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Age is a stellar parameter that is both fundamental and difficult to determine. Among middle-aged M dwarfs, the most prolific hosts of close-in and detectable exoplanets, gyrochronology is the most promising method to assign ages, but requires calibration by rotation-temperature sequences (gyrochrones) in clusters of known ages. We curated a catalog of 249 late K- and M-type (($T_{eff}$=3200-4200K) exoplanet host stars with established rotation periods, and applied empirical, temperature-dependent rotation-age relations based on relevant published gyrochrones, including one derived from observations of the 4 Gyr-old open cluster M67. We estimated ages for 227 of these stars, and upper limits for 8 others, excluding 14 which have too rapidly rotating or are otherwise outside the valid parameter range of our gyrochronology. We estimated uncertainties based on observed scatter in rotation periods in young clusters, error in the gyrochrones, and uncertainties in temperature and non-solar metallicity. For those stars with measured metallicities, we provide but do not incorporate a correction for the effects of deviation from solar metallicity. The age distribution of our sample declines to near zero at 10 Gyr, the age of the Galactic disk, with the handful of outliers explainable by large uncertainties. Continued addition or extension of cluster rotation sequences to more thoroughly calibrate the gyrochronology in time and temperature space, more precise and robust measurement of rotation periods, and more accurate stellar parameter measurements will enable continued improvements in the age estimates of these important exoplanet host stars., accepted to MNRAS. Full Table 1 in CDS machine-readable format included as ancillary file time_table.mrt more...

Background: The loss of alveolar bone support is the main symptoms of the destructive periodontal disease. Periodontitis leads to formation of the interbony defects. For resolution of the infection, the elimination of IBD is highly needed. For the filing of the IBD and regeneration of the bone in the periodontal therapy, different bone grafts are used. Objective: The study aimed to evaluate the efficacy of calcium phosphate composite bone graft in patients suffering from periodontal intrabony problems. Study Design: It is a randomized and interventional study conducted at Multan Medical & Dental College, Multan and DOW University of Health Sciences, Karachi for the duration of six months from December 2021 to May 2022. Material and Methods: The study was conducted on 16 patients that fulfilled the inclusion criteria. All the patients completed the follow-up. The radiographic parameters were also evaluated. The baseline data from six months and three months was analyzed and data was plotted. Results: It was found that the primary closure was carried out for all the patients. There was no statistical significance found between the groups related to depth of the defect and the walls number groups before operation. There was a prominent reduction in plague concentration and gingival index. In case of test group there was a greater statistical reduction in the test group as compared to the control. The recession of gingival parameter was seen in both the groups. There was no statistical difference observed here. Conclusion This study helps to provide significant results and evidence that the easy graft crystal can be used for the treatment of periodontal intrabony issues. Keywords: Intrabony defects and calcium phosphate composite bone graft. more...

We report on the properties of eclipsing binaries from the Kepler mission with a newly developed photometric modeling code, which uses the light curve, spectral energy distribution of each binary, and stellar evolution models to infer stellar masses without the need for radial velocity measurements. We present solutions and posteriors to orbital and stellar parameters for 728 systems, forming the largest homogeneous catalogue of full Kepler binary parameter estimates to date. Using comparisons to published radial velocity measurements, we demonstrate that the inferred properties (e.g., masses) are reliable for well-detached main-sequence binaries, which make up the majority of our sample. The fidelity of our inferred parameters degrades for a subset of systems not well described by input isochrones, such as short-period binaries that have undergone interactions, or binaries with post-main sequence components. Additionally, we identify 35 new systems which show evidence of eclipse timing variations, perhaps from apsidal motion due to binary tides or tertiary companions. We plan to subsequently use these models to search for and constrain the presence of circumbinary planets in Kepler eclipsing binary systems., Comment: 36 pages, 16 figures; accepted 2019 July 30 to MNRAS more...

Spectroscopic Eclipsing Binaries (SEBs) are fundamental benchmarks in stellar astrophysics and today are observed in breathtaking detail by missions like TESS, Kepler, and APOGEE. We develop a methodology for simultaneous analysis of high precision Kepler light curves and high resolution near-IR spectra from APOGEE and present orbital solutions and evolutionary histories for a subset of SEBs within this overlap. Radial velocities extracted from APOGEE spectra using the Broadening Function technique are combined with Kepler light curves and to yield binary orbital solutions. The Broadening Function approach yields more precise radial velocities than the standard Cross-Correlation Function, which in turn yields more precise orbital parameters and enables the identification of tertiary stars. The orbital periods of these seven SEBs range from 4 to 40 days. Four of the systems (KIC 5285607, KIC 6864859, KIC 6778289, and KIC 4285087) are well-detached binaries. The remaining three systems have apparent tertiary companions, but each exhibits two eclipses along with at least one spectroscopically varying component (KIC 6449358, KIC 6131659, and KIC 6781535). Gaia distances are available for four targets which we use to estimate temperatures of both members of these SEBs. We explore evolutionary histories in H-R diagram space and estimate ages for this subset of our sample. Finally, we consider the implications for the formation pathways of close binary systems via interactions with tertiary companions. Our methodology combined with the era of big data and observation overlap opens up the possibility of discovering and analyzing large numbers of diverse SEBs, including those with high flux ratios and those in triple systems., 25 pages, 23 figures, 4 tables, accepted for publication in AJ more...