52 research outputs found
Helioseismology, solar models and neutrino fluxes
We present our results concerning a systematical analysis of helioseismic
implications on solar structure and neutrino production. We find
Y, and
gr/cm. In the interval , the quantity is
determined with and accuracy of \permille~or better. At the solar center
still one has remarkable accuracy, . We compare the predictions
of recent solar models (standard and non-standard) with the helioseismic
results. By constructing helioseismically constrained solar models, the central
solar temperature is found to be K with a conservatively
estimated accuracy of 1.4%, so that the major unceratainty on neutrino fluxes
is due to nuclear cross section and not to solar inputs.Comment: 14 pages including 9 figures, LaTex file, espcrc2.sty is needed; to
appear in Nucl. Phys. B Proc. Suppl., Proceedings of TAUP97 conference,
Laboratori Nazionali del Gran Sasso, September 199
Two-Dimensional Helioseismic Power, Phase, and Coherence Spectra of {\it Solar Dynamics Observatory} Photospheric and Chromospheric Observables
While the {\it Helioseismic and Magnetic Imager} (HMI) onboard the {\it Solar
Dynamics Observatory} (SDO) provides Doppler velocity [], continuum
intensity [], and line-depth [] observations, each of which is
sensitive to the five-minute acoustic spectrum, the {\it Atmospheric Imaging
Array} (AIA) also observes at wavelengths -- specifically the 1600 and 1700
Angstrom bands -- that are partly formed in the upper photosphere and have good
sensitivity to acoustic modes. In this article we consider the characteristics
of the spatio--temporal Fourier spectra in AIA and HMI observables for a
15-degree region around NOAA Active Region 11072. We map the
spatio--temporal-power distribution for the different observables and the HMI
Line Core [], or Continuum minus Line Depth, and the phase and coherence
functions for selected observable pairs, as a function of position and
frequency. Five-minute oscillation power in all observables is suppressed in
the sunspot and also in plage areas. Above the acoustic cut-off frequency, the
behaviour is more complicated: power in HMI is still suppressed in the
presence of surface magnetic fields, while power in HMI and the AIA bands
is suppressed in areas of surface field but enhanced in an extended area around
the active region, and power in HMI is enhanced in a narrow zone around
strong-field concentrations and suppressed in a wider surrounding area. The
relative phase of the observables, and their cross-coherence functions, are
also altered around the active region. These effects may help us to understand
the interaction of waves and magnetic fields in the different layers of the
photosphere, and will need to be taken into account in multi-wavelength local
helioseismic analysis of active regions.Comment: 18 pages, 15 figures, to be published in Solar Physic
The quest for the solar g modes
Solar gravity modes (or g modes) -- oscillations of the solar interior for
which buoyancy acts as the restoring force -- have the potential to provide
unprecedented inference on the structure and dynamics of the solar core,
inference that is not possible with the well observed acoustic modes (or p
modes). The high amplitude of the g-mode eigenfunctions in the core and the
evanesence of the modes in the convection zone make the modes particularly
sensitive to the physical and dynamical conditions in the core. Owing to the
existence of the convection zone, the g modes have very low amplitudes at
photospheric levels, which makes the modes extremely hard to detect. In this
paper, we review the current state of play regarding attempts to detect g
modes. We review the theory of g modes, including theoretical estimation of the
g-mode frequencies, amplitudes and damping rates. Then we go on to discuss the
techniques that have been used to try to detect g modes. We review results in
the literature, and finish by looking to the future, and the potential advances
that can be made -- from both data and data-analysis perspectives -- to give
unambiguous detections of individual g modes. The review ends by concluding
that, at the time of writing, there is indeed a consensus amongst the authors
that there is currently no undisputed detection of solar g modes.Comment: 71 pages, 18 figures, accepted by Astronomy and Astrophysics Revie
At the intersection of globalization and "civilizational originality' : cultural production in Putin's Russia
This special issue originates from a transnational collaboration of scholars in philology, comparative literature, social theory, sociology, anthropology, ethnography, and media studies. The collection strives to advance a research agenda built on the nexus of three intellectual and academic domains: post-Soviet Russian cultural studies', the research paradigm put forward by Cultural Studies, as well as empirical methods developed in sociology. The collection illustrates the importance of expanding the experience of Cultural Studies beyond its established spheres of national investigation, while it also speaks to the necessity to re-evaluate the hegemony of the English-language academic and cultural production on the global scale. The collection offers insights into the gamut of cultural practices and institutional environments in which Russian cultural production happens today. It shows how cultural industries and institutions in Russia are integrated into the global marketplace and transnational communities, while they also draw on and contribute to local lives and experiences by trying to create an autonomous space for symbolic production at personal and collective levels. Through diverse topics, the issue sheds light on the agency, i.e. practitioners and participants, creators and consumers, of Russian cultural production and the neoliberal practices implemented on creative work and cultural administration in Russia today. The Introduction outlines the development of academic studies on Russian cultural practices since 1991; describes main political developments shaping the cultural field in Putin's Russia; and, finally, identifies the Cultural Studies debates the editors of the collection find most productive for investigations of Russia, i.e. the instrumentalization of culture and culture as resource. Relocated in an analysis of a post-socialist society, these conceptualisations seem increasingly problematic in a situation where local and federal policies governing cultural and creative work focus simultaneously on marketization and on nationalism as the main tools of legitimizing the federal government.Peer reviewe
Regulation of Glucocorticoid Receptor Function through Assembly of a Receptor-Heat Shock Protein Complex a
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/74316/1/j.1749-6632.1993.tb32269.x.pd
PTSD improvement and substance use disorder treatment utilization in veterans: Evidence from medical record data
BackgroundClinical trials reveal posttraumatic stress disorder (PTSD) improvement leads to decreased substance use among patients with comorbid substance use disorder (SUD). Using administrative medical record data, we determined whether clinically meaningful PTSD Checklist (PCL) (≥20 points) score decreases were positively associated with SUD treatment utilization.MethodsWe used a retrospective cohort of Veterans Health Affairs (VHA) medical record data (2008-2015). PTSD Checklist (PCL) scores were used to categorize patients into those with a clinically meaningful PTSD improvement (≥20 point decrease) or not (<20 point decrease or increase). PTSD and SUD were measured by ICD-9 codes. Propensity score weighting controlled for confounding in logistic and negative binomial models that estimated the association between clinically meaningful PTSD improvement and use of SUD treatment and number of SUD clinic visits.ResultsThe 699 eligible patients were, on average, 40.4 (±13.2) years old, 66.2% white and 33.1% were married. After controlling for confounding, there was a 56% increased odds of any SUD treatment utilization among those with a PCL decrease ≥20 vs < 20 (OR = 1.56; 95%CI = 1.04-2.33) but there was no association with number of SUD treatment visits.ConclusionsClinically meaningful reductions in PTSD symptoms were associated with any SUD treatment utilization but not amount of utilization. Improvement in PTSD symptoms, independent of the treatment modality, may enable SUD treatment seeking
- …