bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Full Cycle in the Evolution of a Classical Nova
Authors: Prialnik D. 
Published: July 2016

AbstractA classical nova model was evolved through a complete cycle, i.e. accretion leading to outburst, mass loss and again accretion, ending in another outburst, by means of an implicit Lagrangian hydrodynamic code, which included diffusion (concentration, pressure and thermal terms), as well as an extensive nuclear reactions network between 28 isotopes of C, N, O, F, Ne, Na, Mg and Al. The initial model was a 1.25 M⊙ C-O white dwarf (WD) and the accretion rate assumed was 10−11 M⊙/yr. For more details of this calculation, see Prialnik (l986).
Low-Mass X-Ray Binaries in the LMC
Authors: Pakull M.W. , Beuermann K. , Angebault L.P. , Bianchi L. 
Published: July 2016

AbstractWe report results on three low-mass X-ray binaries (LMXB) in the LMC, obtained with EXOSAT, IUE and ground-based (ESO) telescopes: LMC X-2 which appears to be “Sco X-l”-like, LHG 83 and LHG 87. The latter are two weaker sources first detected in the course of the HEAO-B LMC survey. They have faint optical counterparts of which LHG 87 was only recently identified by us. In X-rays, they are characterized by ultrasoft X-ray spectra possibly characteristic of black-hole primaries. LHG 83 furthermore shows evidence for X-ray ionization of the surrounding interstellar medium, similar to the He III region around the black-hole candidate LMC X-l. X-ray binaries with masses of compact objects in excess of 3 M⊙ and ultrasoft X-ray spectra are comparatively frequent in the LMC. We suggest that subcritical accretion onto black holes takes place in LHG 83 and LHG 87.
Nāṣīr Ad-Dīn on Determination of the Declination Function
Authors: Hamadani-Zadeh Javad 
Published: July 2016

A commentary, on the spherical astronomy in the Zīj-i Īlkhanī[1], written by the famous Naṣīr ad-Dīn aṭ-Ṭusī (c. 1270) would be an important contribution to the history of medieval astronomy. But we postpone this and attempt here to describe the contents of the third and fourth sections of Treatise III of this zīj. We hope that it will serve to elucidate a small part of this work, which has remained unexploited. I have made a preliminary English translation of the entire Zīj-i Īlkhanī, which awaits final revision and preparation for publication.The rules explained verbally and without proof by Naṣīr ad-Dīn in the sections under consideration are similar to the ones described by Kāshi in his Zīj-i khāqānī and analysed by E. S. Kennedy in [2]. Therefore, we do not present our proofs of the rules, but refer the reader to [2].
Machine-Processing of Objective-Prism Plates at the Royal Observatory, Edinburgh
Authors: Clowes Roger G 
Published: July 2016

AbstractThis paper reviews the methods and early results of work in progress at the Royal Observatory, Edinburgh that involves the machine-processing of objective-prism plates. This work is in two categories: (i) semi-automated galaxy redshifts, and (ii) automated quasar detection. The galaxy redshifts are used, for example, to determine the radial velocities of clusters, to test cluster membership, to reveal superimposed clusters, and to reveal connecting bridges between clusters. Automated quasar detection uses selection criteria that are known, pre-defined and rigidly maintained to select complete samples of quasars. Unlike the earlier visual samples of optically-selected quasars these new samples are well suited to work in cosmology and the collective properties of quasars.
The Application of Optical Fibre Technology to Schmidt Telescopes
Authors: Dawe J.A. , Watson F.G. 
Published: July 2016

AbstractThe potential of the Schmidt optical system, when combined with optical fibres and linear detectors, is assessed. Recent work on the use of optical fibres at the U.K. Schmidt Telescope is described together with anticipated developments. In conclusion, there is a speculative consideration of the construction of a large, altazimuth Schmidt telescope (LAST).
Objective-Prism Galaxy Redshifts in Fields Around the South Galactic Pole
Authors: Parker Q.A. , MacGillivray H.T. , Dodd R.J. , Cooke J.A. , Beard S.M. , Kelly B.D. , Emerson D. 
Published: July 2016

AbstractMeasurements made with the COSMOS machine on deep objectiveprism photographs taken with the UK 1.2m Schmidt Telescope are being used to obtain approximate redshifts (accurate to ~ 0.01 in z) for large numbers of galaxies in fields near the South Galactic Pole. The data are suitable for investigations of the distribution of galaxies, such as the detection of large-scale density enhancements or voids.
Ground Based Developments - Reduction Systems
Authors: Grosbøl P.J. 
Published: July 2016

AbstractThe reduction of Schmidt plates is divided into scanning the plates, processing the data, and analyzing the results. At least two new measuring machines for analyzing Schmidt plates are being designed which will increase the total throughput to over 10 plates per day. The developments of microprocessors and mass storage open new possibilities for faster and cheaper processing of these large amount of data. Finally, the introduction of DataBase Management and Table Data systems will make it easier for astronomers to analyze the extracted informations. With these new developments the aim to make a detailed analysis the plates at the same rate at which they are obtained can be achieved within this decade.
The Cu I And Zn I-Like Spectra of Pr, Eu, Gd, Dy And Yb Emitted by a Tokamak Plasma in the 50–200 Å Range
Authors: Hodge W.L. , Finkenthal M. , Moos H.W. , Lippmann S. , Huang L.K. , Bar-Shalom A. , Klapisch M. 
Published: July 2016

AbstractSpectra of rare earth elements, praseodymium, europium, gadolinium, dysprosium and ytterbium (Z=59 to Z=70) have been recorded from a high temperature (Te=1–1.4 keV) - low density (ne=1013cm−3) tokamak plasma, in the 50–200 Å range. The absolute brightnesses of the lines originating in 4–4 transitions of Cu I and Zn I-like ions of the above mentioned elements have been measured by means of a photometrically calibrated grazing incidence spectrometer. Newly identified Cu I-like, 4s2S1/2-4p2P1/2transitions in Pr30+, Eu34+, Gd35+, Dy37+and Yb41, and intercombination transitions 4s21S0-4s4p3P1, in the Zn I-like ions of the mentioned elements are presented. The identifications are based on interpolation of previous experimental results, ab initio energy level computations using the RELAC code and are substantiated by the time histories of individual spectral lines. The experimental line intensities of the Cu I and Zn I-like ions are compared with those predicted by a collisional-radiative model under the conditions of the tokamak plasma.
Space Resolved Measurements of the Emission of Intermediate and High Ionization States Obtained from Vacuum Spark Plasmas Using Xuv Multilayer Mirrors and a RbAP Crystal
Authors: Finkenthal M. , Stutman D. , Schwob J.L. , Underwood J.H. 
Published: July 2016

AbstractThe spatial extent of the regions from which lines of the Intermediate, NeI-like and high Li I-llke Ionization states of Ti, V, Fe, Co, and Ni, are emitted in a low inductance high-current vacuum spark plasma, has been determined using multilayer mirrors and a RbAP crystal. The spectra have been recorded in the 10–30 Å range. The main conclusion of the present work is that the intermediate ionization states are emitted from an extended plasma region, of the order of 200 microns, while the highly ionized states are formed, as it has been previously stated, In the minute plasma pinch.
Effect on Deuteron Temperature on Iron Forbidden Line Intensities in RF-Heated Tokamak Plasmas
Authors: Sato K. , Suckewer S. , Wouters A. 
Published: July 2016

AbstractTwo line ratios, the forbidden line at 845.5 Å to the allowed line at 135.7 Å in Fe XXII and the forbidden line at 592.1 Å to the forbidden line at 1118.2 Å in Fe XIX, have been measured as ion temperature-sensitive line ratios during rf heating in the Princeton Large Torus. The results indicate that deuteron collisions in plasmas of high deuteron temperature have a noticeable effect on the intensity of the forbidden lines. Measured relative intensities are compared with values from level population calculations which include deuteron collisional excitation between the levels of the ground configuration. The agreement between the observed and calculated ratios is within 30%. A method for deuteron (or proton) temperature measurement in tokamak plasmas is discussed.1More details about this experiment can be found in Ref. 2.
Oscillator Strength Measurements in the Vacuum-Ultraviolet by the Emission Method
Authors: Goldbach C. , Nollez G. 
Published: July 2016

AbstractThe principles and the realization of an experiment devoted to oscillator strength measurements in the vacuum-ultraviolet by the emission method are briefly presented. The results obtained for the strong multiplets of neutral nitrogen and carbon in the 1200-2000 Å range yield an absolute scale of oscillator strengths in good agreement with the most recent calculations.
Diagnostics of Gold Laser Plasmas
Authors: Gauthier J.C. , Geindre J.P. , Monier P. , Chenais-Popovics C. , Tragin N. , Klapisch M. , Bar-Shalom A. 
Published: July 2016

AbstractIn order to achieve a nickel-like X ray laser scheme we need a tool to determine the parameters which characterise the high-Z plasma. The aim of this work is to study gold laser plasmas and to compare experimental results to a collisional-radiative model which describes nickel-like ions. The electronic temperature and density are measured by the emission of an aluminium tracer. They are compared to the predictions of the nickel-like model for pure gold. The results show that the density and temperature can be estimated in a pure gold plasma.
XUV Emission Features from the Livermore Soft X-Ray Laser Experiments
Authors: Eckart M.J. , Scofield J.H. , Hazi A.U. 
Published: July 2016

AbstractThe measured wavelengths in the soft x-ray region for 3p to 3s and 3d to 3p transitions in neon-, sodium-, and magnesium-like selenium are presented. The experimental results for the neon-like ions are compared to theoretical wavelength values and with values extrapolated along the isoelectronic sequence. The ions were contained in a plasma heated in a line-focus of a Nd-glass laser. The measurements were made with a time-gated microchannel-plate-intensified grazing incidence spectrograph.
The Dynamical State of the Atmosphere of the Supergiant Alpha Cygni (A2 Iae) Derived from High-Resolution Ultraviolet Spectra
Authors: Boer B. , de Jager C. , Nieuwenhuijzen H. 
Published: July 2016

AbstractIn order to study the apparent near instability of supergiant atmospheres high-resolution (λ/Δ λ = 8×104) BUSS (Balloon-borne Ultraviolet Stellar Spectrometer) spectra of the supergiant Alpha Cyg have been investigated. Equivalent widths of lines yield the variation of the line-of-sight microturbulent velocity component ζµwith optical depth τ. We find at τ5= 0.1: ζµequal to the velocity of sound. The consequent turbulent acceleration is directed outward, it increases outward and is about half the effective acceleration at τ5= 0.01. The macroturbulent velocity profile is double peaked with up- and downward velocities of 14 km s−1. We suggest that these motions are stochastic pulsations of large elements. At any time there are 30 to 40 such elements on the visible disk.
Optical Shop Testing of Liquid Mirrors
Authors: Borra E.F. , Beauchemin M. , Arsenault R. , Lalande R. 
Published: July 2016

AbstractBorra (1982) has argued that it is scientifically useful and technically feasible to build very large optical telescopes (diameters over 15 meters) having as primary mirror a rotating container filled with mercury. We report here the results of various optical tests on prototype liquid mirrors. The results are very encouraging and seem to indicate that large liquid mirrors are feasible.
A Method to Estimate Fried's Seeing Parameter from a Time Series of Arbitrary Resolved Structures Imaged Through the Atmosphere
Authors: von der Lühe O. 
Published: July 2016

AbstractOne of the major fields of application of speckle-interferometric and speckle-imaging techniques is the photometry of astronomical objects exhibiting structure smaller than the seeing limit. The accuracy of the photometry depends critically on the accuracy to which the modulation transfer function (MTF), that describes the atmospheric-telescopic attenuation of the Fourier amplitudes of the object under consideration, is known. The estimation of the effective MTF is especially difficult when no known reference object is within the field of view.A method is presented that allows to estimate the effective MTF from the observation of arbitrary structure with the use of FRIED-KORFF theory. The ratio of the squared modulus of the average Fourier transform and the average power spectrum serves as an estimator for the FRIED parameter r0. To a first approximation, this ratio is independent from the observed object. Additionally, the behaviour of the ratio in regions beyond the seeing limit in the Fourier plane may be analyzed to obtain an estimate of the speckle interferometry signal-to-noise ratio. The basic concept of the ratio method will be described, its accuracy will be discussed. First results on the application of the ratio method to observations of solar granulation will be presented.
Speckle Interferometry, Speckle Masking, Speckle Spectroscopy and Speckle Frame Selection
Authors: Weigelt Gerd 
Published: July 2016

AbstractHigh-resolution speckle imaging is one of the most fascinating possibilities of a Very Large Telescope (VLT). Various speckle methods can yield a resolution of about 0.01" with a 8-m to 10-m VLT. As exiting as the resolution is the limiting magnitude of the speckle methods. The limiting magnitude is extremely seeingdependent. The following limiting magnitudes are possible with speckle interferometry, speckle masking and speckle spectroscopy:4" seeing: limiting magnitude 152" seeing: limiting magnitude 17.51" seeing: limiting magnitude 20 (!)
Advanced Wide-Field Broad-Passband Refracting Field Correctors for Large Telescopes
Authors: Epps H.W. , Angel J.R.P. , Anderson E. 
Published: July 2016

AbstractA preliminary 30-arcmin prime focus (f/2.0) refracting field corrector system for the University of California Ten-Meter Telescope (UC TMT) is presented which features 1/4-arcsec images containing more than 80% of the energy, over limited passbands within the wavelength range λ3300Å to λ1.0µ. Provision has been made in this system for an atmospheric dispersion corrector (ADC) but same has not yet been realized. Optical elements herein are small enough that this design could be scaled up to a Fifteen-Meter NNTT/SMT.A compact 40-arcmin internal Cassegrain (f/1.75 hyperbola to f/5.0) broad-passband (λ3300Å to λ1.0µ) corrector, suitable for imaging and multi-object spectroscopy at the UC TMT, is presented which features 1/4-arcsec images containing more than 90% of the energy when averaged over field angle and color.Three 60-arcmin external Cassegrain correctors for 300-inch f/1.8 and f/2.0 parabolic primary mirrors are presented which are suitable for a Fifteen-Meter NNTT/MMT. Image quality is comparable to the UC TMT Cassegrain corrector and it exceeds that of the UC TMT preliminary prime focus corrector system by a substantial margin. Each of these correctors contains an ADC which has been implemented in one example, eliminating 4.0 arcsec of differential atmospheric refraction with an rms residual of +/-0.10 arcsec over the broad passband (λ3300Å to λ1.0µ). A 60-arcmin external Cassegrain (f/1.8 extreme hyperbola to f/4.5) corrector with ADC yields yet a factor two in image quality but said hyperbolic primary mirror would be incompatible with angular field requirements in the thermal infrared.A (300-inch) 40-arcmin external Cassegrain (f/1.0 parabola to f/4.0) broad-passband (λ3300Å to λ1.0µ) corrector with ADC is presented. Image quality is comparable to the previous Cassegrain correctors. The practicality of this design, together with recent advances in optical manufacturing capability of large, fast, nonspherical optics, suggests that relatively inexpensive compact telescopes of very large collecting area may be possible in the near future.
Prospects for Fibreoptics in Future Telescope Instrumentation
Authors: Lund Glenn 
Published: July 2016

The importance and applied use of fibreoptics in astronomy has received rapidly growing attention in the past 5 years, particularly for instrumentation where the lightness, flexibility and simplicity of fibres, compared with classical optical systems, can be exploited to full advantage.Angel and Angel et al, who seem to be the first to have used an optical fibre to link a telescope to an instrument, also made the first proposal for the construction of a VLT (FLOAT) consisting of 40 independent mirrors linked to a single instrument via optical fibres. Since that time many authors, including Connes, Serkowski et al, Hubbard et al, Heacox, Hill et al, Vanderriest, Courtes, Tubbs et al, Gray, Lund et al, Schiffer, Watson et al, Vanderriest et al, and Felenbock et al, have proposed or reported various applications involving fibres with astronomical instrumentation.
Cepheid-like Supergiants in the Halo
Authors: Sasselov D. D. 
Published: July 2016

AbstractThe newly proposed UU Her-type stars are discussed; their main features being long-period variability and high galactic latitude. It is unlikely that the UU Her stars originated in the plane of the galaxy as they are now located more than a kiloparsec above it. An alternative explanation of their normal Population I characteristics must be looked for.
The Effects of Convection in RR Lyrae Stars
Authors: Stellingwerf R. F. 
Published: July 2016

AbstractThe effect of convection in RR Lyrae stars has been investigated using nonlinear models that include the effects of time dependence, turbulent pressure, convective overshooting, and convection-pulsation interaction. The convective structure reduces to that of mixing-length theory in the limit of no time dependence and thick convective zones. Initial tests suggested that convection has an important effect on the stability and pulsation mode of these stars. We now have investigated the nonlinear nature of convection at limiting amplitude. Convection serves as a limiting amplitude mechanism for these stars by causing turbulence near the phase of minimum radius that damps the driving. A comparison with Geneva observations of RR Lyrae shows good agreement in the phase dependence and amplitude of the turbulent motions.
Perceived stress and quality of life in dementia patients and their caregiving spouses: does dyadic coping matter?
Authors: Häusler Andreas , Sánchez Alba , Gellert Paul , Deeken Friederike , Rapp Michael A. , Nordheim Johanna 
Published: July 2016

ABSTRACTBackground:Given the well-established association between perceived stress and quality of life (QoL) in dementia patients and their partners, our goal was to identify whether relationship quality and dyadic coping would operate as mediators between perceived stress and QoL.Methods:82 dyads of dementia patients and their spousal caregivers were included in a cross-sectional assessment from a prospective study. QoL was assessed with the Quality of Life in Alzheimer's Disease scale (QoL-AD) for dementia patients and the WHO Quality of Life-BREF for spousal caregivers. Perceived stress was measured with the Perceived Stress Scale (PSS-14). Both partners were assessed with the Dyadic Coping Inventory (DCI). Analyses of correlation as well as regression models including mediator analyses were performed.Results:We found negative correlations between stress and QoL in both partners (QoL-AD:r= −0.62; p < 0.001; WHO-QOL Overall:r= −0.27; p = 0.02). Spousal caregivers had a significantly lower DCI total score than dementia patients (p < 0.001). Dyadic coping was a significant mediator of the relationship between stress and QoL in spousal caregivers (z= 0.28; p = 0.02), but not in dementia patients. Likewise, relationship quality significantly mediated the relationship between stress and QoL in caregivers only (z= −2.41; p = 0.02).Conclusions:This study identified dyadic coping as a mediator on the relationship between stress and QoL in (caregiving) partners of dementia patients. In patients, however, we found a direct negative effect of stress on QoL. The findings suggest the importance of stress reducing and dyadic interventions for dementia patients and their partners, respectively.
TWEAK favors phosphate-induced calcification of vascular smooth muscle cells through canonical and non-canonical activation of NFκB
Authors: Hénaut L , Sanz A B , Martin-Sanchez D , Carrasco S , Villa-Bellosta R , Aldamiz-Echevarria G , Massy Z A , Sanchez-Nino M D , Ortiz A 
Published: July 2016

AbstractVascular calcification (VC) is associated with increased cardiovascular mortality in aging, chronic kidney disease (CKD), type 2 diabetes mellitus (T2DM) and atherosclerosis. TNF-like weak inducer of apoptosis (TWEAK) recently emerged as a new biomarker for the diagnosis and prognosis of cardiovascular diseases. TWEAK binding to its functional receptor Fn14 was reported to promote several steps of atherosclerotic plaque progression. However, no information is currently available on the role of TWEAK/Fn14 on the development of medial calcification, which is highly prevalent in aging, CKD and T2DM. This study explored the involvement of TWEAK in human vascular smooth muscle cells (h-VSMCs) calcification in vitro. We report that TWEAK binding to Fn14 promotes inorganic phosphate-induced h-VSMCs calcification, favors h-VSMCs osteogenic transition, decreasing acta2 and myh11 and increasing bmp2 mRNA and tissue non-specific alkaline phosphatase (TNAP), and increases MMP9 activity. Blockade of the canonical NFκB pathway reduced by 80% TWEAK pro-calcific properties and decreased osteogenic transition, TNAP and MMP9 activity. Blockade of non-canonical NFκB signaling by a siRNA targeting RelB reduced by 20% TWEAK pro-calcific effects and decreased TWEAK-induced loss of h-VSMCs contractile phenotype and MMP9 activity, without modulating bmp2 mRNA or TNAP activity. Inhibition of ERK1/2 activation by a MAPK kinase inhibitor did not influence TWEAK pro-calcific properties. Our results suggest that TWEAK/Fn14 directly favors inorganic phosphate-induced h-VSMCs calcification by activation of both canonical and non-canonical NFκB pathways. Given the availability of neutralizing anti-TWEAK strategies, our study sheds light on the TWEAK/Fn14 axis as a novel therapeutic target in the prevention of VC.