5,439 research outputs found

    Three Li-rich K giants: IRAS 12327-6523, IRAS 13539-4153, and IRAS 17596-3952

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    We report on spectroscopic analyses of three K giants previously suggested to be Li-rich: IRAS 12327-6523, IRAS 13539-4153, and IRAS 17596-3952. High-resolution optical spectra and the LTE model atmospheres are used to derive the stellar parameters: (TeffT_{\rm eff}, log gg, [Fe/H]), elemental abundances, and the isotopic ratio 12^{12}C/13^{13}C. IRAS 13539-4153 shows an extremely high Li abundance of logâĄÏ”\log\epsilon(Li) ≈\approx 4.2, a value ten times more than the present Li abundance in the local interstellar medium. This is the third highest Li abundance yet reported for a K giant. IRAS 12327-6523 shows a Li abundances of logâĄÏ”\log\epsilon(Li)≈\approx 1.4. IRAS 17596-3952 is a rapidly rotating (Vsin⁥iV{\sin i} ≈\approx 35 km s−1^{-1}) K giant with logâĄÏ”\log\epsilon(Li) ≈\approx 2.2. Infrared photometry which shows the presence of an IR excess suggesting mass-loss. A comparison is made between these three stars and previously recognized Li-rich giants.Comment: 17 pages, 6 figures, accepted for A

    The Theory of the Interleaving Distance on Multidimensional Persistence Modules

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    In 2009, Chazal et al. introduced Ï”\epsilon-interleavings of persistence modules. Ï”\epsilon-interleavings induce a pseudometric dId_I on (isomorphism classes of) persistence modules, the interleaving distance. The definitions of Ï”\epsilon-interleavings and dId_I generalize readily to multidimensional persistence modules. In this paper, we develop the theory of multidimensional interleavings, with a view towards applications to topological data analysis. We present four main results. First, we show that on 1-D persistence modules, dId_I is equal to the bottleneck distance dBd_B. This result, which first appeared in an earlier preprint of this paper, has since appeared in several other places, and is now known as the isometry theorem. Second, we present a characterization of the Ï”\epsilon-interleaving relation on multidimensional persistence modules. This expresses transparently the sense in which two Ï”\epsilon-interleaved modules are algebraically similar. Third, using this characterization, we show that when we define our persistence modules over a prime field, dId_I satisfies a universality property. This universality result is the central result of the paper. It says that dId_I satisfies a stability property generalizing one which dBd_B is known to satisfy, and that in addition, if dd is any other pseudometric on multidimensional persistence modules satisfying the same stability property, then d≀dId\leq d_I. We also show that a variant of this universality result holds for dBd_B, over arbitrary fields. Finally, we show that dId_I restricts to a metric on isomorphism classes of finitely presented multidimensional persistence modules.Comment: Major revision; exposition improved throughout. To appear in Foundations of Computational Mathematics. 36 page

    Congenital thumb anomalies and the consequences for daily life : patients’ long-term experience after corrective surgery. A qualitative study

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    Purpose: The aim of the study was to explore patients’ long-term experience of a congenital hand problem, and the consequences for daily life. Method: Fifteen participants with a median age 24 years (17–55 years), born with thumb hypoplasia/aplasia or thumb duplication were interviewed using a semi-structured interview guide. The interviews were subjected to qualitative content analysis. Results: Although the mobility and strength in the thumb/hand(s) varied within the group, hand function was generally described as good. Compensatory strategies were used to overcome practical obstacles. The emotional reactions to being visibly different from peers in early life varied from total acceptance and a sense of pride in being special, to deep distress and social withdrawal. Support from parents, teachers and others was important in facing emotional challenges and practical consequences. Conclusion: The present study highlights the importance of healthcare professionals addressing appearance-related concerns which may have long-term emotional and social consequences for patients born with a thumb anomaly. Implications for RehabilitationAppearance-related concerns and need for emotional support should be fully considered throughout the rehabilitation process to prevent distress and social withdrawal.Effective problem-solving strategies, such as compensation, change in occupational performance and support from others may reduce activity limitations and participation restriction

    Sound radiation and sound insulation performances of maritime bulkheads

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    The research of materials matching low weight and high resistance has always been a key factor in the shipbuilding industry to increase performances and loading capacity. Nowadays, other issues add up to economical convenience, and building quiet ships is important not only for passengers and cabin crew, but also to make harbor areas more comfortable and to respect the aquatic environment. In this context, using sandwich or composite materials must be carefully evaluated and the sound insulation performances must be considered throughout all stages of the design process. This work presents some evaluations about the sound insulation performances of a ribbed fiberglass bulkhead and of a balsa-core sandwich bulkhead. In particular, the bending stiffness and the sound transmission loss obtained by sound transmission suites and mobility measurements are provided. From such measurements it has also been possible to determine the radiation efficiency of the structures, whose optimization is particularly important when a reduction of the noise pollution is required

    Ab initio Ti-Zr-Ni phase diagram predicts stability of icosahedral TiZrNi quasicrystals

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    The ab initio phase diagram determines the energetic stability of the icosahedral TiZrNi quasicrystal. The complete ab initio zero-temperature ternary phase diagram is constructed from the calculated energies of the elemental, binary and ternary Ti-Zr-Ni phases. For this, the icosahedral i-TiZrNi quasicrystal is approximated by periodic structures of up to 123 atoms/unit cell, based on a decorated-tiling model [R. G. Hennig, K. F. Kelton, A. E. Carlsson, and C. L. Henley, Phys. Rev. B 67, 134202 (2003)]. The approximant structures containing the 45-atom Bergman cluster are nearly degenerate in energy, and are all energetically stable against the competing phases. It is concluded that i-TiZrNi is a ground-state quasicrystal, as it is experimentally the low-temperature phase for its composition

    Bioclipse-R: integrating management and visualization of life science data with statistical analysis

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    SUMMARY: Bioclipse, a graphical workbench for the life sciences, provides functionality for managing and visualizing life science data. We introduce Bioclipse-R, which integrates Bioclipse and the statistical programming language R. The synergy between Bioclipse and R is demonstrated by the construction of a decision support system for anticancer drug screening and mutagenicity prediction, which shows how Bioclipse-R can be used to perform complex tasks from within a single software system. Availability and implementation: Bioclipse-R is implemented as a set of Java plug-ins for Bioclipse based on the R-package rj. Source code and binary packages are available from https://github.com/bioclipse and http://www.bioclipse.net/bioclipse-r, respectively. CONTACT: [email protected] SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online
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