We propose and analyze a mechanism for rectification of spin transport through a small junction between two spin baths or leads. For interacting baths, we show that transport is conditioned on the ...spacial asymmetry of the quantum junction mediating the transport, and attribute this behavior to a gapped spectral structure of the lead-system-lead configuration. For noninteracting leads, a minimal quantum model that allows for spin rectification requires an interface of only two interacting two-level systems. In our paper, we have performed a thorough study of the current, including its time dependence and steady-state value. We obtain approximate results with a weak-coupling Born master equation in excellent agreement with matrix-product-state calculations that are extrapolated in time by mimicking absorbing boundary conditions. These results should be observable in controlled spin systems realized with cold atoms, trapped ions, or in electrons in quantum dot arrays.
El presente documento tiene por objetivo describir el panorama general de la adopción de las normas internacionales de información financiera en Colombia ad portas de su implementación. La ...metodología empleada es la investigación documental. Durante el recorrido del artículo, se revisa la normatividad colombiana en materia contable, la evolución de las normas internacionales de información financiera, las normas internacionales de información financiera para Pymes, hasta llegar al periodo de convergencia.
We derive the dynamical equation of the reduced propagator, an object that evolves state vectors of the system conditioned to the dynamics of its environment, which is not necessarily in the vacuum ...state at the initial time. Such a reduced propagator is essential to obtain multiple-time correlation functions (MTCFs). We also study the evolution of MTCFs within the weak-coupling limit and show that the quantum regression theorem is, in general, not satisfied. We illustrate the theory in two different cases: first, solving an exact model, and, second, presenting the results of the numerical integration for a system coupled with a thermal environment through a nondiagonal interaction.
Methicillin-resistant Staphylococcus aureus (MRSA) is a human pathogen of great concern owing to its antimicrobial resistance and virulence properties. Here we report the first draft genome sequence ...of a mecA-negative community-associated MRSA strain isolated from a healthy young Mexican paediatric carrier in order to reveal the genomic structure underlying the multidrug-resistant phenotype and to discover the virulence properties of this strain.
The draft genome sequence of S. aureus L401 was obtained using an Ion Torrent™ PGM platform. De novo assembled contigs were annotated, and antimicrobial resistance genes and virulence factors were identified using ResFinder and VirulenceFinder, respectively. In addition, a mutational survey of native pbp, gdpP and yjbH genes was performed. In silico multilocus sequence typing (MLST) and spa typing were also performed.
S. aureus L401 has a genome size of 2 831 587 bp with 2799 protein-coding sequences. Various antimicrobial resistance genes conferring resistance to aminoglycosides, β-lactams, fluoroquinolones and macrolide–lincosamide–streptogramin B antimicrobials were found. Although both mecA and staphylococcal cassette chromosome mec (SCCmec) elements were absent, a missense mutation in PBP3 was identified. Moreover, genes encoding exfoliative toxin A, γ- and β-haemolysin, and several enterotoxins were also identified. S. aureus L401 belongs to ST109 and spa type t209.
The availability of this genome will allow an insight into S. aureus resistance and virulence determinants as well as its epidemiology, lineage, evolution and genomic features involved in the paediatric commensal carriage.
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