2,086 research outputs found
Everyday nationhood
Examines nationalism 'from below' in an exploration of four ways that nationhood is produced & reproduced in everyday life. The process by which the nation is constituted & legitimated as a discursive construct through 'talking the nation' is described, along with ways that nationhood frames the choices that citizens make ('choosing the nation'). The everyday meanings & invocations of national symbols constitute 'performing the nation,' while 'consuming the nation' refers to the constitution & expression of nationhood in everyday consumption practices
Endurance of SN 2005ip after a decade: X-rays, radio, and H-alpha like SN 1988Z require long-lived pre-supernova mass loss
SN2005ip was a TypeIIn event notable for its sustained strong interaction
with circumstellar material (CSM), coronal emission lines, and IR excess,
interpreted as shock interaction with the very dense and clumpy wind of an
extreme red supergiant. We present a series of late-time spectra of SN2005ip
and a first radio detection of this SN, plus late-time X-rays, all of which
indicate that its CSM interaction is still strong a decade post-explosion. We
also present and discuss new spectra of geriatric SNe with continued CSM
interaction: SN1988Z, SN1993J, and SN1998S. From 3-10 yr post-explosion,
SN2005ip's H-alpha luminosity and other observed characteristics were nearly
identical to those of the radio-luminous SN1988Z, and much more luminous than
SNe1993J and 1998S. At 10 yr after explosion, SN2005ip showed a drop in
H luminosity, followed by a quick resurgence over several months. We
interpret this variability as ejecta crashing into a dense shell located at
around 0.05 pc from the star, which may be the same shell that caused the IR
echo at earlier epochs. The extreme H-alpha luminosities in SN2005ip and
SN1988Z are still dominated by the forward shock at 10 yr post-explosion,
whereas SN1993J and SN1998S are dominated by the reverse shock at a similar
age. Continuous strong CSM interaction in SNe~2005ip and 1988Z is indicative of
enhanced mass loss for about 1e3 yr before core collapse, longer than Ne, O, or
Si burning phases. Instead, the episodic mass loss must extend back through C
burning and perhaps even part of He burning.Comment: 14 pages, 8 figs. accepted in MNRA
SN2013fs and SN2013fr: Exploring the circumstellar-material diversity in Type II supernovae
We present photometry and spectroscopy of SN2013fs and SN2013fr in the first
100 days post-explosion. Both objects showed transient, relatively narrow
H emission lines characteristic of SNeIIn, but later resembled normal
SNeII-P or SNeII-L, indicative of fleeting interaction with circumstellar
material (CSM). SN2013fs was discovered within 8hr of explosion. Its light
curve exhibits a plateau, with spectra revealing strong CSM interaction at
early times. It is a less luminous version of the transitional SNIIn PTF11iqb,
further demonstrating a continuum of CSM interaction intensity between SNeII-P
and IIn. It requires dense CSM within 6.510~cm of the
progenitor, from a phase of advanced pre-SN mass loss shortly before explosion.
Spectropolarimetry of SN2013fs shows little continuum polarization, but
noticeable line polarization during the plateau phase. SN2013fr morphed from a
SNIIn at early times to a SNII-L. After the first epoch its narrow lines
probably arose from host-galaxy emission, but the bright, narrow H
emission at early times may be intrinsic. As for SN2013fs, this would point to
a short-lived phase of strong CSM interaction if proven to be intrinsic,
suggesting a continuum between SNeIIn and II-L. It is a low-velocity SNII-L,
like SN2009kr but more luminous. SN2013fr also developed an IR excess at later
times, due to warm CSM dust that require a more sustained phase of strong
pre-SN mass loss.Comment: MNRAS accepted. 28 pages, 23 figures, 8 table
Rigorous 3D change determination in Antarctic Peninsula glaciers from stereo WorldView-2 and archival aerial imagery
This paper presents detailed elevation and volume analysis of 16 individual glaciers, grouped at four locations, spread across the Antarctic Peninsula (AP). The study makes use of newly available WorldView-2 satellite stereo imagery to exploit the previously untapped value of archival stereo aerial photography. High resolution photogrammetric digital elevation models (DEMs) are derived to determine three-dimensional glacier change over an unprecedented time span of six decades with an unparalleled mean areal coverage of 82% per glacier. The use of an in-house robust surface matching algorithm ensured rigorous alignment of the DEMs to overcome inherent problems associated with processing archival photography, most notably the identification and correction of scale error in some datasets. The analysis provides insight into one of the most challenging and data-scarce areas on the planet by expanding the spatial extent north of the AP to include previously un-studied glaciers located in the South Shetland Islands. 81% of glaciers studied showed considerable loss of volume over the period of record. The mean annual mass loss for all glaciers yielded 0.24 ± 0.08 m.w.e. per year, with a maximum mass loss of up to 62 m.w.e. and frontal retreat exceeding 2.2 km for Stadium Glacier, located furthest north on Elephant Island. Observed volumetric loss was broadly, though not always, correlated with frontal retreat. The combined mass balance of all 16 glaciers yielded − 1.862 ± 0.006 Gt, which corresponds to − 0.005 mm sea level equivalent (SLE) over the 57 year observation period
X-ray, Optical, and Radio Observations of the Type II Supernovae 1999em and 1998S
Observations of the Type II-P (plateau) Supernova (SN) 1999em and Type IIn
(narrow emission line) SN 1998S have enabled estimation of the profile of the
SN ejecta, the structure of the circumstellar medium (CSM) established by the
pre-SN stellar wind, and the nature of the shock interaction. SN 1999em is the
first Type II-P detected at both X-ray and radio wavelengths. The Chandra X-ray
data indicate non-radiative interaction of SN ejecta with a power-law density
profile (rho \propto r^{-n} with n ~ 7) with a pre-SN wind with a low mass-loss
rate of ~2 \times 10^{-6} M_sun/yr for a wind velocity of 10 km/sec, in
agreement with radio mass-loss rate estimates. The Chandra data show an
unexpected, temporary rise in the 0.4--2.0 keV X-ray flux at ~100 days after
explosion. SN 1998S, at an age of >3 years, is still bright in X-rays and is
increasing in flux density at cm radio wavelengths. Spectral fits to the
Chandra data show that many heavy elements (Ne, Al, Si, S, Ar, and Fe) are
overabundant with respect to solar values. We compare the observed elemental
abundances and abundance ratios to theoretical calculations and find that our
data are consistent with a progenitor mass of approximately 15-20 M_sun if the
heavy element ejecta are radially mixed out to a high velocity. If the X-ray
emission is from the reverse shock wave region, the supernova density profile
must be moderately flat at a velocity ~10^4 km/sec, the shock front is
non-radiative at the time of the observations, and the mass-loss rate is 1-2
\times 10^{-4} M_sun/yr for a pre-supernova wind velocity of 10 km/sec. This
result is also supported by modeling of the radio emission which implies that
SN 1998S is surrounded by a clumpy or filamentary CSM established by a high
mass-loss rate, ~2 \times 10^{-4} M_sun/yr, from the pre-supernova star.Comment: 14 pages, 10 figures, accepted by ApJ, includes new data (one new
obs. each of SN 1999em and SN 1998S), expanded discussion of spectral fit
Platelets Regulate Pulmonary Inflammation and Tissue Destruction in Tuberculosis.
RATIONALE: Platelets may interact with the immune system in tuberculosis (TB) to regulate human inflammatory responses that lead to morbidity and spread of infection. OBJECTIVES: To identify a functional role of platelets in the innate inflammatory and matrix-degrading response in TB. METHODS: Markers of platelet activation were examined in plasma from 50 patients with TB before treatment and 50 control subjects. Twenty-five patients were followed longitudinally. Platelet-monocyte interactions were studied in a coculture model infected with live, virulent Mycobacterium tuberculosis (M.tb) and dissected using qRT-PCR, Luminex multiplex arrays, matrix degradation assays, and colony counts. Immunohistochemistry detected CD41 (cluster of differentiation 41) expression in a pulmonary TB murine model, and secreted platelet factors were measured in BAL fluid from 15 patients with TB and matched control subjects. MEASUREMENTS AND MAIN RESULTS: Five of six platelet-associated mediators were upregulated in plasma of patients with TB compared with control subjects, with concentrations returning to baseline by Day 60 of treatment. Gene expression of the monocyte collagenase MMP-1 (matrix metalloproteinase-1) was upregulated by platelets in M.tb infection. Platelets also enhanced M.tb-induced MMP-1 and -10 secretion, which drove type I collagen degradation. Platelets increased monocyte IL-1 and IL-10 and decreased IL-12 and MDC (monocyte-derived chemokine; also known as CCL-22) secretion, as consistent with an M2 monocyte phenotype. Monocyte killing of intracellular M.tb was decreased. In the lung, platelets were detected in a TB mouse model, and secreted platelet mediators were upregulated in human BAL fluid and correlated with MMP and IL-1β concentrations. CONCLUSIONS: Platelets drive a proinflammatory, tissue-degrading phenotype in TB
Electronic Health Record Functionality Needed to Better Support Primary Care
Electronic health records (EHRs) must support primary care clinicians and patients, yet many clinicians remain dissatisfied with their system. This manuscript presents a consensus statement about gaps in current EHR functionality and needed enhancements to support primary care. The Institute of Medicine primary care attributes were used to define needs and Meaningful Use (MU) objectives to define EHR functionality. Current objectives remain disease- rather than whole-person focused, ignoring factors like personal risks, behaviors, family structure, and occupational and environmental influences. Primary care needs EHRs to move beyond documentation to interpreting and tracking information over time as well as patient partnering activities, support for team based care, population management tools that deliver care, and reduced documentation burden. While Stage 3 MU’s focus on outcomes is laudable, enhanced functionality is still needed including EHR modifications, expanded use of patient portals, seamless integration with external applications, and advancement of national infrastructure and policies
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