This paper investigates a poorly studied open cluster, NGC 5288, using 2MASS JHKS and the recently released Gaia DR3 astrometric and photometric data. The mean proper motions in right ascension and ...declination are estimated as (-3.840 ± 0.230) and (-1.934 ± 0.162) mas yr-1 respectively. We also derive the age and distance of the cluster as 510 ± 190 Myr and 2.64 ± 0.11 kpc, using color-magnitude diagrams (CMDs). We also obtain the distance as 2.77 ± 0.42 kpc using the parallax method. Interstellar reddening E(B ‒ V) in the direction of the cluster is determined as 0.45 mag using the ((J ‒ H), (J ‒ K)) color-color diagram. We find the mass function slope for main-sequence stars as 1.39 ± 0.29 within the mass range 1.0-2.7 M☉, which agrees with Salpeter's value within the uncertainty. Galactic orbits are derived using the Galactic potential model, indicating that NGC 5288 follows a circular path around the Galactic center.
ABSTRACT
A gold standard for the study of M dwarfs is the eclipsing binary CM Draconis. It is rare because it is bright (Jmag = 8.5) and contains twin fully convective stars on an almost perfectly ...edge-on orbit. Both masses and radii were previously measured to better than 1 per cent precision, amongst the best known. We use 15 sectors of data from the Transiting Exoplanet Survey Satellite (TESS) to show that CM Draconis is the gift that keeps on giving. Our paper has three main components. First, we present updated parameters, with radii and masses constrained to previously unheard-of precisions of ≈0.06 and ≈0.12 per cent, respectively. Secondly, we discover strong and variable spot modulation, suggestive of spot clustering and an activity cycle of the order of ≈4 yr. Thirdly, we discover 163 flares. We find a relationship between the spot modulation and flare rate, with flares more likely to occur when the stars appear brighter. This may be due to a positive correlation between flares and the occurrence of bright spots (plages). The flare rate is surprisingly not reduced during eclipse, but one flare may show evidence of being occulted. We suggest that the flares may be preferentially polar, which has positive implications for the habitability of planets orbiting M dwarfs.
Endodontic treatment of Radix Entomolaris is challenging and requires a complete understanding of root canal system, and skills to manage the commonly occurring mishaps during the treatment. ...Therefore, comprehensive clinical & radiographic interpretation is critical in identifying unusual root canal morphologies. The additional root variation in the mandibular molars may be present either mesio-bucally (Radix Paramolaris) or distolingually (Radix Entomolaris). This case series intends to discuss the diagnosis, endodontic challenges during file separation, and non-surgical endodontic management of two cases of Radix Entomolaris in the mandibular first molar.
This paper examines the interplay between desegregation, institutional bias, and individual behavior in education. Using a game-theoretic model that considers race-heterogeneous social incentives, ...the study investigates the effects of between-school desegregation on within-school disparities in coursework. The analysis incorporates a segregation measure based on entropy and proposes an optimization-based approach to evaluate the impact of student reassignment policies. The results highlight that Black and Hispanic students in predominantly White schools, despite receiving less encouragement to apply to college, exhibit higher enrollment in college-prep coursework due to stronger social incentives from their classmates' coursework decisions.
ABSTRACT
M-dwarfs are the most abundant stars in the galaxy and popular targets for exoplanet searches. However, their intrinsic faintness and complex spectra inhibit precise characterization. We ...only know of dozens of M-dwarfs with fundamental parameters of mass, radius, and effective temperature characterized to better than a few per cent. Eclipsing binaries remain the most robust means of stellar characterization. Here we present two targets from the Eclipsing Binary Low Mass (EBLM) survey that were observed with K2: EBLM J0055-00 and EBLM J2217-04. Combined with HARPS and CORALIE spectroscopy, we measure M-dwarf masses with precisions better than 5 per cent, radii better than 3 per cent, and effective temperatures on order 1 per cent. However, our fits require invoking a model to derive parameters for the primary star and fitting the M-dwarf using the transit and radial velocity observations. By investigating three popular stellar models, we determine that the model uncertainty in the primary star is of similar magnitude to the statistical uncertainty in the model fits of the secondary M-dwarf. Therefore, whilst these can be considered benchmark M-dwarfs, we caution the community to consider model uncertainty when pushing the limits of precise stellar characterization.
Immunoglobulin-like (Ig) domains are a widely expanded superfamily that act as interaction motifs or as structural spacers in multidomain proteins. Vertebrate filamins (FLNs), which are ...multifunctional actin-binding proteins, consist of 24 Ig domains. We have recently discovered that in the C-terminal rod 2 region of FLN, Ig domains interact with each other forming functional domain pairs, where the interaction with signaling and transmembrane proteins is mechanically regulated by weak actomyosin contraction forces. Here, we investigated if there are similar inter-domain interactions around domain 4 in the N-terminal rod 1 region of FLN. Protein crystal structures revealed a new type of domain organization between domains 3, 4, and 5. In this module, domains 4 and 5 interact rather tightly, whereas domain 3 has a partially flexible interface with domain 4. NMR peptide titration experiments showed that within the three-domain module, domain 4 is capable for interaction with a peptide derived from platelet glycoprotein Ib. Crystal structures of FLN domains 4 and 5 in complex with the peptide revealed a typical β sheet augmentation interaction observed for many FLN ligands. Domain 5 was found to stabilize domain 4, and this could provide a mechanism for the regulation of domain 4 interactions.
Background: Filamins are actin cross-linking and signaling scaffolding proteins where C-terminal domains have inter-domain interactions but little is known about the N-terminal domains.
Results: Crystal structures of N-terminal domains 3–5 reveal novel domain packing and interaction details of domain 4.
Conclusion: Domain 4 is stabilized by interaction with domain 5.
Significance: Here, inter-domain interactions positively regulate domain 4 interactions with ligands.
Stellar binaries are ubiquitous in the galaxy and a laboratory for astrophysical effects. We use TESS to study photometric modulations in the lightcurves of 162 unequal mass eclipsing binaries from ...the EBLM (Eclipsing Binary Low Mass) survey, comprising F/G/K primaries and M-dwarf secondaries. We detect modulations on 81 eclipsing binaries. We catalog the rotation rates of the primary star in 69 binaries and discover 17 ellipsoidal variables. In a large portion (at least \(\sim 51\%\)) of our sample, we detect photometric modulations consistent with two over-densities of spots on the primary star that are roughly \(180^{\circ}\) apart. We show that these so-called active longitudes are preferentially at the sub- and anti-stellar points on the primary star. Physically, this means that the spots on the primary star preferentially face directly towards and away from the secondary star.
Filamins regulate the actin cytoskeleton by cross-linking actin filaments, linking the cytoskeleton to the cell membrane, and through interaction with numerous binding partners such as intracellular ...signalling molecules, ion channels, receptors, enzymes and transcription factors. The rod region of filamins consists of 24 immunoglubulin (Ig)-like repeats, for some of which the functional unit is a domain pair. Our aim is to study filamin Ig domain-domain interactions and quaternary arrangement as well as to locate peptide binding sites on domain assemblies. We report here the H(N), N(H), C(α), C(β), and methyl group assignments of filamin A three-domain fragment IgFLNa3-5 and filamin C two-domain fragment IgFLNc4-5.
Filamins regulate the actin cytoskeleton by cross-linking actin filaments, linking the cytoskeleton to the cell membrane, and through interaction with numerous binding partners such as intracellular ...signalling molecules, ion channels, receptors, enzymes and transcription factors. The rod region of filamins consists of 24 immunoglubulin (Ig)-like repeats, for some of which the functional unit is a domain pair. Our aim is to study filamin Ig domain–domain interactions and quaternary arrangement as well as to locate peptide binding sites on domain assemblies. We report here the H
N
, N
H
, C
α
, C
β
, and methyl group assignments of filamin A three-domain fragment IgFLNa3–5 and filamin C two-domain fragment IgFLNc4–5.
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