390 research outputs found
Supersymmetric solutions to Euclidean Romans supergravity
We study Euclidean Romans supergravity in six dimensions with a non-trivial
Abelian R-symmetry gauge field. We show that supersymmetric solutions are in
one-to-one correspondence with solutions to a set of differential constraints
on an SU(2) structure. As an application of our results we (i) show that this
structure reduces at a conformal boundary to the five-dimensional rigid
supersymmetric geometry previously studied by the authors, (ii) find a general
expression for the holographic dual of the VEV of a BPS Wilson loop, matching
an exact field theory computation, (iii) construct holographic duals to
squashed Sasaki-Einstein backgrounds, again matching to a field theory
computation, and (iv) find new analytic solutions.Comment: 31 pages; v2: published version (with reference added
Supersymmetric gauge theories on squashed five-spheres and their gravity duals
We construct the gravity duals of large N supersymmetric gauge theories
defined on squashed five-spheres with SU(3) x U(1) symmetry. These five-sphere
backgrounds are continuously connected to the round sphere, and we find a
one-parameter family of 3/4 BPS deformations and a two-parameter family of
(generically) 1/4 BPS deformations. The gravity duals are constructed in
Euclidean Romans F(4) gauged supergravity in six dimensions, and uplift to
massive type IIA supergravity. We holographically renormalize the Romans
theory, and use our general result to compute the renormalized on-shell actions
for the solutions. The results agree perfectly with the large N limit of the
dual gauge theory partition function, which we compute using large N matrix
model techniques. In addition we compute BPS Wilson loops in these backgrounds,
both in supergravity and in the large N matrix model, again finding precise
agreement. Finally, we conjecture a general formula for the partition function
on any five-sphere background, which for fixed gauge theory depends only on a
certain supersymmetric Killing vector.Comment: 63 pages, no figures; v2: minor corrections and reference adde
Marshall University Music Department Presents the Symphonic Band Spring Concert, Gregory A. Richmond, conductor, featuring: Dr. Ben Miller, soloist, Matthew Chaffins, graduate conductor, and the world premiere of, H.M.S. Surprise Suite, by Dr. Stephen Lawson
https://mds.marshall.edu/music_perf/1449/thumbnail.jp
Enhancements in Glovebox Design Resulting from Laboratory-Conducted FIre Tests
The primary mission of the Pit Disassembly and Conversion Facility (PDCF) Project was to disassemble nuclear weapons pits and convert the resulting special nuclear materials to a form suitable for further disposition. Because of the nature of materials involved, the fundamental system which allowed PDCF to perform its mission was a series of integrated and interconnected gloveboxes which provided confinement and containment of the radioactive materials being processed. The high throughput planned for PDCF and the relatively high neutron and gamma radiation levels of the pits required that gloveboxes be shielded to meet worker dose limits. The glovebox shielding material was required to contain high hydrogen concentrations which typically result in these materials being combustible. High combustible loadings created design challenges for the facility fire suppression and ventilation system design. Combustible loading estimates for the PDCF Plutonium (Pu) Processing Building increased significantly due to these shielding requirements. As a result, the estimates of combustible loading substantially exceeded values used to support fire and facility safety analyses. To ensure a valid basis for combustible loading contributed by the glovebox system, the PDCF Project funded a series of fire tests conducted by the Southwest Research Institute on door panels and a representative glovebox containing Water Extended Polyester (WEP) radiological shielding to observe their behavior during a fire event. Improvements to PDCF glovebox designs were implemented based on lessons learned during the fire test. In particular, methods were developed to provide high levels of neutron shielding while maintaining combustible loading in the glovebox shells at low levels. Additionally, the fire test results led to design modifications to mitigate pressure increases observed during the fire test in order to maintain the integrity of the WEP cladding. These changes resulted in significantly reducing the credited combustible loading of the facility. These advances in glovebox design should be considered for application in nuclear facilities within the Department of Energy complex in the future
Effect of chronic supplementation with methylsulfonylmethane on oxidative stress following acute exercise in untrained healthy men
Objective This study was conducted to assess the effects of chronic daily methylsulfonylmethane (MSM) supplementation on known markers of oxidative stress following acute bouts of exercise in untrained healthy young men.
Methods Eighteen untrained men volunteered for this study. Participants were randomized in a double-blind placebo-controlled fashion into two groups: MSM (n = 9) and placebo (n = 9). The participants took supplementation or placebo daily for 10 days before running. Participants ran 14 km. The MSM supplementation was prepared in water at 50 mg/kg body weight. The placebo group received water. Serum malondialdehyde (MDA), protein carbonyl (PC) and plasma oxidized glutathione (GSSG) were measured as markers of oxidative stress. The plasma-reduced glutathione (GSH) level and the GSH/GSSG ratio were determined as markers of plasma antioxidant capacity.
Key Findings Acute exercise led to elevated levels of serum MDA, PC and plasma GSSG. MSM supplementation maintained PC, MDA and GSSG at lower levels after exercise than the placebo. The plasma level of GSH and the ratio of GSH/GSSG were significantly higher in the MSM supplemented group.
Conclusions These results suggest that chronic daily oral supplementation of MSM has alleviating effects on known markers of oxidative stress following acute bouts of exercise in healthy young men
A Large, Uniform Sample of X-ray Emitting AGN from the ROSAT All-Sky and Sloan Digital Sky Surveys: the Data Release 5 Sample
We describe further results of a program aimed to yield ~10^4 fully
characterized optical identifications of ROSAT X-ray sources. Our program
employs X-ray data from the ROSAT All-Sky Survey (RASS), and both optical
imaging and spectroscopic data from the Sloan Digital Sky Survey (SDSS).
RASS/SDSS data from 5740 deg^2 of sky spectroscopically covered in SDSS Data
Release 5 (DR5) provide an expanded catalog of 7000 confirmed quasars and other
AGN that are probable RASS identifications. Again in our expanded catalog, the
identifications as X-ray sources are statistically secure, with only a few
percent of the SDSS AGN likely to be randomly superposed on unrelated RASS
X-ray sources. Most identifications continue to be quasars and Seyfert 1s with
15<m<21 and 0.01<z<4; but the total sample size has grown to include very
substantial numbers of even quite rare AGN, e.g., now including several
hundreds of candidate X-ray emitting BL Lacs and narrow-line Seyfert 1
galaxies. In addition to exploring rare subpopulations, such a large total
sample may be useful when considering correlations between the X-ray and the
optical, and may also serve as a resource list from which to select the "best"
object (e.g., X-ray brightest AGN of a certain subclass, at a preferred
redshift or luminosity) for follow-on X-ray spectral or alternate detailed
studies.Comment: Accepted for publication in AJ; 32 pages, including 11 figures, and 6
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Asylum-seekers and refugees: A structuration theory analysis of their experiences in the UK
This is the peer reviewed version of the following article: Healey, R. L. (2006). Asylum-seekers and refugees: A structuration theory analysis of their experiences in the UK 2006. Population, Space and Place, 12(4), pp. 257-271, which has been published in final form at http://dx.doi.org/10.1002/psp.412 . This article may be used for non-commercial purposes in accordance With Wiley Terms and Conditions for self-archiving.Much of the literature on asylum seekers and refugees tends to be atheoretical. This article uses ideas from Giddens’ structuration theory as a conceptual framework to analyse the voices of a group of asylum seekers and refugees. The empirical database consists of semi-structured interviews with 18 asylum seekers and refugees living in the UK from a wide range of countries, including Ethiopia, Kenya, Poland, Somalia, and the Yemen. The study shows that the experiences of asylum seekers and refugees are impacted by both structural and individual agency factors. The former, it is argued, consist of public and political reaction towards the increase in the number of asylum applications, while the latter include asylum seeker and refugee experiences of specific places and people which can create social networks. Structural factors had the greatest impact upon the integration of the participants into the host society. The nature of the experiences of asylum seekers and refugees can influence the way they feel about their position in the host society. For example, negative experiences of the UK can reduce their sense of security in the society whereas positive experiences can increase their feelings of comfort. Structuration theory conceptualises how asylum seekers and refugees utilise coping strategies to raise their comfort level in the host country
Sarah: historiografkinja prošlosti i sadašnjosti žene francuskog poručnika
The article argues that Sarah, the title character of Fowles’ novel The French Lieutenant’s Woman (1969), resists the oppressive ideology of her time by writing her own historiography. In the process, not only does she emplot a tragic past for herself but she also insists on being identified as a depraved woman in the present. The analysis attempts to highlight the fact that Sarah, like a historiographer, selects the referents for her historiography—Mrs. Poulteney and Charles—and imposes her emplotment and prefiguration on her historiography of both her past and present. Employing Hayden White’s theories of postmodern historiography and Linda Hutcheon’s concept of historiographic metafiction, the paper illustrates ways in which Sarah historicizes her own past through tragic emplotment and metaphoric prefiguration of her narrative in order to convey her anarchist ideology, at the same time portraying herself as the “Woman” who has been abandoned by the French Lieutenant. Furthermore, by means of her historiography of the present, she imposes her liberal ideology through satiric emplotment of her fictional construct and ironic prefiguration of the referents of textualized oppression in society. She ironically puts Mrs. Poulteney and Charles in the situations in which their oppressive ideology is unraveled; in this way, she satirizes the codes of behavior of her present time.U članku se tvrdi da se Sarah, naslovni lik Fowlesova romana Ženska francuskog poručnika (1969), opire opresivnoj ideologiji svojega vremena pišući vlastitu historiografiju. Na taj način ona fabulira tragičnu prošlost za sebe i inzistira na tome da ju se percipira kao izopačenu ženu u sadašnjosti. Analiza pokušava istaknuti činjenicu da Sarah, poput povjesničara, odabire referente za svoju historiografiju – gđu Poulteney i Charlesa – i nameće svoju fabulaciju i prefiguraciju historiografije vlastite prošlosti i sadašnjosti. Koristeći se teorijom postmoderne historiografije Haydena Whitea i konceptom historiografske metafikcije Linde Hutcheon, rad prikazuje načine na koje Sarah historizira vlastitu prošlost kroz tragičnu fabulaciju i metaforičku prefiguraciju svoje pripovijesti kako bi istaknula svoju anarhističku ideologiju i istodobno sebe prikazala kao „žensku“ koju je napustio francuski poručnik. Nadalje, pomoću svoje historiografije sadašnjosti ona nameće svoju liberalnu ideologiju satiričkom fabulacijom svog fikcionalnog konstrukta i ironičnom prefiguracijom referenata tekstualiziranog društvenog ugnjetavanja. Na ironičan način, ona gospođu Poulteney i Charlesa stavlja u situacije u kojima se njihova represivna ideologija razotkriva; na taj način satirizira kodove
ponašanja u svojoj sadašnjosti
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