5,810 research outputs found
XMM-Newton observations of the Seyfert 1 AGN H0557-385
We present XMM-Newton observations of the Seyfert 1 AGN H0557-385. We have
conducted a study into the warm absorber present in this source, and using
high-resolution RGS data we find that the absorption can be characterised by
two phases: a phase with log ionisation parameter xi of 0.50 (where xi is in
units of ergs cm/s) and a column of 0.2e21 cm^-2, and a phase with log xi of
1.62 and a column of 1.3e22 cm^-2. An iron K alpha line is detected. Neutral
absorption is also present in the source, and we discuss possible origins for
this. On the assumption that the ionised absorbers originate as an outflow from
the inner edge of the torus, we use a new method for finding the volume filling
factor. Both phases of H0557-385 have small volume filling factors (< 1%). We
also derive the volume filling factors for a sample of 23 AGN using this
assumption and for the absorbers with log xi > 0.7 we find reasonable agreement
with the filling factors obtained through the alternative method of equating
the momentum flow of the absorbers to the momentum loss of the radiation field.
By comparing the filling factors obtained by the two methods, we infer that
some absorbers with log xi < 0.7 occur at significantly larger distances from
the nucleus than the inner edge of the torus.Comment: Accepted for publication in MNRA
Multistability of free spontaneously-curved anisotropic strips
Multistable structures are objects with more than one stable conformation,
exemplified by the simple switch. Continuum versions are often elastic
composite plates or shells, such as the common measuring tape or the slap
bracelet, both of which exhibit two stable configurations: rolled and unrolled.
Here we consider the energy landscape of a general class of multistable
anisotropic strips with spontaneous Gaussian curvature. We show that while
strips with non-zero Gaussian curvature can be bistable, strips with positive
spontaneous curvature are always bistable, independent of the elastic moduli,
strips of spontaneous negative curvature are bistable only in the presence of
spontaneous twist and when certain conditions on the relative stiffness of the
strip in tension and shear are satisfied. Furthermore, anisotropic strips can
become tristable when their bending rigidity is small. Our study complements
and extends the theory of multistability in anisotropic shells and suggests new
design criteria for these structures.Comment: 20 pages, 10 figure
“CLOCK as a transformative methodology; exploring how the CLOCK initiative has transformed theory and practice in legal education”
In this panel we will consider how CLOCK has reimagined the traditional clinical legal education model, centring community legal needs within a collaborative outreach model. CLOCK was initiated at a time of crisis, when community legal needs are rising, the legal profession has limited public funding for family and social welfare law, and the regulatory framework for supervision within legal education is being revised
Unique Transcriptional Profile of Sustained Ligand-Activated Preconditioning in Pre- and Post-Ischemic Myocardium
BACKGROUND: Opioidergic SLP (sustained ligand-activated preconditioning) induced by 3–5 days of opioid receptor (OR) agonism induces persistent protection against ischemia-reperfusion (I-R) injury in young and aged hearts, and is mechanistically distinct from conventional preconditioning responses. We thus applied unbiased gene-array interrogation to identify molecular effects of SLP in pre- and post-ischemic myocardium. METHODOLOGY/PRINCIPAL FINDINGS: Male C57Bl/6 mice were implanted with 75 mg morphine or placebo pellets for 5 days. Resultant SLP did not modify cardiac function, and markedly reduced dysfunction and injury in perfused hearts subjected to 25 min ischemia/45 min reperfusion. Microarray analysis identified 14 up- and 86 down-regulated genes in normoxic hearts from SLP mice (≥1.3-fold change, FDR≤5%). Induced genes encoded sarcomeric/contractile proteins (Myh7, Mybpc3,Myom2,Des), natriuretic peptides (Nppa,Nppb) and stress-signaling elements (Csda,Ptgds). Highly repressed genes primarily encoded chemokines (Ccl2,Ccl4,Ccl7,Ccl9,Ccl13,Ccl3l3,Cxcl3), cytokines (Il1b,Il6,Tnf) and other proteins involved in inflammation/immunity (C3,Cd74,Cd83, Cd86,Hla-dbq1,Hla-drb1,Saa1,Selp,Serpina3), together with endoplasmic stress proteins (known: Dnajb1,Herpud1,Socs3; putative: Il6, Gadd45g,Rcan1) and transcriptional controllers (Egr2,Egr3, Fos,Hmox1,Nfkbid). Biological themes modified thus related to inflammation/immunity, together with cellular/cardiovascular movement and development. SLP also modified the transcriptional response to I-R (46 genes uniquely altered post-ischemia), which may influence later infarction/remodeling. This included up-regulated determinants of cellular resistance to oxidant (Mgst3,Gstm1,Gstm2) and other forms of stress (Xirp1,Ankrd1,Clu), and repression of stress-response genes (Hspa1a,Hspd1,Hsp90aa,Hsph1,Serpinh1) and Txnip. CONCLUSIONS: Protection via SLP is associated with transcriptional repression of inflammation/immunity, up-regulation of sarcomeric elements and natriuretic peptides, and modulation of cell stress, growth and development, while conventional protective molecules are unaltered
Beetroot Juice Supplementation Lowers Oxygen Cost of Vigorous Intensity Aerobic Exercise in Trained Endurance Athletes
Please see the pdf version of the abstract
Leukopenia Associated with Long-Term Colchicine Adminsitration
Purpose A case of leukopenia in a patient receiving colchicine for calcium pyrophosphate dihydrate deposition disease, or pseudogout, is reported. Summary An 85-year-old man experienced leukopenia likely due to colchicine. His medical history included chronic lymphocytic leukemia (CLL), pseudogout, osteoarthritis, and hypertension. In February 2011, his white blood cell (WBC) count was 2700 cells/μL, and his absolute neutrophil count (ANC) was 2200 cells/μL. Colchicine 0.6 mg orally daily was initiated in March for the prophylaxis of pseudogout. His WBC count decreased, and his colchicine dosage was reduced to 0.6 mg every other day. Despite this decreased dosage, his WBC count and ANC were 600 and 100 cells/μL, respectively, in September. In October, the patient received chemotherapy for presumed worsening of his CLL. One month later, his WBC count and ANC were 400 and 200 cells/μL, respectively. Subcutaneous filgrastim was administered, and colchicine was discontinued. At the end of November, he received another cycle of chemotherapy followed by pegfilgrastim. On the day of pegfilgrastim administration, the patient\u27s WBC count and ANC were 2000 and 1300 cells/μL, respectively. Two weeks later, his WBC count was 8800 cells/μL, and his ANC was 8300 cells/μL. Daily colchicine was restarted at the end of December. Two months later, his WBC count and ANC were 800 and 500 cells/μL, respectively. Given the symptomatic relief with colchicine, therapy was continued with close monitoring. Conclusion A patient with CLL developed leukopenia in association with colchicine administration for pseudogout
Fast Simulation of Facilitated Spin Models
We show how to apply the absorbing Markov chain Monte Carlo algorithm of
Novotny to simulate kinetically constrained models of glasses. We consider in
detail one-spin facilitated models, such as the East model and its
generalizations to arbitrary dimensions. We investigate how to maximise the
efficiency of the algorithms, and show that simulation times can be improved on
standard continuous time Monte Carlo by several orders of magnitude. We
illustrate the method with equilibrium and aging results. These include a study
of relaxation times in the East model for dimensions d=1 to d=13, which
provides further evidence that the hierarchical relaxation in this model is
present in all dimensions. We discuss how the method can be applied to other
kinetically constrained models.Comment: 8 pages, 4 figure
Stresses and displacements in viscoelastic bodies
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Civil Engineering, 1967.Includes bibliographical references (leaves 190-203).by James Edward Ashton.Ph.D
Microwave-assisted synthesis and electrochemical evaluation of VO2 (B) nanostructures
Understanding how intercalation materials change during electrochemical operation is paramount to optimizing their behaviour and function and in situ characterization methods allow us to observe these changes without sample destruction. Here we first report the improved intercalation properties of bronze phase vanadium dioxide VO2 (B) prepared by a microwave-assisted route which exhibits a larger electrochemical capacity (232 mAh g-1) compared with VO2 (B) prepared by a solvothermal route (197 mAh g-1). These electrochemical differences have also been followed using in situ X-ray absorption spectroscopy allowing us to follow oxidation state changes as they occur during battery operation
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