Maxwell consideration of polaritonic quasi-particle Hamiltonians in multi-level systems

We address the problem of the correct description of light-matter coupling for excitons and cavity photons in the case of systems with multiple photon modes or excitons, respectively. In the literature, two different approaches for the phenomenological coupling Hamiltonian can be found: Either one single Hamiltonian with a basis whose dimension equals the sum of photonic modes and excitonic resonances is used. Or a set of independent Hamiltonians, one for each photon mode, is chosen. Both are usually used equivalently for the same kind of multi-photonic systems which cannot be correct. However, identifying the suitable Hamiltonian is difficult when modeling experimental data. By means of numerical transfer matrix calculations, we demonstrate the scope of application of each approach: The first one holds only for the coupling of a single photon state to several excitons, while in the case of multiple photon modes, separate Hamiltonians must be used for each photon mode

Temperature dependent second-order Raman scattering in CuI

We report second-order Raman scattering spectra of copper iodide bulk single crystals aside from the fundamental TO and LO mode. The spectral shape was reproduced by a 2-phonon density of states calculated by DFT. Characteristic multi-phonon features were identified and assigned to combination, overtone and difference modes. In this way, the energy of acoustic zone-boundary phonons was determined. The temperature dependence of those modes and the fundamental optical phonons was analyzed by means of phonon-phonon interactions and lattice expansion effects up to room temperature. Processes related to the mode energy shift and width were identified for phonons at high symmetry points. The shifts due to lattice expansion are in accordance with the predictions by DFT in quasi-harmonic approximation using PBEsol functional.Comment: 11 pages, 6 figures, 3 tables. Submitted to Phys. Rev.

Actinobaculum schaalii, a Common Uropathogen in Elderly Patients, Denmark

This organism is identified more often by PCR than by cultivation

Inter-rater reliability of the extended Composite Quality Score (CQS-2)

AimTo establish the inter-rater reliability of the Composite Quality Score (CQS-2) and to test the null hypothesis that it did not differ significantly from that of the first CQS version (CQS-1).Materials and methodsFour independent raters were selected to rate 45 clinical trial reports using CQS-1 and CQS-2. The raters remained unaware of each other’s participation in this study until all rating had been completed. Each rater received only one rating template at a time in a random sequence for CQS-1 and CQS-2 rating. Raters completed each template and sent these back to the principal investigator. Each rater received their next template 2 weeks after submission of the completed previous template. The inter-rater reliabilities for the overall appraisal score of the CQS-1 and the CQS-2 were established by using the Brennan-Prediger coefficient (BPC). The coefficients of both CQS versions were compared by using the two-sample z-test. During secondary analysis, the BPCs for every criterion and each corroboration level for both CQS versions were established.ResultsThe BPC for the CQS-1 was 0.85 (95% CI: 0.64–1.00) and for the CQS-2 it was 1.00 (95% CI: 0.94–1.00), suggesting a very high inter-rater reliability for both. The difference between the two CQS versions was statistically not significant (p = 0.17). The null hypothesis was accepted.ConclusionThe CQS-2 is still under development, This study shows that it is associated with a very high inter-rater reliability, which did not statistically significantly differ from that of the CQS-1. The promising results of this study warrant further investigation in the applicability of the CQS-2 as an appraisal tool for prospective controlled clinical therapy trials

Investigation of the deposition and emission of mercury in arctic snow during an atmospheric mercury depletion event

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/94701/1/jgrd14741.pd

Demystifying the coronal line region of active galactic nuclei: spatially resolved spectroscopy with HST

We present an analysis of STIS/HST optical spectra of a sample of ten Seyfert galaxies aimed at studying the structure and physical properties of the coronal-line region (CLR). The high-spatial resolution provided by STIS allowed us to resolve the CLR and obtain key information about the kinematics of the coronal-line gas, measure directly its spatial scale, and study the mechanisms that drive the high-ionisation lines. We find CLRs extending from just a few parsecs (~10 pc) up to 230 pc in radius, consistent with the bulk of the coronal lines (CLs) originating between the BLR and NLR, and extending into the NLR in the case of [FeVII] and [NeV] lines. The CL profiles strongly vary with the distance to the nucleus. We observed line splitting in the core of some of the galaxies. Line peak shifts, both red- and blue-shifts, typically reached 500 km/s, and even higher velocities (1000 km/s) in some of the galaxies. In general, CLs follow the same pattern of rotation curves as low-ionisation lines like [OIII]. From a direct comparison between the radio and the CL emission we find that neither the strength nor the kinematics of the CLs scale in any obvious and strong way with the radio jets. Moreover, the similarity of the flux distributions and kinematics of the CLs and low-ionisation lines, the low temperatures derived for the gas, and the success of photoionisation models to reproduce, within a factor of few, the observed line ratios, point towards photoionisation as the main driving mechanism of CLs.Comment: Accepted for publication in MNRAS. 27 pages, 21 figures, 4 table

NGC6240: Merger-Induced Star Formation & Gas Dynamics

We present spatially resolved integral field spectroscopic K-band data at a resolution of 0.13" (60pc) and interferometric CO(2-1) line observations of the prototypical merging system NGC6240. Despite the clear rotational signature, the stellar kinematics in the two nuclei are dominated by dispersion. We use Jeans modelling to derive the masses and the mass-to-light ratios of the nuclei. Combining the luminosities with the spatially resolved Br-gamma equivalent width shows that only 1/3 of the K-band continuum from the nuclei is associated with the most recent star forming episode; and that less than 30% of the system's bolometric luminosity and only 9% of its stellar mass is due to this starburst. The star formation properties, calculated from typical merger star formation histories, demonstrate the impact of different assumptions about the star formation history. The properties of the nuclei, and the existence of a prominent old stellar population, indicate that the nuclei are remnants of the progenitor galaxies' bulges.Comment: 18 pages, 14 figures. Accepted for publication in A&

Absorption Properties and Evolution of Active Galactic Nuclei

Intrinsic absorption is a fundamental physical property to understand the evolution of active galactic nuclei (AGN). Here a sample of 1290 AGN, selected in the 2-10 keV band from different flux-limited surveys with very high optical identification completeness is studied. The AGN are grouped into two classes, unabsorbed (type-1) and absorbed (type-2), depending on their optical spectroscopic classification and X-ray absorption properties, using hardness ratios. Utilizing the optical to X-ray flux ratios, a rough correction for the ~8% redshift incompleteness still present in the sample is applied. A strong decrease of the absorbed fraction with X-ray luminosity is found. This can be represented by an almost linear decrease from ~80% to ~20% in the luminosity range log L_X=42-46 and is consistent with similar derivations in the optical and MIR bands. A significant increase of the absorbed fraction with redshift is found, which can be described by a power law with a slope ~(1+z)^{0.62+/-0.11}, saturating at a redshift of z~2. A simple power law fit ~(1+z)^{0.48+/-0.08} over the whole redshift is also marginally consistent with the data. The variation of the AGN absorption with luminosity and redshift is described with higher statistical accuracy and smaller systematic errors than previous results. The findings have important consequences for the broader context of AGN and galaxy co-evolution. Here it is proposed that the cosmic downsizing in the AGN population is due to two different feeding mechanisms: a fast process of merger driven accretion at high luminosities and high redshifts versus a slow process of gas accretion from gravitational instabilities in galactic disks rebuilding around pre-formed bulges and black holes.Comment: 18 pages, 11 figures, A&A (in press

Practical access to planar chiral 1,2-(α-Ketotetramethylene)- ferrocene by non-enzymatic kinetic resolution and conclusive confirmation of its absolute configuration

The asymmetric transfer hydrogenation (ATH) of racemic 1,2-(α-ketotetramethylene)ferrocene using the [N-(tosyl)-1,2-diphenylethylendiamine]ruthenium(II) complex [TsDPEN-Ru(II)] as catalyst takes place with a high level of kinetic resolution to deliver the ketone in up to 99% ee. The X-ray crystallographic structure of a derivative of the alcohol co-product serves to confirm conclusively both the absolute configuration of 1,2-(α-ketotetramethylene)ferrocene and the endo-reduction selectivity