtained by HOMO energies. Since they are the frontier molecular orbitals that drive the acid−base reactions in each compound, they were called frontier effective-for-reaction MOs, or FERMOs. By use of the FERMO concept, the reactions that are HOMO driven, and those that are not, can be better explaine...

Domestic dogs in protected areas: a threat to Brazilian mammals?

Abstract: The presence of domestic dogs (Canis lupus familiaris) in Brazilian protected areas is fairly frequent. The interaction of such dogs with native animals leads to population declines for many species, particularly carnivores. In this paper the main threats dogs bring about Brazilian biodiversity are assessed with a focus on protected areas. We collected information from papers on the interaction of dogs and wildlife species as well as from interviews with National Park managers. Studies in protected areas in Brazil listed 37 native species affected by the presence of dogs due to competition, predation, or pathogen transmission. Among the 69 threatened species of the Brazilian fauna, 55% have been cited in studies on dogs. Dog occurrence was assessed for 31 National Parks in Brazil. The presence of human residents and hunters in protected areas were the factors most often quoted as facilitating dog occurrence. These may be feral, street or domestically owned dogs found in protected areas in urban, rural or natural areas. Effective actions to control this invasive alien species in natural areas must consider dog dependence upon humans, pathways of entry, and the surrounding landscape and context.