15,756 research outputs found
Formation of the Galactic Millisecond Pulsar Triple System PSR J0337+1715 - a Neutron Star with Two Orbiting White Dwarfs
The millisecond pulsar in a triple system (PSR J0337+1715, recently
discovered by Ransom et al.) is an unusual neutron star with two orbiting white
dwarfs. The existence of such a system in the Galactic field poses new
challenges to stellar astrophysics for understanding evolution, interactions
and mass-transfer in close multiple stellar systems. In addition, this system
provides the first precise confirmation for a very wide-orbit system of the
white dwarf mass-orbital period relation. Here we present a self-consistent,
semi-analytical solution to the formation of PSR J0337+1715. Our model
constrains the peculiar velocity of the system to be less than 160 km/s and
brings novel insight to, for example, common envelope evolution in a triple
system, for which we find evidence for in-spiral of both outer stars. Finally,
we briefly discuss our scenario in relation to alternative models.Comment: ApJ Letters, in press (6 pages, 3 figures, 1 table
A non-commutative Bertini theorem
We prove a version of the classical 'generic smoothness' theorem with smooth
varieties replaced by non-commutative resolutions of singular varieties. This
in particular implies a non-commutative version of the Bertini theorem.Comment: 6 pages. v2: added funder acknowledgement. Published in J.
Noncommutative Geometr
Comment on "A non-interacting low-mass black hole -- giant star binary system"
Thompson et al. (Reports, 1 November 2019, p. 637, Science) interpreted the
unseen companion of the red giant star 2MASS J05215658+4359220 as most likely a
black hole. We argue that if the red giant is about one solar mass, its
companion can be a close binary consisting of two main-sequence stars. This
would explain why no X-ray emission is detected from the system.Comment: 3 pages, Author version of Technical Comment published in Science on
8 May, 202
A unified approach to mapping and clustering of bibliometric networks
In the analysis of bibliometric networks, researchers often use mapping and
clustering techniques in a combined fashion. Typically, however, mapping and
clustering techniques that are used together rely on very different ideas and
assumptions. We propose a unified approach to mapping and clustering of
bibliometric networks. We show that the VOS mapping technique and a weighted
and parameterized variant of modularity-based clustering can both be derived
from the same underlying principle. We illustrate our proposed approach by
producing a combined mapping and clustering of the most frequently cited
publications that appeared in the field of information science in the period
1999-2008
A 10-bit Charge-Redistribution ADC Consuming 1.9 μW at 1 MS/s
This paper presents a 10 bit successive approximation ADC in 65 nm CMOS that benefits from technology scaling. It meets extremely low power requirements by using a charge-redistribution DAC that uses step-wise charging, a dynamic two-stage comparator and a delay-line-based controller. The ADC requires no external reference current and uses only one external supply voltage of 1.0 V to 1.3 V. Its supply current is proportional to the sample rate (only dynamic power consumption). The ADC uses a chip area of approximately 115--225 μm2. At a sample rate of 1 MS/s and a supply voltage of 1.0 V, the 10 bit ADC consumes 1.9 μW and achieves an energy efficiency of 4.4 fJ/conversion-step
Nutrition and Allergic Diseases
The purpose of this Special Issue, “Nutrition and Allergic Diseases”, is to provide an overview of the role of nutrition in allergy. The prevalence of asthma, rhinitis, and food allergy has increased tremendously over the last few decades. Is there a role for nutrition to help managing this global challenge? This Special Issue touches upon the many aspects that relate to nutrition and allergy and focuses on two fundamental questions: 1) Can nutrition play a role in allergy prevention and induction? 2) Can nutrition play a role in managing allergies? The topics covered range from the epidemiology of nutrition and allergy prevalence to the description of food components known to have beneficial effects on allergy, and include the importance of pregnancy and breastfeeding, the possibility of therapeutically targeting the microbiota in allergic diseases (with pre- or probiotics), the allergic effects of food processing, food allergies and related available treatments
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