772 research outputs found

    Uncertainties in the solar photospheric oxygen abundance

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    The purpose of this work is to better understand the confidence limits of the photospheric solar oxygen abundance derived from three-dimensional models using the forbidden [OI] line at 6300 \AA , including correlations with other parameters involved. We worked with a three-dimensional empirical model and two solar intensity atlases. We employed Bayesian inference as a tool to determine the most probable value for the solar oxygen abundance given the model chosen. We considered a number of error sources, such as uncertainties in the continuum derivation, in the wavelength calibration and in the abundance/strength of Ni. Our results shows correlations between the effects of several parameters employed in the derivation. The Bayesian analysis provides robust confidence limits taking into account all of these factors in a rigorous manner. We obtain that, given the empirical three-dimensional model and the atlas observations employed here, the most probable value for the solar oxygen abundance is log(ϵO)=8.86±0.04\log(\epsilon_O) = 8.86\pm0.04. However, we note that this uncertainty does not consider possible sources of systematic errors due to the model choice.Comment: Accepted for publication in Astronomy and Astrophysic

    Pengaruh Modal Sendiri dan Penerimaan Kredit terhadap Pendapatan Pedagang Kecil di Pasar Simpang Baru Panam Pekanbaru

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    What percentage of the influence of Equity and Acceptance Credit to Small Traders Revenue in Simpang Pasar Baru Panam Pekanbaru. This research was conducted in Pasar Baru Simpang Panam Pekanbaru in May-finished. The method used is descriptive quantitative method. The population in this study are all traders who trade in the market a new intersection panam pekanbaru totaling 320 traders and 10% of the population sampled is 32 respondents. The sampling based on purposive sampling. Data were collected through a questionnaire while analyzed using univariate and bivariate linear regression significant level of 0.05%. Based on the survey results revealed that the own capital and credit acceptance affect the income of traders, it is based on the results of the analysis using SPSS, showed simultannya calculation of F (9125)> F table (4.183) with Sig. (0.001) t table (2.045) and Sig. (0,023) t table (2.045) and Sig. (0.002) <0.05. So it can be concluded that there is significant influence from its own capital and acceptance of credit against the income of small traders in the market panam pekanbaru new intersection. The amount of contributions or donations of their own capital and acceptance of credit to traders income shown by the R Square of 0.386. What this means is that the contribution of the influence of their own capital and acceptance of credit againstincome amounted to 38.6% and the rest of 61.4% are not addressed in this stud

    Thermal Giant Gravitons

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    We study the giant graviton solution as the AdS_5 X S^5 background is heated up to finite temperature. The analysis employs the thermal brane probe technique based on the blackfold approach. We focus mainly on the thermal giant graviton corresponding to a thermal D3-brane probe wrapped on an S^3 moving on the S^5 of the background at finite temperature. We find several interesting new effects, including that the thermal giant graviton has a minimal possible value for the angular momentum and correspondingly also a minimal possible radius of the S^3. We compute the free energy of the thermal giant graviton in the low temperature regime, which potentially could be compared to that of a thermal state on the gauge theory side. Moreover, we analyze the space of solutions and stability of the thermal giant graviton and find that, in parallel with the extremal case, there are two available solutions for a given temperature and angular momentum, one stable and one unstable. In order to write down the equations of motion, action and conserved charges for the thermal giant graviton we present a slight generalization of the blackfold formalism for charged black branes. Finally, we also briefly consider the thermal giant graviton moving in the AdS_5 part.Comment: v1: 32 pages + 11 pages appendices, 13 figures, v2: typos fixed in Sec.2 and other misprints, references adde

    Off-pump HeartMate II Exchange in a Patient with Severe Lower Extremity Peripheral Artery Disease: A Case Report

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    Thrombosis of left ventricular assist device (LVAD) pumps is a serious complication that often requires exchange of the device. A 66-year-old man with severe peripheral vascular disease presented with pump thrombosis of the HeartMate II (HMII) LVAD 1.5 years after implantation. The HMII was exchanged to another HMII through a subcostal incision and without the use of cardiopulmonary bypass. For safety, the patient was prepared for cardiopulmonary bypass by exposing the right subclavian artery and insertion of a 5 FR cannula in the left common femoral vein. The pump was exchanged through a subcostal incision made over the LVAD pump pocket perpendicular to the costal margin. After deairing the pump and graft, LVAD support was resumed, postoperative course was uneventful, and the patient was discharged from the hospital four days later. Re-thrombosis, stroke, and right heart failure are frequent complications after LVAD exchange. Exchange through a subcostal incision with cardiopulmonary bypass backup appears to be safe

    Uniqueness Theorem for Black Hole Space-Times with Multiple Disconnected Horizons

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    We show uniqueness of stationary and asymptotically flat black hole space-times with multiple disconnected horizons and with two rotational Killing vector fields in the context of five-dimensional minimal supergravity (Einstein-Maxwell-Chern-Simons gravity). The novelty in this work is the introduction in the uniqueness theorem of intrinsic local charges measured near each horizon as well as the measurement of local fluxes besides the asymptotic charges that characterize a particular solution. A systematic method of defining the boundary conditions on the fields that specify a black hole space-time is given based on the study of its rod structure (domain structure). Also, an analysis of known solutions with disconnected horizons is carried out as an example of an application of this theorem.Comment: 28 pages, 5 figures. v3: Further improvements on uniqueness theorem, Lemma introduced for clarity of derivation, new quantities introduced to treat special case with zero flux, refs. added, typos fixe

    Inverse Scattering Construction of a Dipole Black Ring

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    Using the inverse scattering method in six dimensions we construct the dipole black ring of five dimensional Einstein-Maxwell-dilaton theory with dilaton coupling a = 2(2/3)^(1/2).The 5d theory can be thought of as the NS sector of low energy string theory in Einstein frame. It can also be obtained by dimensionally reducing six-dimensional vacuum gravity on a circle. Our new approach uses GL(4, R) integrability structure of the theory inherited from six-dimensional vacuum gravity. Our approach is also general enough to potentially generate dipole black objects carrying multiple rotations as well as more exotic multi-horizon configurations

    Ultraspinning instability: the missing link

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    We study linearized perturbations of Myers-Perry black holes in d=7, with two of the three angular momenta set to be equal, and show that instabilities always appear before extremality. Analogous results are expected for all higher odd d. We determine numerically the stationary perturbations that mark the onset of instability for the modes that preserve the isometries of the background. The onset is continuously connected between the previously studied sectors of solutions with a single angular momentum and solutions with all angular momenta equal. This shows that the near-extremality instabilities are of the same nature as the ultraspinning instability of d>5 singly-spinning solutions, for which the angular momentum is unbounded. Our results raise the question of whether there are any extremal Myers-Perry black holes which are stable in d>5.Comment: 19 pages. 1 figur

    Mayo Adhesive Probability Score Does Not Have Prognostic Ability in Locally Advanced Renal Cell Carcinoma

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    Nephrectomy remains standard treatment for renal cell carcinoma (RCC). The Mayo Adhesive Probability (MAP) score is predictive of adherent perinephric fat and associated surgical complexity, and is determined by assessing perinephric fat and stranding. MAP has additionally predicted progression-free survival (PFS), though primarily reported in stage T1-T2 RCC. Here, we examine MAP’s ability to predict overall survival (OS) and PFS in T3-T4 RCC. From our prospectively maintained RCC database, patients that underwent radical nephrectomy (2009-2016) with available abdominal imaging (&lt;90 days preop) and T3/T4 RCC underwent MAP scoring. Survival analyses were conducted with MAP scores as individual (0-5) and dichotomized (0-3 vs 4-5) using Kaplan-Meier method. Multivariable Cox proportional hazard regression models for PFS and OS were built with backward elimination. 141 patients were included. 134 (95%) and 7 (5%) had pT3 and pT4 disease, respectively. 46.1% of patients had an inferior vena cava thrombus. Mean MAP score was 3.22±1.52, with 75 (53%) patients having a score between 0-3 and 66 (47%) having a score of 4-5. Both male gender (p=0.006) and clear cell histology (p=0.012) were associated with increased MAP scores. On Kaplan-Meier and multivariable analysis, no significant associations were identified between MAP and PFS (HR=1.01, 95% CI 0.85-1.20, p=0.93) or OS (HR=1.01, 95% CI 0.84-1.21, p=0.917). In this cohort of patients with locally advanced RCC, high MAP scores were not predictive of worse PFS or OS

    Swift follow-up of unidentified X-ray sources in the XMM-Newton Slew Survey

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    We present deep Swift follow-up observations of a sample of 94 unidentified X-ray sources from the XMM-Newton Slew Survey. The X-ray Telescope on-board Swift detected 29% of the sample sources; the flux limits for undetected sources suggests the bulk of the Slew Survey sources are drawn from one or more transient populations. We report revised X-ray positions for the XRT-detected sources, with typical uncertainties of 2.9", reducing the number of catalogued optical matches to just a single source in most cases. We characterise the sources detected by Swift through their X-ray spectra and variability and via UVOT photometry and catalogued nIR, optical and radio observations. Six sources can be associated with known objects and 8 may be associated with unidentified ROSAT sources within the 3-sigma error radii of our revised X-ray positions. We find 10 of the 30 XRT-detected sources are clearly stellar in nature, including one periodic variable star and 2 high proper motion stars. For 11 sources we propose an AGN classification, among which 4 are detected with BAT and 3 have redshifts spanning z = 0.2 - 0.9 obtained from the literature or from optical spectroscopy presented here. The 67 Slew Survey sources we do not detect with Swift are studied via their characteristics in the Slew Survey and by comparison with the XRT and BAT detected population. We suggest that these are mostly if not all extragalactic, though unlikely to be highly absorbed sources in the X-rays such as Compton thick AGN. A large number of these are highly variable soft X-ray sources. A small fraction of mainly hard-band detections may be spurious. This follow-up programme brings us a step further to completing the identifications of a substantial sample of XMM-Newton Slew Survey sources, important for understanding the nature of the transient sky and allowing flux-limited samples to be constructed.Comment: 19 pages, 7 figures. Accepted for publication in MNRA
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