Radio Polarization of the Young High-Magnetic-Field Pulsar PSR J1119-6127

We have investigated the radio polarization properties of PSR J1119-6127, a recently discovered young radio pulsar with a large magnetic field. Using pulsar-gated radio imaging data taken at a center frequency of 2496 MHz with the Australia Telescope Compact Array, we have determined a rotation measure for the pulsar of +842 +/- 23 rad m^-2. These data, combined with archival polarimetry data taken at a center frequency of 1366 MHz with the Parkes telescope, were used to determine the polarization characteristics of PSR J1119-6127 at both frequencies. The pulsar has a fractional linear polarization of ~75% and ~55% at 1366 and 2496 MHz, respectively, and the profile consists of a single, wide component. This pulse morphology and high degree of linear polarization are in agreement with previously noticed trends for young pulsars (e.g., PSR J1513-5908). A rotating-vector (RV) model fit of the position angle (PA) of linear polarization over pulse phase using the Parkes data suggests that the radio emission comes from the leading edge of a conal beam. We discuss PSR J1119-6127 in the context of a recent theoretical model of pulsar spin-down which can in principle be tested with polarization and timing data from this pulsar. Geometric constraints from the RV fit are currently insufficient to test this model with statistical significance, but additional data may allow such a test in the future.Comment: 9 pages, including 6 figures and 1 table. Accepted for publication in Ap

Elastic Behavior of a Two-dimensional Crystal near Melting

Using positional data from video-microscopy we determine the elastic moduli of two-dimensional colloidal crystals as a function of temperature. The moduli are extracted from the wave-vector-dependent normal mode spring constants in the limit $q\to 0$ and are compared to the renormalized Young's modulus of the KTHNY theory. An essential element of this theory is the universal prediction that Young's modulus must approach $16 \pi$ at the melting temperature. This is indeed observed in our experiment.Comment: 4 pages, 3 figure

Crystal nuclei and structural correlations in two-dimensional colloidal mixtures: experiment versus simulation

We examine binary mixtures of superparamagnetic colloidal particles confined to a two-dimensional water-air interface both by real-space experiments and Monte-Carlo computer simulations at high coupling strength. In the simulations, the interaction is modelled as a pairwise dipole-dipole repulsion. While the ratio of magnetic dipole moments is fixed, the interaction strength governed by the external magnetic field and the relative composition is varied. Excellent agreement between simulation and experiment is found for the partial pair distribution functions including the fine structure of the neighbour shells at high coupling. Furthermore local crystal nuclei in the melt are identified by bond-orientational order parameters and their contribution to the pair structure is discussed

Teachers' emotional well-being during the SARS-CoV-2 pandemic with long school closures: a large-scale cross-sectional survey in Northern Italy

Objectives: This study aimed to evaluate the magnitude of emotional burden on teaching staff during the SARS-CoV-2 pandemic in a significantly impacted region. In addition, the correlates of emotional burden were analysed to enable the design of targeted interventions. Study design: This study was a cross-sectional survey. Methods: An electronic survey was administered to the teaching staff at public schools and kindergartens in a specific geographical area. Cross-sectional assessments of pandemic-specific variables were performed using the Pandemic Fatigue Scale, the Depression Anxiety Stress Scale (DASS)-21, the Satisfaction with Life Scale, and the Resilient Coping Scale. DASS-21 results were compared with results from a parallel survey that was representative of the local general population. Results: In total, 3251 teaching staff members participated in the survey. Teachers showed a higher emotional burden for depression, anxiety and stress than the general population during the pandemic. According to a linear regression model, this burden is correlated with the language in which the questionnaires were answered, mistrust towards institutions, specific SARS-CoV-2 anxiety, past infection with SARS-CoV-2, avoidance of information about the pandemic and pandemic fatigue; emotional burden was negatively correlated with measures for life satisfaction, resilience and team atmosphere. Some independent variables were shown to contribute differentially to the variance of depression, anxiety or stress. Conclusions: Emotional distress during the pandemic among teachers is higher than in the general population and correlates with variables that could, at least in principle, be targeted for specific interventions

Система управления персоналом организации на примере обувной сети «Дарина»

Выпускная квалификационная работа 72 с., 5 рис., 13 табл., 40 источников, 3 прил. Ключевые слова: система управления персоналом, персонал, кадры, модели управления персоналом, система стимулирования. Объект исследования – обувная сеть «Дарина». Предмет исследования – предложения по совершенствованию системы управления персоналом в сети магазинов «Дарина». Цель работы – на основе анализа системы управления персоналом в сети магазинов «Дарина» разработать предложения по ее совершенствованию.Graduation thesis 72 p., 5 Fig., 13 tab., 40 sources, 3 ADJ. Key words: personnel management system, personnel, personnel, model of personnel management, system of incentives. The object of study – Shoe network "Darina". Subject of research – proposals for improving the personnel management system in chain stores "Darina". Purpose – based on the analysis of the personnel management system in chain stores "Darina" to develop proposals for its improvement

First decay study of the very neutron-rich isotope Br-93

The decay of the mass-separated, very neutron-rich isotope Br-93 has been studied by gamma-spectroscopy. A level scheme of its daughter Kr-93 has been constructed. Level energies, gamma-ray branching ratios and multipolarities suggest spins and parities which are in accord with a smooth systematics of the N=57 isotones for Z less-equal 40, suggesting the N=56 shell closure still to be effective in Kr isotopes. So far, there is no indication of a progressive onset of deformation in neutron-rich Kr isotopes.Comment: 17 pages, 3 figures, Phys. Rev. C, in prin

Molecular typing of mycobacterium tuberculosis by using nine novel variable-number tandem repeats across the Beijing family and low-copy-number IS6110 isolates

Molecular epidemiological tools for genotyping clinical isolates of Mycobacterium tuberculosis have been developed and used to help track and contain transmission of tuberculosis. We identified 87 short sequence repeat loci within the genome of the M. tuberculosis H37Rv strain. Nine tandem repeats were found to be variable (variable-number tandem repeats (VNTRs)) in a set of 91 isolates. Fifty-seven of the isolates had only four IS6110 bands. The other 34 isolates were members of the Beijing strain family. The number of alleles of each these nine VNTRs was determined by examining each isolate. Six of the loci (Mtb-v1, -v4, -v10, -v15, -v18, and -v20) were able to differentiate the Beijing spoligotype identical isolates into seven distinct genotypes. Five of the loci (Mtb-v3, -v5, -v6, -v10, and -v15) were informative in discriminating the four-band IS6110 restriction fragment length polymorphism isolates from each other. The Nei's diversity values of each marker ranged from 0.02 to 0.59, with the number of alleles ranging from two to eight across the entire strain set. These nine loci provide a useful, discriminatory extension of VNTR typing methods for application to molecular epidemiologic studies of M. tuberculosis

Are models of catalytic removal of O_3 by HO_x accurate? Constraints from in situ measurements of the OH to HO_2 ratio

Measurements of the ratio OH/HO_2, NO, O_3, ClO, and BrO were obtained at altitudes from 15–20 km and latitudes from 15–60°N. A method is presented for interpreting these simultaneous in situ observations that constrains the rates of chemical transformations that 1) are responsible for over half the ozone removal rate in the lower stratosphere via reactions of HO_2 and 2) control the abundance of HO_2 through coupling to nitrogen and halogen radicals. The results show our understanding of the chemical reactions controlling the partitioning of OH and HO_2 is complete and accurate and that the potential effects of “missing chemistry” are strictly constrained in the region of the atmosphere encompassed by the observations. The analysis demonstrates that the sensitivity of the ratio OH/HO_2 to changes in NO is described to within 12% by current models. This reduces by more than a factor of 2 the effect of uncertainty in the coupling of hydrogen and nitrogen radicals on the analysis of the potential effects of perturbations to odd nitrogen in the lower stratosphere

Criterion-Based Grading, Agile Goal Setting, and Course (Un)Completion Strategies

Peer reviewe

The role of HO_x in super- and subsonic aircraft exhaust plumes

The generation of sulfuric acid aerosols in aircraft exhaust has emerged as a critical issue in determining the impact of supersonic aircraft on stratospheric ozone. It has long been held that the first step in the mechanism of aerosol formation is the oxidation of SO_(2) emitted from the engine by OH in the exhaust plume. We report in situ measurements of OH and HO_(2) in the exhaust plumes of a supersonic (Air France Concorde) and a subsonic (NASA ER-2) aircraft in the lower stratosphere. These measurements imply that reactions with OH are responsible for oxidizing only a small fraction of SO_(2) (2%), and thus cannot explain the large number of particles observed in the exhaust wake of the Concorde