2,290 research outputs found
An interleukin-33/ST2 signaling deficiency reduces overt pain-like behaviors in mice
Interleukin (IL)-33, the most recent member of the IL family of cytokines, signals through the ST2 receptor. IL-33/ST2 signaling mediates antigen challenge-induced mechanical hyperalgesia in the joints and cutaneous tissues of immunized mice. The present study asked whether IL-33/ST2 signaling is relevant to overt pain-like behaviors in mice. Acetic acid and phenyl-p-benzoquinone induced significant writhing responses in wild-type (WT) mice; this overt nociceptive behavior was reduced in ST2-deficient mice. In an antigen-challenge model, ST2-deficient immunized mice had reduced induced flinch and licking overt pain-like behaviors. In the formalin test, ST2-deficient mice also presented reduced flinch and licking responses, compared with WT mice. Naive WT and ST2-deficient mice presented similar responses in the rota-rod, hot plate, and electronic von Frey tests, indicating no impairment of motor function or alteration in basal nociceptive responses. The results demonstrate that IL-33/ST2 signaling is important in the development of overt pain-like behaviors
Accelerating incoherent dedispersion
Incoherent dedispersion is a computationally intensive problem that appears
frequently in pulsar and transient astronomy. For current and future transient
pipelines, dedispersion can dominate the total execution time, meaning its
computational speed acts as a constraint on the quality and quantity of science
results. It is thus critical that the algorithm be able to take advantage of
trends in commodity computing hardware. With this goal in mind, we present
analysis of the 'direct', 'tree' and 'sub-band' dedispersion algorithms with
respect to their potential for efficient execution on modern graphics
processing units (GPUs). We find all three to be excellent candidates, and
proceed to describe implementations in C for CUDA using insight gained from the
analysis. Using recent CPU and GPU hardware, the transition to the GPU provides
a speed-up of 9x for the direct algorithm when compared to an optimised
quad-core CPU code. For realistic recent survey parameters, these speeds are
high enough that further optimisation is unnecessary to achieve real-time
processing. Where further speed-ups are desirable, we find that the tree and
sub-band algorithms are able to provide 3-7x better performance at the cost of
certain smearing, memory consumption and development time trade-offs. We finish
with a discussion of the implications of these results for future transient
surveys. Our GPU dedispersion code is publicly available as a C library at:
http://dedisp.googlecode.com/Comment: 15 pages, 4 figures, 2 tables, accepted for publication in MNRA
A (p,q)-deformed Landau problem in a spherical harmonic well: spectrum and noncommuting coordinates
A (p,q)-deformation of the Landau problem in a spherically symmetric harmonic
potential is considered. The quantum spectrum as well as space noncommutativity
are established, whether for the full Landau problem or its quantum Hall
projections. The well known noncommutative geometry in each Landau level is
recovered in the appropriate limit p,q=1. However, a novel noncommutative
algebra for space coordinates is obtained in the (p,q)-deformed case, which
could also be of interest to collective phenomena in condensed matter systems.Comment: 9 pages, no figures; updated reference
Solitons of Sigma Model on Noncommutative Space as Solitons of Electron System
We study the relationship of soliton solutions for electron system with those
of the sigma model on the noncommutative space, working directly in the
operator formalism. We find that some soliton solutions of the sigma model are
also the solitons of the electron system and are classified by the same
topological numbers.Comment: 12 pages, LaTeX2e, improvements to discussions, Version to be
published in JHE
Multi-scale analysis of lung computed tomography images
A computer-aided detection (CAD) system for the identification of lung
internal nodules in low-dose multi-detector helical Computed Tomography (CT)
images was developed in the framework of the MAGIC-5 project. The three modules
of our lung CAD system, a segmentation algorithm for lung internal region
identification, a multi-scale dot-enhancement filter for nodule candidate
selection and a multi-scale neural technique for false positive finding
reduction, are described. The results obtained on a dataset of low-dose and
thin-slice CT scans are shown in terms of free response receiver operating
characteristic (FROC) curves and discussed.Comment: 18 pages, 12 low-resolution figure
Low Energy Effective Action in N=2 Yang-Mills as an Integrated Anomaly
Based on chiral ring relations and anomalies, as described by Cachazo,
Douglas, Seiberg and Witten, we argue that the holomorphic effective action in
N=2 Yang-Mills theory can be understood as an integrated U(1) anomaly from a
purely field theory point of view. In particular, we show that the periods of
the Riemann surface arising from the generalized Konishi anomaly can be given a
physical interpretation without referring to special geometry. We also discuss
consequences for the multi-instanton calculus in N=2 Yang-Mills theory.Comment: 25 pages, 2 figures ; v2: reference adde
Idiopathic Myenteric Ganglionitis Underlying Acute ‘Dramatic’ Intestinal Pseudoobstruction: Report of an Exceptional Case
Inflammation of the myenteric plexus of the gastrointestinal tract is a very rare pathological condition, with few reports in the medical literature. This pathological condition causes atonic gut motor dysfunction and is principally secondary to other diseases, being reported nearly solely as a paraneoplastic phenomenon in neuroendocrine lung tumors, including small cell carcinomas or neuroblastomas. In addition it can also be associated with disorders of the central nervous system, although it has rarely been described in Chagas disease. It has been named ‘idiopathic myenteric ganglionitis’ because no apparent causes can be demonstrated. We report the clinicopathologic findings of an exceptional case of a young woman affected by severe chronic constipation suddenly changing into acute intestinal pseudoobstruction with dramatic evolution. Relationships between ganglionitis, idiopathic constipation and acute intestinal pseudoobstruction as well as therapeutic implications are discussed
Universal properties for linelike melting of the vortex lattice
Using numerical results obtained within two models describing vortex matter
(interacting elastic lines (Bose model) and uniformly frustrated XY-model) we
establish universal properties of the melting transition within the linelike
regime. These properties, which are captured correctly by both models, include
the scaling of the melting temperature with anisotropy and magnetic field, the
effective line tension of vortices in the liquid regime, the latent heat, the
entropy jump per entanglement length, and relative jump of Josephson energy at
the transition as compared to the latent heat. The universal properties can
serve as experimental fingerprints of the linelike regime of melting.
Comparison of the models allows us to establish boundaries of the linelike
regime in temperature and magnetic field.Comment: Revtex, 12 pages, 2 EPS figure
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