3,442 research outputs found
Morita equivalence of dual operator algebras
We consider a variant of the notion of Morita equivalence appropriate to
weak* closed algebras of Hilbert space operators, which we call {\em weak
Morita equivalence}. We obtain new variants, appropriate to the dual algebra
setting, of the basic theory of strong Morita equivalence, and new
nonselfadjoint variants of aspects of Rieffel's -algebraic Morita
equivalence.Comment: 19 pages. Revised to include a more general framework yet, to which
all of the results in the first version and most of the proofs, extend
immediatel
Intramuscular (infiltrating) Lipoma
Intraoral lipomas are benign and relatively rare tumors, although they occur with higher frequencies in other areas, most especially the back, abdomen and shoulders of adults. They have no gender predilection and predominantly affect the buccal mucosa. This paper describes a case of intramuscular (infiltrating) lipoma on the buccal mucosa of a 60-year old male which is relatively rare when compared to simple lipoma of buccal mucosa, and review pertinent literature
X-raying the coronae of HD~155555
We present an analysis of the high-resolution Chandra observation of the
multiple system, HD 155555 (an RS CVn type binary system, HD 155555 AB, and its
spatially resolved low-mass companion HD 155555 C). This is an intriguing
system which shows properties of both an active pre-main sequence star and a
synchronised (main sequence) binary. We obtain the emission measure
distribution, temperature structures, plasma densities, and abundances of this
system and compare them with the coronal properties of other young/active
stars. HD 155555 AB and HD 155555 C produce copious X-ray emission with log Lx
of 30.54 and 29.30, respectively, in the 0.3-6.0 keV energy band. The light
curves of individual stars show variability on timescales of few minutes to
hours. We analyse the dispersed spectra and reconstruct the emission measure
distribution using spectral line analysis. The resulting elemental abundances
exhibit inverse first ionisation potential effect in both cases. An analysis of
He-like triplets yields a range of coronal electron densities ~10^10-10^13
cm-3. Since HD 155555 AB is classified both as an RS CVn and a PMS star, we
compare our results with those of other slightly older active main-sequence
stars and T Tauri stars, which indicates that the coronal properties of HD
155555 AB closely resemble that of an older RS CVn binary rather than a younger
PMS star. Our results also suggests that the properties of HD 155555 C is very
similar to those of other active M dwarfs.Comment: 17 pages, 23 figues, Accepted in Ap
Agricultural growth and structural changes in the Punjab economy: an input-output analysis
Agriculture Economic aspects India Punjab., Punjab (India) Economic conditions., Input-output analysis India Punjab.,
A 33 year constancy of the X-ray coronae of AR Lac and eclipse diagnosis of scale height
Extensive X-ray and extreme ultraviolet (EUV) photometric observations of the
eclipsing RS CVn system AR Lac were obtained over the years 1997 to 2013 with
the Chandra X-ray Observatory Extreme Ultraviolet Explorer. During primary
eclipse, HRC count rates decrease by ~40%. A similar minimum is seen during one
primary eclipse observed by EUVE but not in others owing to intrinsic source
variability. Little evidence for secondary eclipses is present in either the
X-ray or EUV data, reminiscent of earlier X-ray and EUV observations. Primary
eclipses allow us to estimate the extent of a spherically symmetric corona on
the primary G star of about 1.3Rsun, or 0.86Rstar, and indicate the G star is
likely brighter than the K component by a factor of 2-5. Brightness changes not
attributable to eclipses appear to be dominated by stochastic variability and
are generally non-repeating. X-ray and EUV light curves cannot therefore be
reliably used to reconstruct the spatial distribution of emission assuming only
eclipses and rotational modulation are at work. Moderate flaring is observed,
where count rates increase by up to a factor of three above quiescence.
Combined with older ASCA, Einstein, EXOSAT, ROSAT and Beppo-SAX observations,
the data show that the level of quiescent coronal emission at X-ray wavelengths
has remained remarkably constant over 33 years, with no sign of variation due
to magnetic cycles. Variations in base level X-ray emission seen by Chandra
over 13 years are only ~10%, while variations back to pioneering Einstein
observations in 1980 amount to a maximum of 45% and more typically about 15%.Comment: To appear in the Astrophysical Journa
From Trauma to Transformation: Trauma-Informed Pedagogy in Law School
In this essay, we seek to expand the meaning of “trauma” by aligning trauma-informed pedagogy with principles of disability justice and progressive critiques of legal education. We argue first that the existence of trauma is not a sign of individual brokenness or deficiency, but rather should be taken as a warning about broken or deficient social institutions or practices. This approach to trauma recognizes the potential of those who experience trauma—whose bodies and minds bear the marks of both subordination and resilience—to contribute to institutional and structural transformation. We use as an example the trauma too often experienced in law school by students and faculty with stigmatized identities. Second, we argue that a disability justice approach to trauma calls us not only to embrace trauma-informed pedagogies for individual healing, but also to transform law teaching to accommodate the full spectrum of the human condition, using holistic pedagogical models that acknowledge the needs and capacities of human beings. Our call for structural transformation aligns with similar calls issued by feminist, critical race, and humanist critics of U.S.-style legal education
The Temperature and Density Structure of the Solar Corona. I. Observations of the Quiet Sun with the EUV Imaging Spectrometer (EIS) on Hinode
Measurements of the temperature and density structure of the solar corona
provide critical constraints on theories of coronal heating. Unfortunately, the
complexity of the solar atmosphere, observational uncertainties, and the
limitations of current atomic calculations, particularly those for Fe, all
conspire to make this task very difficult. A critical assessment of plasma
diagnostics in the corona is essential to making progress on the coronal
heating problem. In this paper we present an analysis of temperature and
density measurements above the limb in the quiet corona using new observations
from the EUV Imaging Spectrometer (EIS) on \textit{Hinode}. By comparing the Si
and Fe emission observed with EIS we are able to identify emission lines that
yield consistent emission measure distributions. With these data we find that
the distribution of temperatures in the quiet corona above the limb is strongly
peaked near 1 MK, consistent with previous studies. We also find, however, that
there is a tail in the emission measure distribution that extends to higher
temperatures. EIS density measurements from several density sensitive line
ratios are found to be generally consistent with each other and with previous
measurements in the quiet corona. Our analysis, however, also indicates that a
significant fraction of the weaker emission lines observed in the EIS
wavelength ranges cannot be understood with current atomic data.Comment: Submitted to Ap
- …