Seismic analysis of 70 Ophiuchi A: A new quantity proposed

The basic intent of this paper is to model 70 Ophiuchi A using the latest asteroseismic observations as complementary constraints and to determine the fundamental parameters of the star. Additionally, we propose a new quantity to lift the degeneracy between the initial chemical composition and stellar age. Using the Yale stellar evolution code (YREC7), we construct a series of stellar evolutionary tracks for the mass range $M$ = 0.85 -- 0.93 $M_{\odot}$ with different composition $Y_{i}$ (0.26 -- 0.30) and $Z_{i}$ (0.017 -- 0.023). Along these tracks, we select a grid of stellar model candidates that fall within the error box in the HR diagram to calculate the theoretical frequencies, the large- and small- frequency separations using the Guenther's stellar pulsation code. Following the asymptotic formula of stellar $p$-modes, we define a quantity $r_{01}$ which is correlated with stellar age. Also, we test it by theoretical adiabatic frequencies of many models. Many detailed models of 70 Ophiuchi A have been listed in Table 3. By combining all non-asteroseismic observations available for 70 Ophiuchi A with these seismological data, we think that Model 60, Model 125 and Model 126, listed in Table 3, are the optimum models presently. Meanwhile, we predict that the radius of this star is about 0.860 -- 0.865 $R_{\odot}$ and the age is about 6.8 -- 7.0 Gyr with mass 0.89 -- 0.90 $M_{\odot}$. Additionally, we prove that the new quantity $r_{01}$ can be a useful indicator of stellar age.Comment: 23 pages, 5 figures, accepted by New Astronom

Asteroseismic study of solar-like stars: A method of estimating stellar age

Asteroseismology, as a tool to use the indirect information contained in stellar oscillations to probe the stellar interiors, is an active field of research presently. Stellar age, as a fundamental property of star apart from its mass, is most difficult to estimate. In addition, the estimating of stellar age can provide the chance to study the time evolution of astronomical phenomena. In our poster, we summarize our previous work and further present a method to determine age of low-mass main-sequence star.Comment: 2 pages, 1 figures, submitted to IAUS25

Portable Perimetry Using Eye-Tracking on a Tablet Computer—A Feasibility Assessment

Purpose: Visual field (VF) examination by standard automated perimetry (SAP) is an important method of clinical assessment. However, the complexity of the test, and its use of bulky, expensive equipment makes it impractical for case-finding. We propose and evaluate a new approach to paracentral VF assessment that combines an inexpensive eye-tracker with a portable tablet computer (“Eyecatcher”). Methods: Twenty-four eyes from 12 glaucoma patients, and 12 eyes from six age-similar controls were examined. Participants were tested monocularly (once per eye), with both the novel Eyecatcher test and traditional SAP (HFA SITA standard 24-2). For Eyecatcher, the participant's task was to simply to look at a sequence of fixed-luminance dots, presented relative to the current point of fixation. Start and end fixations were used to determine locations where stimuli were seen/unseen, and to build a continuous map of sensitivity loss across a VF of approximately 20°. Results: Eyecatcher was able to clearly separate patients from controls, and the results were consistent with those from traditional SAP. In particular, mean Eyecatcher scores were strongly correlated with mean deviation scores (r2 = 0.64, P < 0.001), and there was good concordance between corresponding VF locations (∼84%). Participants reported that Eyecatcher was more enjoyable, easier to perform, and less tiring than SAP (all P < 0.001). Conclusions: Portable perimetry using an inexpensive eye-tracker and a tablet computer is feasible, although possible means of improvement are suggested. Translational Relevance: Such a test could have significant utility as a case finding device

Reversible dynamic isomerism change in the solid state, from Bi4I16 clusters to BiI4 1D chains in L-cystine based hybrids: templating effect of cations in iodobismuthate network formation

The dehydration of a iodobismuthate hybrid built up from Bi4I16 clusters and protonated L-cystine molecules involves an unprecedented reversible dynamic structural change in the solid state leading to 1D BiI4 chains and 1D helical molecular chains, highlighting the templating effect of cations in the formation of iodobismuthate network

Structural diversity and retro-crystal engineering analysis of iodometalate hybrids

With guidance from retro-crystal engineering, iodometalate structures based on MI6 octahedra of group 14 (M = Sn(II), Pb(II)) and group 15 (M = Sb(III) and Bi(III)) are analysed. The criterion of I/M ratio, with the function of indicating the degree of condensation of octahedra in inorganic networks and the average charge density at the organic–inorganic interface, is introduced to classify all of the iodometalate networks, resulting in an easy and clear way to identify isomers with different dimensionalities. Of all iodometalates, the 2D M(II)I4 anion derived from the perovskite network is special since it can be easily stabilized by a range of common organic cations. We provide here the up-to-date progress in this extensively studied field, focusing on crystal engineering of hybrids in the aim of getting materials with a reduced band gap. Relationships between the molecular layouts of cationic entities and the structures of several non-perovskite anionic networks, focusing on the organic–inorganic interface, are highlighted. Distinct dependences between different types of cations and different types of anions are revealed, although it is still unfeasible to apply them in the actual control, design, or prediction of specific hybrid structures

The Complete One-Loop Dilation Operator of N=2 SuperConformal QCD

We evaluate the full planar one-loop dilation operator of N=2 SuperConformal QCD, the SU(N_c) super Yang-Mills theory with N_f = 2 N_c fundamental hypermultiplets, in the flavor-singlet sector. Remarkably, the spin-chain Hamiltonian turns out to be completely fixed by superconformal symmetry, as in N=4 SYM. We present a more general calculation, for the superconformal quiver theory with SU(N_c)X SU(N_c) gauge group, which interpolates between N=2 SCQCD and the Z_2 orbifold of N=4 SYM; here symmetry fixes the Hamiltonian up to a single parameter, corresponding to the ratio of the two marginal gauge couplings.Comment: v2: typo corrected, cosmetic changes. JHEP versio

Nouveau découpage de la zone de forêt dense humide de la Côte d’Ivoire

Les cartes de la végétation connues sur la Côte d’Ivoire sont essentiellement basées sur la physionomie de la végétation. Dans le présent travail, nous sommes partis d’une base de données floristiques récapitulant toutes les informations botaniques disponibles sur la Côte d’Ivoire, de 1882 à 2006, et riche de 46.646 saisies relatives aux taxons végétaux vasculaires de la zone de forêt dense humide ivoirienne pour établir un découpage de ladite zone. L’intégration de ces taxons et les paramètres éco-géographiques dans une analyse canonique de correspondance nous a permis d’identifier cinq principaux faciès de forêt dense humide dont quatre sont de basses altitudes. Le déterminisme de ces principaux faciès est soit géologique, soit pédologique, soit climatique, soit à la fois pédoclimatiques.Mots clé : zone de forêt de dense, principaux faciès, déterminisme, Côte d’Ivoir

Where there’s ‘willingness’ there’s a way: barriers and facilitators to maternal, newborn and child health data sharing by the private health sector in Uttar Pradesh, India

In India and Uttar Pradesh (UP), the private health sector plays an important role in health care services, including institutional deliveries, but there is limited information on the availability of maternal, newborn and child health (MNCH) data that private facilities maintain and share with the public health information system. Sharing data could help the public sector plan their resources more efficiently. Aim of the study: To explore current practices of MNCH data availability and sharing/reporting by private health facilities and the barriers and facilitators to data sharing