Stellar laboratories. V. The Xe VI ultraviolet spectrum and the xenon abundance in the hot DO-type white dwarf RE0503-289

For the spectral analysis of spectra of hot stars with a high resolution and high signal-to-noise ratio (S/N), advanced non-local thermodynamic equilibrium (NLTE) model atmospheres are mandatory. These are strongly dependent on the reliability of the atomic data that are used for their calculation. Reliable Xe VI oscillator strengths are used to identify Xe lines in the ultraviolet spectrum of the DO-type white dwarf RE0503-289 and to determine its photospheric Xe abundance. We publish newly calculated oscillator strengths that are based on a recently measured Xe VI laboratory line spectrum. These strengths were used to consider their radiative and collisional bound-bound transitions in detail in our NLTE stellar-atmosphere models to analyze Xe VI lines exhibited in high-resolution and high S/N UV observations of RE0503-289. We identify three hitherto unknown Xe VI lines in the ultraviolet spectrum of RE0503-289 and confirm the previously measured photospheric Xe abundance of this white dwarf (log Xe = -4.2 +/- 0.6). Reliable measurements and calculations of atomic data are prerequisite for stellar-atmosphere modeling. Observed Xe VI line profiles in the ultraviolet spectrum of the white dwarf RE0503-289 were well reproduced with the newly calculated Xe VI oscillator strengths.Comment: 3 pages, 4 figure

Implications of Contemporary Leadership Models on Sales Management

As organizations have discovered that they cannot solely compete on price, product, quality, or technology, organizations have sought the use of optimum leadership models to assist with competition and survival. After examining the evolution of three contemporary leadership models: Spiritual Leadership, Primal Leadership, and Innovative Leadership, it is shown that these models offer sustenance in various ways for organizations and employees. Furthermore, because of the introduction and practice of Spiritual Leadership, Primal Leadership, and Innovative Leadership, specific implications exist for sales management as related to their sales reps and to their customers

Destruction of a protected habitat by an invasive alien species: the case of Cydalima perspectalis (Walker, 1859) in the box tree formations of Liguria (North-West Italy) (Lepidoptera: Crambidae)

The box tree moth, Cydalima perspectalis (Walker, 1859), an invasive alien species of Asian origin associated with box trees, gained immediate attention in Europe due to the damage caused to ornamental stands and its rapid spread. However, its effects on natural box tree formations remained poorly investigated, especially in Southern Europe. In Liguria (North-West Italy), attacked xerotermophilous box tree formations on rocky substrate, a protected habitat (5110) after the Natura 2000 EU 92/43 Directive, seriously endangering its long-term survival. Since detection in 2013, this species defoliated almost the whole area covered by habitat 5110, until experiencing a population crash after depleting its only trophic resource. We present here the evolution of the invasion and the population dynamics of this invasive alien species in Liguria during the years 2016-2017

New spectroscopic data for atomic tungsten XIV

The thirteen times ionized tungsten is isoelectronic with PmI. Wavelengths and transition probabilities for the 5s-5p and 5p-5d transitions of WXIV, identifying the ground state as 4f13 5s2 2F7/2 were calculated. Both, a relativistic Hartree Fock approach, including core-polarization effects, and a purely relativistic multiconfiguration Dirac-Fock method were used for the calculations. Particularly, 5s-5p transitions were compared with experimental results obtained with VUV electron beam ion trap (EBIT) spectroscopy583CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESnão temnão tem17th International conference on the physics of highly charged ionsThis research was supported by the Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina, by the Coordenaçăo de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) and by the Conselho Nacional de Pesquisa (CNPq), Brazil. The Comisión de Investigaciones Científcas de la Provincia de Buenos Aires (CIC), where J. G. Reyna Almandos and M. Raineri are researchers, is also gratefully acknowledge

Field Localization and Enhancement of Phase Locked Second and Third Harmonic Generation in Absorbing Semiconductor Cavities

We predict and experimentally observe the enhancement by three orders of magnitude of phase mismatched second and third harmonic generation in a GaAs cavity at 650nm and 433nm, respectively, well above the absorption edge. Phase locking between the pump and the harmonics changes the effective dispersion of the medium and inhibits absorption. Despite hostile conditions the harmonics become localized inside the cavity leading to relatively large conversion efficiencies. Field localization plays a pivotal role and ushers in a new class of semiconductor-based devices in the visible and UV ranges

Staphylococcal trafficking and infection-from 'nose to gut' and back

Staphylococcus aureus is an opportunistic human pathogen, which is a leading cause of infections worldwide. The challenge in treating S. aureus infection is linked to the development of multidrug-resistant strains and the mechanisms employed by this pathogen to evade the human immune defenses. In addition, S. aureus can hide asymptomatically in particular ‘protective’ niches of the human body for prolonged periods of time. In the present review, we highlight recently gained insights in the role of the human gut as an endogenous S. aureus reservoir next to the nasopharynx and oral cavity. In addition, we address the contribution of these ecological niches to staphylococcal transmission, including the roles of particular triggers as modulators of the bacterial dissemination. In this context, we present recent advances concerning the interactions between S. aureus and immune cells to understand their possible roles as vehicles of dissemination from the gut to other body sites. Lastly, we discuss the factors that contribute to the switch from colonization to infection. Altogether, we conclude that an important key to uncovering the pathogenesis of S. aureus infection lies hidden in the endogenous staphylococcal reservoirs, the trafficking of this bacterium through the human body and the subsequent immune responses

Revised and extended analysis of five times ionized xenon, Xe Vi

A capillary discharge tube was used to record the Xe spectrum in the 400-5500 Å region. A set of 243 lines of the Xe VI spectrum was observed, and 146 of them were classified for the first time. For all known lines, we calculated the weighted oscillator strengths (gf) and weighted transition probabilities (gA) using the configuration interaction in a relativistic Hartree-Fock approach. The energy matrix was calculated using energy parameters adjusted to fit the experimental energy levels. Core polarization effects were taken into account in our calculations. Experimental energy values and calculated lifetimes are also presented for a set of 88 levels. From these levels, 32 were classified for the first time and 33 had their values revised. Our analysis of the 5s5p5d and 5s5p6s configurations was extended in order to clarify discrepancies among previous works216