1,145 research outputs found
Normal-metal quasiparticle traps for superconducting qubits
The presence of quasiparticles in superconducting qubits emerges as an
intrinsic constraint on their coherence. While it is difficult to prevent the
generation of quasiparticles, keeping them away from active elements of the
qubit provides a viable way of improving the device performance. Here we
develop theoretically and validate experimentally a model for the effect of a
single small trap on the dynamics of the excess quasiparticles injected in a
transmon-type qubit. The model allows one to evaluate the time it takes to
evacuate the injected quasiparticles from the transmon as a function of trap
parameters. With the increase of the trap size, this time decreases
monotonically, saturating at the level determined by the quasiparticles
diffusion constant and the qubit geometry. We determine the characteristic trap
size needed for the relaxation time to approach that saturation value.Comment: 11 pages, 5 figure
TurbuStat: Turbulence Statistics in Python
We present TurbuStat (v1.0): a Python package for computing turbulence
statistics in spectral-line data cubes. TurbuStat includes implementations of
fourteen methods for recovering turbulent properties from observational data.
Additional features of the software include: distance metrics for comparing two
data sets; a segmented linear model for fitting lines with a break-point; a
two-dimensional elliptical power-law model; multi-core fast-fourier-transform
support; a suite for producing simulated observations of fractional Brownian
Motion fields, including two-dimensional images and optically-thin HI data
cubes; and functions for creating realistic world coordinate system information
for synthetic observations. This paper summarizes the TurbuStat package and
provides representative examples using several different methods. TurbuStat is
an open-source package and we welcome community feedback and contributions.Comment: Accepted in AJ. 21 pages, 8 figure
Applications of DFT to the theory of twentieth-century harmony
Music theorists have only recently, following groundbreaking work by Quinn, recognized the potential for the DFT on pcsets, initially proposed by Lewin, to serve as the foundation of a theory of harmony for the twentieth century. This paper investigates pcset “arithmetic” – subset structure, transpositional combination, and interval content – through the lens of the DFT. It discusses relationships between interval classes and DFT magnitudes, considers special properties of dyads, pcset products, and generated collections, and suggest methods of using the DFT in analysis, including interpreting DFT magnitudes, using phase spaces to understand subset structure, and interpreting the DFT of Lewin’s interval function. Webern’s op. 5/4 and Bartok’s String Quartet 4, iv, are discussed.Accepted manuscrip
Untersuchungen an den Ladungen 3 und 4 des Schnell-Thermischen Argonaut-Reaktors STARK. EUR 3701. = Studies on the charges 3 and 4 of the quick-thermal Argonaut reactor STARK. EUR 3701.
Coronary artery aneurysm: case report
<p>Abstract</p> <p>Introduction</p> <p>Aneurysms of the left main coronary artery are rare with an incidence of 0.1% in large angiographic series. The majority are atherosclerotic in origin. Other causes include connective tissue disorders, trauma, vasculitis, congenital, mycotic and idiopathic. The primary complication is myocardial ischemia or infarction, with rupture being rare. Treatment options include anticoagulation, custom made covered stents, reconstruction, resection, and exclusion with bypass.</p> <p>Case Presentation</p> <p>A 66 year-old man was referred for evaluation of a 2 Ă— 2 centimeter saccular aneurysm originating from the distal left main coronary artery. There was associated calcification and mild stenosis of the LM. The workup was prompted by a non-ST elevation myocardial infarction suffered following a laparotomy for a ruptured appendix. The past medical history was pertinent for hypertension, hyperlipidemia, and a left carotid endarterectomy.</p> <p>Cardiopulmonary bypass with hyperkalemic cardioplegic arrest was utilized. The aneurysm was exposed in the atrioventricular groove. The aneurysm was resected and oversewn. Calcification precluded patch angioplasty. The patient then underwent coronary bypass grafting with the left internal thoracic artery placed to the left anterior descending artery and a reversed greater saphenous vein graft to an obtuse marginal branch of the circumflex artery. The postoperative course was uneventful and discharge to home occurred on the fourth postoperative day. Surgical pathology confirmed an atheromatous coronary artery aneurysm.</p> <p>Conclusion</p> <p>Left main coronary artery aneurysms in adult patients are predominantly atherosclerotic in origin. The clinical presentation is that of myocardial ischemia, likely from associated embolism. Rupture is rare. Operative treatment is exclusion and revascularization.</p
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Myc Cooperates with Ras by Programming Inflammation and Immune Suppression.
The two oncogenes KRas and Myc cooperate to drive tumorigenesis, but the mechanism underlying this remains unclear. In a mouse lung model of KRasG12D-driven adenomas, we find that co-activation of Myc drives the immediate transition to highly proliferative and invasive adenocarcinomas marked by highly inflammatory, angiogenic, and immune-suppressed stroma. We identify epithelial-derived signaling molecules CCL9 and IL-23 as the principal instructing signals for stromal reprogramming. CCL9 mediates recruitment of macrophages, angiogenesis, and PD-L1-dependent expulsion of T and B cells. IL-23 orchestrates exclusion of adaptive T and B cells and innate immune NK cells. Co-blockade of both CCL9 and IL-23 abrogates Myc-induced tumor progression. Subsequent deactivation of Myc in established adenocarcinomas triggers immediate reversal of all stromal changes and tumor regression, which are independent of CD4+CD8+ T cells but substantially dependent on returning NK cells. We show that Myc extensively programs an immune suppressive stroma that is obligatory for tumor progression
Pakistani children’s experiences of growing up with Beta-Thalassemia Major
In this study, we explored the lived experiences of children with beta-thalassemia major (β-TM). We considered children as experts on their experiences in contrast to the prevalent approach of asking parents or other adults about children’s perspectives. The sample consisted of 12 children aged 8 to12 years. There were two stages to data collection. In Stage 1 we employed two focus group discussions and two role plays and analyzed the data thematically. This directly informed Stage 2, consisting of 12 in-depth interviews subjected to interpretative phenomenological analysis. From our findings we show that living with β-TM involves a continuous struggle between feelings of being different and strategies to minimize these differences to strive for normalcy. We suggest that understanding the experiences of living with β-TM from children’s perspectives can provide unique insights into their experiences, which can fill the gap in the existing, predominantly adult-oriented research on chronic illness
Nucleation of vortex arrays in rotating anisotropic Bose-Einstein condensates
The nucleation of vortices and the resulting structures of vortex arrays in
dilute, trapped, zero-temperature Bose-Einstein condensates are investigated
numerically. Vortices are generated by rotating a three-dimensional,
anisotropic harmonic atom trap. The condensate ground state is obtained by
propagating the Gross-Pitaevskii equation in imaginary time. Vortices first
appear at a rotation frequency significantly larger than the critical frequency
for vortex stabilization. This is consistent with a critical velocity mechanism
for vortex nucleation. At higher frequencies, the structures of the vortex
arrays are strongly influenced by trap geometry.Comment: 5 pages, two embedded figures. To appear in Phys. Rev. A (RC
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