The Comprehensive Antibiotic Resistance Database (CARD; https://card.mcmaster.ca) is a curated resource providing reference DNA and protein sequences, detection models and bioinformatics tools on the molecular basis of bacterial antimicrobial resistance (AMR). CARD focuses on providing high-quality reference data and molecular sequences within a controlled vocabulary, the Antibiotic Resistance Ontology (ARO), designed by the CARD biocuration team to integrate with software development efforts for resistome analysis and prediction, such as CARD’s Resistance Gene Identifier (RGI) software. Since 2017, CARD has expanded through extensive curation of reference sequences, revision of the ontological structure, curation of over 500 new AMR detection models, development of a new classification paradigm and expansion of analytical tools. Most notably, a new Resistomes & Variants module provides analysis and statistical summary of in silico predicted resistance variants from 82 pathogens and over 100 000 genomes. By adding these resistance variants to CARD, we are able to summarize predicted resistance using the information included in CARD, identify trends in AMR mobility and determine previously undescribed and novel resistance variants. Here, we describe updates and recent expansions to CARD and its biocuration process, including new resources for community biocuration of AMR molecular reference data.
The B[e] phenomenon is defined as the simultaneous presence of low-excitation forbidden line emission and strong infrared excess in the spectra of early-type stars. It was discovered in our Galaxy 30 years ago in the course of the early exploration of the infrared sky and initially identified in 65 Galactic objects, of which nearly half remained unclassified. The phenomenon is associated with objects at different evolutionary stages, ranging from the preYmainsequence to the planetary nebula stage. We review the studies of both the original 65 and subsequently identified Galactic stars with the B[e] phenomenon. A new classification is proposed for stars with the B[e] phenomenon based on the time of dust formation in their environments. Properties of the unclassified Galactic B[e] stars are analyzed. We propose that these objects are binary systems that are currently undergoing or have recently undergone a phase of rapid mass exchange, associated with a strong mass loss and dust formation. A new name, FS CMa stars, and classification criteria are proposed for the unclassified B[e] stars.
We present the results of recent multicolor photometric and high-resolution spectroscopic observations of the bright Be star Aqr. Observational data collected from the literature were used to study the star's variations over the last four decades. The star is identified with the IR sources F22227+0107 in the IRAS Faint Point Source Catalog and MSX5 G066.0066À44.7392 in the MSX Catalog. The variations in near-IR brightness of Aqr are found to be among the largest reported for Be stars. Since 1996, the star has shown only weak signs of circumstellar emission, which has allowed us to refine the fundamental stellar parameters: A V ¼ 0:15 mag, T eff ¼ 24;000 K, log g ¼ 3:9, and M V ¼ À2:95 mag. A weak emission component of the H line has been detected during the recent quasi-normal star phase. From analysis of the H line profiles, we find antiphased radial velocity variations of the emission component and the photospheric absorption, with a period of 84.1 days and semiamplitudes of 101.4 and 16.7 km s À1 , respectively. This result suggests that Aqr may be a binary system consisting of stars with masses of M 1 sin 3 i ¼ 12:4 M , M 2 sin 3 i ¼ 2:0 M . We also estimate the orbital inclination angle to be between 50 and 75 . We suggest that the photometric, spectroscopic, and polarimetric variations observed during the second half of the 20th century may be due to variable mass transfer between the binary components.
Context. Circumstellar disks and outflows play a fundamental role in star formation. Infrared spectro-interferometry allows the inner accretion-ejection region to be resolved. Aims. We study the disk and Brγ-emitting region of MWC 297 with high spatial and spectral resolution and compare our observations with disk-wind models. Methods. We measured interferometric visibilities, wavelength-differential phases, and closure phases of MWC 297 with a spectral resolution of 12 000. To interpret our MWC 297 observations, we employed disk-wind models. Results. The measured continuum visibilities confirm previous results that the continuum-emitting region of MWC 297 is remarkably compact. We derive a continuum ring-fit radius of ∼2.2 mas (∼0.56 AU at a distance of 250 pc), which is ∼5.4 times smaller than the 3 AU dust sublimation radius expected for silicate grains (in the absence of radiation-shielding material). The strongly wavelengthdependent and asymmetric Brγ-emitting region is more extended (∼2.7 times) than the continuum-emitting region. At the center of the Brγ line, we derive a Gaussian fit radius of ∼6.3 mas HWHM (∼1.6 AU). To interpret the observations, we employ a magnetocentrifugally driven disk-wind model consisting of an accretion disk, which emits the observed continuum radiation, and a disk wind, which emits the Brγ line. The calculated wavelength-dependent model intensity distributions and Brγ line profiles are compared with the observations (i.e., K-band spectrum, visibilities, differential phases, and closure phases). The closest fitting model predicts a continuum-emitting disk with an inner radius of ∼0.3 AU and a disk wind ejection region with an inner radius of ∼0.5 AU (∼17.5 stellar radii). We obtain a disk-wind half-opening angle (the angle between the rotation axis and the innermost streamline of the disk wind) of ∼80 • , which is larger than in T Tau models, and a disk inclination angle of ∼20 • (i.e., almost pole-on). Conclusions. Our observations with a spectral resolution of 12 000 allow us to study the AU-scale environment of MWC 297 in ∼10 different spectral channels across the Brγ emission line. We show that the K-band flux, visibilities, and remarkably strong phases can be explained by the employed magneto-centrifugally driven disk wind model.
Abstract. The bright star δ Sco has been considered a typical B0-type object for many years. Spectra of the star published prior to 1990 showed no evidence of emission, but only of short-term line profile variations attributed to nonradial pulsations. Speckle interferometric observations show that δ Sco is a binary system with a highlyeccentric orbit and a period of ∼10.6 years. Weak emission in the Hα line was detected in its spectrum for the first time during a periastron passage in 1990. Shortly before the next periastron passage in the summer of 2000, the binary entered a strong Hα emission and enhanced mass-loss phase. We monitored the spectroscopic development of the Be outburst from July 2000 through March 2001. In this paper we present results from our spectroscopy, refine elements of the binary orbit, and discuss possible mechanisms for the mass loss.
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