The CHARA Array is a six 1 m telescope optical/IR interferometric array located on Mount Wilson, California, designed and built by the Center for High Angular Resolution Astronomy of Georgia State ...University. In this paper we describe the main elements of the Array hardware and software control systems, as well as the data reduction methods currently being used. Our plans for upgrades in the near future are also described.
We report on K-band interferometric observations of the bright, rapidly rotating star Regulus (type B7 V) made with the CHARA Array on Mount Wilson, California. Through a combination of ...interferometric and spectroscopic measurements, we have determined for Regulus the equatorial and polar diameters and temperatures, the rotational velocity and period, the inclination and position angle of the spin axis, and the gravity darkening coefficient. These first results from the CHARA Array provide the first interferometric measurement of gravity darkening in a rapidly rotating star and represent the first detection of gravity darkening in a star that is not a member of an eclipsing binary system.
Aneurysmal subarachnoid hemorrhage affects approximately 10/100,000 people per year. Endovascular coil embolization is used increasingly to treat cerebral aneurysms and its safety and durability is ...rapidly developing. The long-term durability of coil embolization of cerebral aneurysms remains in question; patients treated using this modality require multiple follow-up angiography studies and occasional repeated treatments.
Optical coherence tomography (OCT) is an emerging imaging modality that uses backscattered light to produce high-resolution tomography of optically accessible biological tissues such as the eye, luminal surface of blood vessels, and gastrointestinal tract. Vascular OCT probes in the form of imaging microwires are presently available--although not Food and Drug Administration-approved--and may be adapted for use in the cerebral circulation. In this study the authors describe the initial use of OCT to make visible the neck of aneurysms created in a canine model and treated with coil embolization. Optical coherence tomography images demonstrate changes that correlate with the histological findings of healing at the aneurysm neck and thus may be capable of demonstrating human cerebral aneurysm healing.
Optical coherence tomography may obviate the need for subsequent follow-up angiography studies as well as aid in the understanding of endovascular tissue healing. Data in this study demonstrate that further investigation of in vivo imaging with such probes is warranted.
Actinobacillus spp. are Gram-negative bacteria associated with mucosal membranes. While some are commensals, others can cause important human and animal diseases. A. pleuropneumoniae causes severe ...fibrinous hemorrhagic pneumonia in swine but not systemic disease whereas other species invade resulting in septicemia and death. To understand the invasive phenotype of Actinobacillus spp., complete genomes of eight isolates were obtained and pseudogenomes of five isolates were assembled and annotated. Phylogenetically, A. suis isolates clustered by surface antigen type and were more closely related to the invasive A. ureae, A. equuli equuli, and A. capsulatus than to the other swine pathogen, A. pleuropneumoniae. Using the LS-BSR pipeline, 251 putative virulence genes associated with serum resistance and invasion were detected.
To our knowledge, this is the first genome-wide study of the genus Actinobacillus and should contribute to a better understanding of host tropism and mechanisms of invasion of pathogenic Actinobacillus and related genera.
•Invasive Actinobacillus spp. are more closely related to one another than non-invasive spp., regardless of host specificity.•A. suis species cluster by surface antigen type.•Autotransporters, sialic acid biosynthesis/metabolism proteins, IgA protease 1, and OapA may be associated with invasion.•Common polysaccharide genes are found only in A. suis, while the transport genes are conserved in most Actinobacillus spp.
First results are presented using two new techniques for ground-based observation of Io's hotspots. An IR array camera was used to obtain direct IR images of Io with resolution better than 0.5 ...arcsec, so that more than one hotspot is seen on Io in Jupiter eclipse. The camera was also used to make the first observations of the Jupiter occultation of the hotspots. These new techniques have revealed and located at least three hotspots and will now permit routine ground-based monitoring of the locations, temperatures, and sizes of multiple hotspots on Io.
The Gulf of Maine (GOM) has seen an increasing number of introduced species, some of which have significantly impacted benthic community structure. In 2017, a number of specimens of the European ...dorid nudibranch,
Doris pseudoargus
, were observed on rocky ledges in waters off Cape Ann, Massachusetts. The presence of numerous specimens and egg masses suggested the species had been established before 2017. Additional field observations and literature searches revealed specimens occurring from Nova Scotia to the northern end of the Cape Cod Canal, which poses the question, when and where did the initial introduction take place and how? Genetic analysis confirmed the species as
Doris pseudoargus
with genomic similarities to specimens from Northern Europe. Until this introduction, the GOM had only one species of sponge feeding nudibranch,
Cadlina laevis
, which is a trophic specialist on one genus of sponge. Unlike this endemic, stenotrophic feeding dorid, the introduction of another large sized, sponge predator known to feed on diverse sponge species, that occur from the intertidal to at least 25 m in depth has the potential to significantly impact community structure over a wide variety of hard bottom habitats.
Single-beam laser Doppler measurements of flow velocity are only sensitive to the velocity component parallel to the optical axis. We describe a simple modification to a standard Doppler optical ...coherence tomography (OCT) system using a single sample beam that provides velocity information from multiple angles within the beam. By introducing a glass plate midway into the OCT beam path, the sample beam is divided into several components, each with a different group delay and each providing a separate interferogram with its own effective Doppler angle. By combining the Doppler shift measured in each of these component interferograms, the flow velocity vector is fully determined.
This case report follows a 47-year-old man who had multiple grafts undergoing FDG PET/CT (positron emission tomography/computed tomography) scan to evaluate for graft infection. Initial CT showed ...enhancing soft tissue and fluid collection around the graft, and the subsequent FDG PET/CT showed findings concerning for graft infection. This case exemplifies that FDG PET/CT is a synergistic tool in diagnosing aortic graft infections, a rare and often fatal complication of aortic grafts.
We present revised orbital elements for the massive interacting binary HD 163181, and we offer the first evidence of apsidal motion in the orbit (apsidal period
\documentclass{aastex} ...\usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \usepackageOT2,OT1{fontenc} \newcommand\cyr{ \renewcommand\rmdefault{wncyr} \renewcommand\sfdefault{wncyss} \renewcommand\encodingdefault{OT2} \normalfont \selectfont} \DeclareTextFontCommand{\textcyr}{\cyr} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} \landscape $U=510\pm 100$ \end{document}
yr). We searched for but found no obvious evidence of the secondary’s spectral lines in our optical spectra. We do observe, however, systematic profile variations with orbital phase that probably result from a gas stream from the Roche lobe–filling supergiant to the faint secondary. The relatively small projected rotational velocity of the primary (
\documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \usepackageOT2,OT1{fontenc} \newcommand\cyr{ \renewcommand\rmdefault{wncyr} \renewcommand\sfdefault{wncyss} \renewcommand\encodingdefault{OT2} \normalfont \selectfont} \DeclareTextFontCommand{\textcyr}{\cyr} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} \landscape $V\mathrm{sin}\,i=88\pm 3$ \end{document}
km s−1), the faintness of the secondary, the reported lack of orbital motion in the Hα emission, and the presence of an IR excess all suggest that the system is surrounded by an extensive circumbinary disk (as is found in a similar binary, RY Scuti).
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