scholarly journals Surveying the Bright Stars by Optical Interferometry. III. A Magnitude-limited Multiplicity Survey of Classical Be Stars

2021 ◽  
Vol 257 (2) ◽  
pp. 69
Author(s):  
D. J. Hutter ◽  
C. Tycner ◽  
R. T. Zavala ◽  
J. A. Benson ◽  
C. A. Hummel ◽  
...  
Keyword(s):  
Literature Search ◽  
Binary Systems ◽  
Optical Interferometry ◽  
Extensive Literature ◽  
Be Stars ◽  
Primary Star ◽  
Multiple Systems ◽  
Long Baseline ◽  
Close Physical Proximity ◽  
Extensive Literature Search

Abstract We present the results of a multiplicity survey for a magnitude-limited sample of 31 classical Be stars conducted with the Navy Precision Optical Interferometer and the Mark III Stellar Interferometer. The interferometric observations were used to detect companions in 10 previously known binary systems. For two of these sources (66 Oph and β Cep) new orbital solutions were obtained, while for a third source (υ Sgr) our observations provide the first direct, visual detection of the hot companion to the primary star. Combining our interferometric observations with an extensive literature search, we conclude that an additional four sources (o Cas, 15 Mon, β Lyr, and β Cep) also contain wider binary components that are physical companions to the narrow binaries, thus forming hierarchical multiple systems. Among the sources not previously confirmed as spectroscopic or visual binaries, BK Cam was resolved on a number of nights within a close physical proximity of another star with relative motion possibly suggesting a physical binary. Combining our interferometric observations with an extensive literature search, we provide a detailed listing of companions known around each star in the sample, and discuss the multiplicity frequency in the sample. We also discuss the prospects for future multiplicity studies of classical Be stars by long-baseline optical interferometry.

scholarly journals Magnetic Suspension with Motorization to Measure the Speed of Gravity

2017 ◽  
Vol 45 ◽  
pp. 1760020
Author(s):  
Henrique Linares ◽  
Carlos Frajuca ◽  
Fabio S. Bortoli ◽  
Givanildo A. Santos ◽  
Francisco Y. Nakamoto
Keyword(s):  
High Speed ◽  
Literature Search ◽  
Magnetic Bearing ◽  
Magnetic Suspension ◽  
Extensive Literature ◽  
Sliding Bearing ◽  
Speed Of Gravity ◽  
Engineering Problems ◽  
Extensive Literature Search ◽  
Hybrid Bearing

This work aims to design a magnetic suspension for an experiment to measure gravitys velocity. Such device must rotate two objects symmetrically with the greatest mass and largest radius as possible, at the speed of [Formula: see text], which means this device falls into the high-speed machines category. The guidelines and solutions proposed in this paper constitute a contribution to this class of engineering problems and were based on an extensive literature search, contacts with experts, the tutors and author’s experience, as well as on experimental results. The main solution proposed is a hybrid bearing that combines a radial passive magnetic bearing with an axial sliding bearing, here called MPS (Magnetic Passive and Sliding) bearing.

The genus Carex (Cyperaceae) in Armenia

Phytotaxa ◽  
2021 ◽  
Vol 494 (1) ◽  
pp. 1-41
Author(s):  
JACOB KOOPMAN ◽  
TARON ALEKSANYAN ◽  
ALLA ALEKSANYAN ◽  
GEORGE FAYVUSH ◽  
MARINA OGANESIAN ◽  
...  
Keyword(s):  
Literature Search ◽  
Field Research ◽  
Extensive Literature ◽  
Extensive Literature Search

In this paper we present an updated checklist, key and maps for all the currently known Carex taxa present in Armenia. The present work is based on the revision of the vouchers in herbaria ERE, W and MW, extensive literature search, and field research carried out in 2015–2019. As a result, 71 species of Carex are known from Armenia. Besides, the first Carex hybrid in Armenia has been found and provided here with a binomial name.

scholarly journals Interferometric Investigations of Eclipsing Binaries as a Key to an Improved Distance Scale

2006 ◽  
Vol 2 (S240) ◽  
pp. 496-498
Author(s):  
K. Shabun ◽  
A. Richichi ◽  
U. Munari ◽  
A. Siviero ◽  
B. Pacsysnki
Keyword(s):  
Spectral Type ◽  
Effective Temperature ◽  
Binary Systems ◽  
Angular Separation ◽  
Eclipsing Binaries ◽  
Multiple Systems ◽  
Long Baseline ◽  
Global Calibration ◽  
Empirical Calibration ◽  
Full Solution

AbstractBinary and multiple systems constitute one of the main tools for obtaining fundamental stellar parameters, such as masses, radii, effective temperatures and distances. One especially fortunate, and at the same time rare, occurrence is that of double-lined eclipsing binaries with well-detached components. In this special case, it is possible to obtain a full solution of all orbital and stellar parameters, with the exception of the effective temperature of one star, which is normally estimated from spectral type or derived from atmospheric analysis of the spectrum. Long-baseline interferometry at facilities such as the ESO VLTI is beginning to have the capability to measure directly the angular separation and the angular diameter of some selected eclipsing binary systems, and we have proposed such observations with the AMBER instrument. In particular, we aim at deriving directly the effective temperature of at least one of the components in the proposed system, thereby avoiding any assumptions in the global solution through the Wilson–Devinney method. We will also obtain an independent check of the results of this latter method for the distance to the system. This represents the first step towards a global calibration of eclipsing binaries as distance indicators. Our results will also contribute to the effective temperature scale for hot stars. The extension of this approach to a wider sample of eclipsing binaries could provide an independent method to assess the distance to the LMC. The observations will extend accurate empirical calibration to spectral type O9 – B0.

scholarly journals A Rare Case of Advanced Urethral Diverticular Adenocarcinoma and a Review of Treatment Modalities

2019 ◽  
Vol 7 ◽  
pp. 232470961982840
Author(s):  
Fatai Oluyadi ◽  
Preethi Ramachandran ◽  
Vladmir Gotlieb
Keyword(s):  
Literature Search ◽  
Treatment Approach ◽  
Urethral Diverticulum ◽  
Treatment Modalities ◽  
Final Decision ◽  
Extensive Literature ◽  
Platinum Based Chemotherapy ◽  
Advanced Stages ◽  
Extensive Literature Search ◽  
Tract Infections

Female urethral diverticular cancer is a very rare entity with only around 100 cases reported so far in literature and accounts for <1% of all malignancies. In this article, we present a 47-year-old African American female with repeated hospital visits for urinary retention, hematuria, and urinary tract infections. Initial computed tomography imaging and cystoscopy was unremarkable except for a distended urinary bladder. Subsequent magnetic resonance imaging and corresponding cystoscopy eventually indicated the presence of a urethral diverticulum. She underwent urethral diverticulectomy and was found to have a mass arising from urethral diverticulum extending to vaginal walls. Her biopsy was suggestive of invasive adenocarcinoma in advanced stages, for which she subsequently underwent a total pelvic exenteration. Next-generation sequencing of the tumor showed CDKN2A/B loss, MSI-stable, and low TMB, thereby ruling out the options for targeted therapies. Extensive literature search and expert opinions were sought for her case since no consensus exists regarding the optimal therapeutic approach due to the rarity of this tumor. A final decision was made to treat her with platinum-based chemotherapy. Different treatment approaches including neoadjuvant chemoradiation followed by surgery, surgery followed by adjuvant chemotherapy, and surgery followed by chemoradiation have been tried. Platinum-based chemotherapy has generally been preferred based on an extensive literature search. Multimodality treatment approach seems to be the current approach to management for advanced stages for better overall survival. This case illustrates the challenges faced in making diagnosis and treatment decisions due to the rarity of this type of tumor and lack of consensus in the treatment approach.

On the value of taxonomic standardization in evolutionary studies

Paleobiology ◽  
1987 ◽  
Vol 13 (2) ◽  
pp. 169-176 ◽  
Author(s):  
Stephen J. Culver ◽  
Martin A. Buzas ◽  
Laurel S. Collins
Keyword(s):  
Benthic Foraminifera ◽  
Literature Search ◽  
Extensive Literature ◽  
Museum Collections ◽  
Duration Data ◽  
Evolutionary Studies ◽  
Extensive Literature Search

Species duration data for living benthic foraminifera derived from an extensive literature search have been compiled and analyzed to investigate rates and patterns of species origination. The same data subjected to taxonomic standardization through examination of many specimens lodged in museum collections indicate strikingly different, and more realistic, rates and patterns.Evolutionary generalizations based on data generated from the literature only are often unreliable and may be directly in opposition to reality. Extensive attempts at taxonomic standardization should be the norm in paleobiological investigations.

scholarly journals Macrolide Allergic Reactions

Pharmacy ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 135 ◽  
Author(s):  
Kristy M. Shaeer ◽  
Elias B. Chahine ◽  
Sheeba Varghese Gupta ◽  
Jonathan C. Cho
Keyword(s):  
Literature Search ◽  
Antimicrobial Agents ◽  
Cross Reactivity ◽  
Extensive Literature ◽  
Allergic Reactions ◽  
Hypersensitivity Reactions ◽  
Chemical Structures ◽  
Life Threatening ◽  
Cutaneous Reactions ◽  
Extensive Literature Search

Macrolides are antimicrobial agents that can be used to treat a variety of infections. Allergic reactions to macrolides occur infrequently but can include minor to severe cutaneous reactions as well as systemic life-threatening reactions such as anaphylaxis. Most reports of allergic reactions occurred in patients without prior exposure to a macrolide. Cross-reactivity among macrolides may occur due to the similarities in their chemical structures; however, some published literature indicates that some patients can tolerate a different macrolide. Most published reports detailed an allergic reaction to erythromycin. Desensitization protocols to clarithromycin and azithromycin have been described in the literature. The purpose of this article is to summarize macrolide-associated allergic reactions reported in published literature. An extensive literature search was conducted to identify publications linking macrolides to hypersensitivity reactions.

Cardiopulmonary bypass on a patient with malaria

Perfusion ◽  
1999 ◽  
Vol 14 (3) ◽  
pp. 219-221 ◽  
Author(s):  
Thomas J Coley ◽  
James C Hart
Keyword(s):  
Cardiopulmonary Bypass ◽  
Aortic Valve ◽  
Aortic Stenosis ◽  
Blood Cells ◽  
Literature Search ◽  
Severe Aortic Stenosis ◽  
Extensive Literature ◽  
History Of ◽  
Extensive Literature Search ◽  
Primaquine Phosphate

There are special considerations when performing cardiopulmonary bypass (CPB) on a patient with malaria. A 70-year-old female with a recent history of severe aortic stenosis was scheduled to undergo elective aortic valve replacement. One week prior to surgery, the patient developed shaking chills and fever, with a positive malaria smear. An extensive literature search was undertaken to determine the effect of CPB on a patient with active malaria, but no prior reference was found. One major concern was the lysis of red blood cells while on bypass. The surgery was performed uneventfully, following 2 weeks of treatment with primaquine phosphate.

scholarly journals Sub-Milliarcsecond Optical Astrometry and Binary Stars

1995 ◽  
Vol 166 ◽  
pp. 193-202
Author(s):  
J.T. Armstrong
Keyword(s):  
Binary Stars ◽  
Binary Systems ◽  
Optical Interferometry ◽  
Light Curves ◽  
Spectroscopic Binaries ◽  
Indirect Methods ◽  
Fundamental Parameters ◽  
Long Baseline

Long-baseline optical interferometry has made it possible to measure the visual orbits of binary stars with major axes as small as 5 mas and errors of ≲ 100 μas. Interferometers now nearing completion will extend these values to ≳ 500 μas and σa ∼ 10 μas. Observations of double-lined spectroscopic binaries with current interferometers have already yielded some mass estimates with precisions rivaling those from fitting the light curves of eclipsing double-lined systems. Luminosity estimates based on combined visual interferometric observations and velocity curves are often more precise than those from more indirect methods based on estimates of Teff. New interferometers now coming into operation will make it possible to measure fundamental parameters in dozens to hundreds of binary systems.

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