6,915 research outputs found

    KIC 9821622: An interesting lithium-rich giant in the Kepler field

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    We report the discovery of a new exceptional young lithium-rich giant, KIC 9821622, in the \textit{Kepler} field that exhibits an unusually large enhancement of α\alpha, Fe-peak, and \textit{r}-process elements. From high-resolution spectra obtained with GRACES at Gemini North, we derived fundamental parameters and detailed chemical abundances of 23 elements from equivalent widths and synthesis analysis. By combining atmospheric stellar parameters with available asteroseismic data, we obtained the stellar mass, radius, and age. The data analysis reveals that KIC 9821622 is a Li-rich (A(Li)NLTE_{NLTE} = 1.80 ±\pm 0.2) intermediate-mass giant star (MM = 1.64 M⊙M_{\odot}) located at the red giant branch near the luminosity bump. We find unexpectedly elevated abundances of Fe-peak and \textit{r}-process elements. In addition, as previously reported, we find that this is a young star (2.37 Gyr) with unusually high abundances of α\alpha-elements ([α\alpha/Fe] = 0.31). The evolutionary status of KIC 9821622 suggests that its Li-rich nature is the result of internal fresh Li that is synthesized through the Cameron-Fowler mechanism near the luminosity bump. However, its peculiar enhancement of α\alpha, Fe-peak, and \textit{r}-process elements opens the possibility of external contamination by material enriched by a supernova explosion. Although it is less likely, planet accretion cannot be ruled out.Comment: Letter, 6 pages, 3 figures, Accepted for publication in A&A. - Some language editing include

    A multi-flow model for microquasars

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    We present a new picture for the central regions of Black Hole X-ray Binaries. In our view, these central regions have a multi-flow configuration which consists in (1) an outer standard accretion disc down to a transition radius r_J, (2) an inner magnetized accretion disc below r_J driving (3) a non relativistic self-collimated electron-proton jet surrounding, when adequate conditions for pair creation are met, (4) a ultra relativistic electron-positron beam. This accretion-ejection paradigm provides a simple explanation to the canonical spectral states, from radio to X/gamma-rays, by varying the transition radius r_J and disc accretion rate independently. Large values of r_J and low accretion rate correspond to Quiescent and Hard states. These states are characterized by the presence of a steady electron-proton MHD jet emitted by the disc below r_J. The hard X-ray component is expect to form at the jet basis. When r_J becomes smaller than the marginally stable orbit r_i, the whole disc resembles a standard accretion disc with no jet, characteristic of the Soft state. Intermediate states correspond to situations where r_J ~ r_i. At large accretion rate, an unsteady pair cascade process is triggered within the jet axis, giving birth to flares and ejection of relativistic pair blobs. This would correspond to the luminous intermediate state, with its associated superluminal motions.Comment: 12 pages, 3 figures. Proceedings of ``High Energies in the Highlands'', Fort-William, 27 June-1 July 200

    The Effect of Two States of Hydration on Muscular Endurance in Men

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    The purpose of this study was to investigate the effects of two states of hydration has an effect on muscular endurance in men. Two groups of four men randomly assigned to each group participated in both states of hydration. Both groups were tested at baseline for height, weight, intra- and extra-cellular water, total body water, and a one-repetition maximum strength test. Subjects were then tested after a 24 hour period of water deprivation, and after a 24 hour period of normal water intake (8 ten oz glasses of water). A urine specific gravity test, intra- and extra-cellular water, total body water, and weight were used to determine hydration. A maximum repetition test at 50 percent of the subjects 1RM was used to determine muscle endurance. Results showed that there was no statistical significance (p\u3c.05) between hydration and muscular endurance at a decrease of one percent total body weight. It was concluded that while in the literature it may appear that there may be a relationship between hydration and performance, there was no statistical difference between the two states of hydration in this experiment

    BeppoSAX observations of the quasar Markarian 205

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    We present the first BeppoSAX observation (0.1 to 220 keV) of the quasar Mrk 205. We have searched for the unusual Fe line profile claimed in the XMM-Newton spectrum which has been widely discussed in recent literature. We find no evidence for a broad, ionized Fe line component in our data. We detect for the first time a Compton hump in this object. Besides, when this component is included in the fit, the line strength diminishes, in agreement with a recent re-analysis of the XMM-Newton data, but with better constraints on the reflection component thanks to the PDS instrument (15-220 keV). We interpret this fact as another indication for illumination of a distant and cold material rather than reprocessing in the highly ionized inner parts of an accretion disk. We cannot constrain the presence of a high energy cutoff but we confirm the existence of a variable soft excess (one year timescale).Comment: 13 pages, 12 figures, accepted for publication in A&

    The XMM/BeppoSAX observation of Mkn 841

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    Mkn 841 has been observed simultaneously by XMM and BeppoSAX in January 2001. Due to operational contingency, the 30ks XMM observation was split into two parts, separated by about 15 hours. We first report the presence of a narrow iron line which appears to be rapidly variable between the two pointings, requiring a non-standard interpretation. We then focus on the analysis of the broad band (0.3-200 keV) continuum using the XMM/EPIC, RGS and SAX/PDS data. The Mkn 841 spectrum is well fitted by a comptonization model in a geometry more photon-fed than a simple slab geometry above a passive disk. It presents a relatively large reflection (R>2) which does not agree with an apparently weak iron line. It also show the presence of a strong soft excess wellfitted by a comptonized spectrum in a cool plasma, suggesting the presence of a multi-temperature corona.Comment: 4 pages, 5 figures. Proc. of the meeting: "The Restless High-Energy Universe" (Amsterdam, The Netherlands), E.P.J. van den Heuvel, J.J.M. in 't Zand, and R.A.M.J. Wijers Ed

    Effect of Ferric Sodium EDTA administration, in combination with vitamin C, folic acid, copper gluconate, zinc gluconate and selenomethionine, on cardiovascular risk evaluation: exploration of the HRV frequency domain

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    diseases. Using the Heart Rate Variability (HRV) analysis is possible to provide an evaluation of the safety and the effectiveness of intervention. Objective: To evaluate the efficacy and safety of Ferric Sodium EDTA in combination with vitamin C, folic acid, copper gluconate, zinc gluconate and selenomethionine (Ferachel forte®) 2 tabs/day for 24 days in elderly patients with secondary anaemia, by exploring the HRV frequency domain. Methods: In 45 elderly patients with secondary anaemia and/or low-moderate kidney failure, laboratory values after administration of Ferric Sodium EDTA, 2 tabs a day, in combination with vitamin C, folic acid, copper gluconate, zinc gluconate and selenomethionine (Ferachel forte®) for 24 days (N=16 patients) or ferrous gluconate 63 mg/day added to saline solution, administered using intravenous access during the hospitalization period of 15 ± 5 days (N=29 patients) were evaluated. Also, ECG signals and bioelectrical impedance (BIA) were measured. Results: Oral iron supplementation with Ferric Sodium EDTA, in combination with vitamin C, folic acid, copper gluconate, zinc gluconate and selenomethionine (Ferachel forte®) confirmed to be effective and safe about the cardiovascular risk in old patients. This study showed the real superiority of the oral administration about the cardiovascular risk in elderly patients in comparison with intravenous administration of ferrous gluconate. Conclusion: This study confirms that Ferric Sodium EDTA combination (Ferachel forte®) can be a valid alternative to ferrous gluconate intravenous therapy (gold standard) in the treatment of secondary anaemia in elderly patients. In fact, during the treatment, efficacy results have been maintained without statistically significant variations about cardiovascular risk, evaluated by exploring the HRV frequency domain
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