Anomalous Raman scattering from phonons and electrons of superconducting FeSe0.82_{0.82}

We report interesting anomalies in the temperature dependent Raman spectra of FeSe$_{0.82}$ measured from 3K to 300K in the spectral range from 60 to 1800 cm$^{-1}$ and determine their origin using complementary first-principles density functional calculations. A phonon mode near 100 cm$^{-1}$ exhibits a sharp increase by $\sim$ 5% in frequency below a temperature T$_s$ ($\sim$ 100 K) attributed to strong spin-phonon coupling and onset of short-range antiferromagnetic order. In addition, two high frequency modes are observed at 1350 cm$^{-1}$ and 1600 cm$^{-1}$, attributed to electronic Raman scattering from ($x^2-y^2$)to $xz$ / $yz$ $d$-orbitals of Fe.Comment: 19 pages, 4 figures, 1 tabl

Disaster financing and poverty traps for poor households: Realities in Northern India

This paper addresses household-level disaster financing strategies of the poor in developing countries within the context of current poverty trap discussions. It presents findings on risk perceptions and loss financing practices in relation to floods and droughts in Uttar Pradesh, India. The study found that, due to financial shocks, the risk of households falling below the subsistence level and into a poverty trap is high. In this context, the paper links current approaches in household welfare-drive disaster risk financing to the survey results and provides policy recommendations

The Structure of the Literary Problem in the Formation of the Local Text Substrate

The article aims to study the structure of the literary problem in the formation of the local text substrate. The study uses the methodology of studying the language when it changes in time and space. The article explains the basics of the methodological support of the translation complex and the structure of its application in private studies of foreign cultures and communicants. The results of the study showed the possibility of interaction between the subjects of linguistic exchange and the dynamics of the translation and literary component. The novelty of the study is determined by the fact that the work defines methods that can be used not only by local researchers but also by foreign-speaking communicants. The research results can be used in practical activities to bridge the gap between understanding the local text in translation studies and its structuring in the local versions of individual authors

Vacuum Induced Coherences in Radiatively Coupled Multilevel Systems

We show that radiative coupling between two multilevel atoms having near-degenerate states can produce new interference effects in spontaneous emission. We explicitly demonstrate this possibility by considering two identical V systems each having a pair of transition dipole matrix elements which are orthogonal to each other. We discuss in detail the origin of the new interference terms and their consequences. Such terms lead to the evolution of certain coherences and excitations which would not occur otherwise. The special choice of the orientation of the transition dipole matrix elements enables us to illustrate the significance of vacuum induced coherence in multi-atom multilevel systems. These coherences can be significant in energy transfer studies.Comment: 13 pages including 8 figures in Revtex; submitted to PR

PKS 0537-441: extended [O II] emission and a binary QSO?

We present high-resolution imaging and low-resolution spectroscopy of the BL Lac object PKS 0537-441 (z = 0.893) and its environment. The observations were designed to clarify, whether the properties of PKS 0537-441 are affected by gravitational microlensing, or whether PKS 0537-441 and its environment act as a lensing system itself. Our observations show that neither case seems to be likely. We did not find a galaxy along the line-of-sight to the BL Lac as claimed previously, our spectroscopy shows that none of the four closest companion galaxies is at high redshift. Two of the four nearby companion galaxies to PKS 0537-441 are within 200 km/s of the systemic velocity of the BL Lac (z = 0.892 and 0.895, respectively). The third companion galaxy is at higher redshift (z = 0.947). The fourth companion galaxy shows evidence of Mg II absorption redwards of its systemic velocity and is perhaps a mini low ionization BAL QSO at z = 0.885. If the latter can be confirmed, PKS 0537-441 is the first BL Lacertae object being a member of a binary Quasar. We also detected extended [O II] emission in the off-nuclear spectrum of PKS 05371-441, which is most likely due to photoionization from the active nucleus. Alternatively, the extended [O II] emission is due to jet-cloud interaction with the counterjet of PKS 0537-441. Our clustering analysis indicates that PKS 0537-441 is located in a cluster environment as rich as Abell type 0-1. This is supported by the detection of four galaxies in the field with similar redshifts as the BL Lac (Delta z < 0.002). We found serendipitously even more galaxies at somewhat higher redshifts (z = 0.9-1). Thus, PKS0537-441 might be located in front of a galaxy cluster at somewhat higher redshift or even be part of a large-scale structure with an extension towards the BL Lac.Comment: 13 pages, 9 figures, accepted for publication in A&

The Nature of Composite LINER/HII Galaxies, As Revealed from High-Resolution VLA Observations

A sample of 37 nearby galaxies displaying composite LINER/HII and pure HII spectra was observed with the VLA in an investigation of the nature of their weak radio emission. The resulting radio contour maps overlaid on optical galaxy images are presented here, together with an extensive literature list and discussion of the individual galaxies. Radio morphological data permit assessment of the ``classical AGN'' contribution to the global activity observed in these ``transition'' LINER galaxies. One in five of the latter objects display clear AGN characteristics: these occur exclusively in bulge-dominated hosts.Comment: 31 pages, 27 figures, accepted by ApJ

Growth, structure analysis and anisotropic superconducting properties of MgB2 single crystals

Here we report the growth of sub-millimeter MgB2 single crystals of various shapes under high pressure in Mg-B-N system. Structure refinement using a single-crystal X-ray diffraction analysis gives lattice parameters a=3.0851(5) A and c=3.5201(5) A with small reliability factors (Rw =0.025, R=0.018), which enables us to analyze the Fourier and Fourier difference maps. The maps clearly show the B sp2 orbitals and covalency of the B-B bonds. The sharp superconducting transitions at Tc =38.1-38.3K were obtained in both magnetization (DTc =0.6K) and resistivity (DTc <0.3K) measurements. Resistivity measurements with magnetic fields applied parallel and perpendicular to the Mg and B sheets reveal the anisotropic nature of this compound, with upper critical field anisotropy ratio of about 2.7.Comment: 9 pages, 5 figures and 1 tabl

Super-conducting critical fields and anisotropy of a MgB2 single crystal

Despite the intense activity in the year since the discovery of superconductivity in MgB2, key parameters, in particular the upper and lower critical fields Hc2 and Hc1 and their anisotropies, are not well-established, largely because of the difficulty of growing MgB2 crystals. Attempts have been made to deduce these parameters from experiments on polycrystalline material, but they have substantial uncertainties. Hc2 is particularly important for applications, as it is the field which quenches bulk super-conductivity. In terms of understanding MgB2, it is now clear that the conventional electron-phonon interaction is strong enough to account for the high transition temperature Tc, but the consequences of the double super-conducting gap for the anisotropy and its dependence on temperature, are uncertain. Here we describe detailed direct measurements of Hc1(T) and Hc2(T) for the two principal crystallographic directions in a clean single crystal of MgB2. For fields in the c-direction, $\mu_0 H^c_{c1}(0)$ = $0.28 +- 0.01T$ and $\mu_0 H^c_{c2}(0)$ is $3 +- 0.5T$; this ratio of critical fields is rather low and implies that MgB2 is only just a Type II super-conductor. The anisotropies of both critical fields are close to 2.Comment: 3 pages 3 figure

Enhancement of the upper critical field by nonmagnetic impurities in dirty two-gap superconductors

Quasiclassic Uzadel equations for two-band superconductors in the dirty limit with the account of both intraband and interband scattering by nonmagnetic impurities are derived for any anisotropic Fermi surface. From these equations the Ginzburg-Landau equations, and the critical temperature $T_c$ are obtained. An equation for the upper critical field, which determines both the temperature dependence of $H_{c2}(T)$ and the orientational dependence of $H_{c2}(\theta)$ as a function of the angle $\theta$ between ${\bf H}$ and the c-axis is obtained. It is shown that the shape of the $H_{c2}(T)$ curve essentially depends on the ratio of the intraband electron diffusivities $D_1$ and $D_1$, and can be very different from the standard one-gap dirty limit theory. In particular, the value $H_{c2}(0)$ can considerably exceed $0.7T_cdH_{c2}/dT_c$, which can have important consequences for applications of $MgB_2$. A scaling relation is proposed which enables one to obtain the angular dependence of $H_{c2}(\theta)$ from the equation for $H_{c2}$ at ${\bf H}\| c$. It is shown that, depending on the relation between $D_1$ and $D_2$, the ratio of the upper critical field $H_{c2}^\|/H_{c2}^\perp$ for ${\bf H}\| ab$ and ${\bf H}\perp ab$ can both increase and decrease as the temperature decreases. Implications of the obtained results for $MgB_2$ are discussed

Prognostic Role of Gene Mutations in Chronic Myelomonocytic Leukemia Patients Treated With Hypomethylating Agents

Somatic mutations contribute to the heterogeneous prognosis of chronic myelomonocytic leukemia (CMML). Hypomethylating agents (HMAs) are active in CMML, but analyses of small series failed to identify mutations predicting response or survival. We analyzed a retrospective multi-center cohort of 174 CMML patients treated with a median of 7 cycles of azacitidine (n = 68) or decitabine (n = 106). Sequencing data before treatment initiation were available for all patients, from Sanger (n = 68) or next generation (n = 106) sequencing. Overall response rate (ORR) was 52%, including complete response (CR) in 28 patients (17%). In multivariate analysis, ASXL1 mutations predicted a lower ORR (Odds Ratio [OR] = 0.85, p = 0.037), whereas TET2mut/ASXL1wt genotype predicted a higher CR rate (OR = 1.18, p = 0.011) independently of clinical parameters. With a median follow-up of 36.7 months, overall survival (OS) was 23.0 months. In multivariate analysis, RUNX1mut (Hazard Ratio [HR] = 2.00, p = .011), CBLmut (HR = 1.90, p = 0.03) genotypes and higher WBC (log10(WBC) HR = 2.30, p = .005) independently predicted worse OS while the TET2mut/ASXL1wt predicted better OS (HR = 0.60, p = 0.05). CMML-specific scores CPSS and GFM had limited predictive power. Our results stress the need for robust biomarkers of HMA activity in CMML and for novel treatment strategies in patients with myeloproliferative features and RUNX1 mutations. Keywords: Chronic myelomonocytic leukemia, Hypomethylating agents, Somatic mutations, Prognosi