16,925 research outputs found
The mass of Albireo Aa and the nature of Albireo AB: New aspects from Gaia DR2
Aims: We aim to clarify the nature of Albireo AB and specifically to decipher
whether it is an optical or physical pair. We also try to determine the mass of
Albireo Aa. Methods: We scrutinize and compare the available absolute
astrometric data (from Hipparcos and Gaia DR2) of Albireo A and B, and we
investigate the relative orbit of the pair Albireo Aa,Ac using orbit solutions
based on ground-based interferometric measurements. Results: The mass of
Albireo Aa (K3 II) is surprisingly small; only an upper limit of about 0.7
solar masses could be derived. The systemic proper motion of Aa,Ac differs from
that of component B by about 10 mas/year with an uncertainty of less than 2
mas/year. Albireo AB is therefore most probably an optical double. Conclusions:
Specific astrometric and spectroscopic follow-up observations clarifying the
surprising mass estimate for Albireo Aa are recommended.Comment: 4 pages, 3 figures, accepted by Astron. Astrophy
Another attempt to quantify the benefits of reducing inflation
This article estimates the benefits of reducing U.S. inflation below its current level when the government simultaneously raises another distortionary tax. Other researchers have suggested that reducing inflation would have fairly large benefits—from 1 to 3 percent of gross domestic product. But that result depends on the unrealistic assumption that the government would replace inflation with a lump-sum tax, one which does not affect people's incentives. If, instead, inflation is replaced with an increase in the labor income tax, then the welfare gains that can be expected from reducing inflation below its current level are much smaller—from one-third to one-half of 1 percent of gross domestic product.Inflation (Finance)
A review of neuroleptic malignant syndrome : incidence and features in Malta
This paper describes Malta’s first sample of Neuroleptic Malignant Syndrome (NMS) and reviews the current literature. A retrospective sample of all diagnosed cases of NMS was reviewed using Pope’s (1986) criteria. Twelve cases were identified yielding an incidence of 0.67%. The range of associated risk factors and complications agreed with other reports. There were also two cases of uncontrolled diabetes. Treatments commonly used were Bromocriptine and Levodopa. There were no deaths due to NMS and no recurrence on re-exposure. The sample is too small to draw any statistically significant conclusions, however, the results are mostly in line with those obtained from larger samples. Malta’s incidence is towards the lower end of the reported range of 0.02% to 3.23%, but higher than that reported in centres trying to recognise NMS early and reduce risk factors. This suggests that Malta could benefit from trying to adopt such measures. Given Malta’s small size, it would be relatively easy to disseminate such information. This study, despite its comprehensive sample, failed to reveal any other reported cases. Nor has it been demonstrated that diabetics were at higher risk of developing NMS or its complications. It would be important to explore these possibilities further in future studies.peer-reviewe
Orbital effect of magnetic field on the Majorana phase diagram
Studies of Majorana bound states in semiconducting nanowires frequently
neglect the orbital effect of magnetic field. Systematically studying its role
leads us to several conclusions for designing Majoranas in this system.
Specifically, we show that for experimentally relevant parameter values orbital
effect of magnetic field has a stronger impact on the dispersion relation than
the Zeeman effect. While Majoranas do not require a presence of only one
dispersion subband, we observe that the size of the Majoranas becomes
unpractically large, and the band gap unpractically small when more than one
subband is filled. Since the orbital effect of magnetic field breaks several
symmetries of the Hamiltonian, it leads to the appearance of large regions in
parameter space with no band gap whenever the magnetic field is not aligned
with the wire axis. The reflection symmetry of the Hamiltonian with respect to
the plane perpendicular to the wire axis guarantees that the wire stays gapped
in the topologically nontrivial region as long as the field is aligned with the
wire.Comment: 5 pages, 6 figures, data available at
http://dx.doi.org/10.4121/uuid:20f1c784-1143-4c61-a03d-7a3454914ab
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