Link Invariants for Flows in Higher Dimensions

Linking numbers in higher dimensions and their generalization including gauge fields are studied in the context of BF theories. The linking numbers associated to $n$-manifolds with smooth flows generated by divergence-free p-vector fields, endowed with an invariant flow measure are computed in different cases. They constitute invariants of smooth dynamical systems (for non-singular flows) and generalizes previous results for the 3-dimensional case. In particular, they generalizes to higher dimensions the Arnold's asymptotic Hopf invariant for the three-dimensional case. This invariant is generalized by a twisting with a non-abelian gauge connection. The computation of the asymptotic Jones-Witten invariants for flows is naturally extended to dimension n=2p+1. Finally we give a possible interpretation and implementation of these issues in the context of string theory.Comment: 21+1 pages, LaTeX, no figure

Catalogação de obras raras: análise das perspectivas bibliográfica e bibliológica

A catalogação é uma atividade corriqueira no trabalho do bibliotecário. Alguns recursos informacionais necessitam de uma descrição bibliográfica mais exaustiva e completa para possibilitar a recuperação dos mesmos pelos usuários por meio do catálogo. Destacam-se nesse contexto as obras raras, que possuem características distintas dos livros modernos. Diante disso buscou-se compreender como ocorre o processo de catalogação de obras raras, no contexto das bibliotecas, e quais os instrumentos e metodologias são utilizados a partir da análise dos aspectos bibliográfico e bibliológico.

Antibiotic resistance and the one health approach. The importance of teaching OMICS at Universities

PM003/2016).In the past, much like today, the field of antibacterial drugs revolved around compounds featuring a crucial four-atom amide ring known as a β-lactam. (...)publishersversionpublishe

Interaction of [(VO)-O-IV(acac)(2)] with Human Serum Transferrin and Albumin

VO(acac)(2)] is a remarkable vanadium compound and has potential as a therapeutic drug. It is important to clarify how it is transported in blood, but the reports addressing its binding to serum proteins have been contradictory. We use several spectroscopic and mass spectrometric techniques (ESI and MALDI-TOF), small-angle X-ray scattering and size exclusion chromatography (SEC) to characterize solutions containing [VO(acac)(2)] and either human serum apotransferrin (apoHTF) or albumin (HSA). DFT and modeling protein calculations are carried out to disclose the type of binding to apoHTF. The measured circular dichroism spectra, SEC and MALDI-TOF data clearly prove that at least two VOacac moieties may bind to apoHTF, most probably forming [(VO)-O-IV(acac)(apoHTF)] complexes with residues of the HTF binding sites. No indication of binding of [VO(acac)(2)] to HSA is obtained. We conclude that (VO)-O-IV-acac species may be transported in blood by transferrin. At very low complex concentrations speciation calculations suggest that [(VO)(apoHTF)] species form.Fundacao para a Ciencia e Tecnologia (FCT), Portugal [ RECI/QEQMED/0330/2012, PTDC/QEQ-MED/1902/2014]FCT [IF/00100/2013, IF/00007/2015]PROTEOMASS Scientific SocietyUCIBIO, Unidade de Ciencias Biomoleculares Aplicadas [UID/Multi/04378/2013]ERDF [POCI-01-0145-FEDER-007728, POCI-01-0145-FEDER-007265]info:eu-repo/semantics/publishedVersio

MIGHTEE: total intensity radio continuum imaging and the COSMOS / XMM-LSS Early Science fields

© 2021 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society. This is the accepted manuscript version of an article which has been published in final form at https://doi.org/10.1093/mnras/stab3021MIGHTEE is a galaxy evolution survey using simultaneous radio continuum, spectro-polarimetry, and spectral line observations from the South African MeerKAT telescope. When complete, the survey will image $\sim$20 deg$^{2}$ over the COSMOS, E-CDFS, ELAIS-S1, and XMM-LSS extragalactic deep fields with a central frequency of 1284 MHz. These were selected based on the extensive multiwavelength datasets from numerous existing and forthcoming observational campaigns. Here we describe and validate the data processing strategy for the total intensity continuum aspect of MIGHTEE, using a single deep pointing in COSMOS (1.6 deg$^{2}$) and a three-pointing mosaic in XMM-LSS (3.5 deg$^{2}$). The processing includes the correction of direction-dependent effects, and results in thermal noise levels below 2~$\mathrm{\mu}$Jy beam$^{-1}$ in both fields, limited in the central regions by classical confusion at $\sim$8$''$ angular resolution, and meeting the survey specifications. We also produce images at $\sim$5$''$ resolution that are $\sim$3 times shallower. The resulting image products form the basis of the Early Science continuum data release for MIGHTEE. From these images we extract catalogues containing 9,896 and 20,274 radio components in COSMOS and XMM-LSS respectively. We also process a close-packed mosaic of 14 additional pointings in COSMOS and use these in conjunction with the Early Science pointing to investigate methods for primary beam correction of broadband radio images, an analysis that is of relevance to all full-band MeerKAT continuum observations, and wide field interferometric imaging in general. A public release of the MIGHTEE Early Science continuum data products accompanies this article.Peer reviewedFinal Accepted Versio

Molecular excitation in the Interstellar Medium: recent advances in collisional, radiative and chemical processes

We review the different excitation processes in the interstellar mediumComment: Accepted in Chem. Re