1,441 research outputs found
Springer theory via the Hitchin fibration
In this paper, we translate the Springer theory of Weyl group representations
into the language of symplectic topology. Given a semisimple complex group G,
we describe a Lagrangian brane in the cotangent bundle of the adjoint quotient
g/G that produces the perverse sheaves of Springer theory. The main technical
tool is an analysis of the Fourier transform for constructible sheaves from the
perspective of the Fukaya category. Our results can be viewed as a toy model of
the quantization of Hitchin fibers in the Geometric Langlands program.Comment: 37 pages; to appear in Compos. Mat
Simulation of Near Horizontal Muons and Muon Bundles for the HAWC Observatory with CORSIKA
The HAWC (High Altitude Water Cerenkov) gamma ray observatory observes muons
with nearly-horizontal trajectories corresponding to zenith angles greater than
. HAWC is located at an altitude of 4100 meters a.s.l. (70 deg.
atmospheric depth of 2400 g/cm) on the extinct volcano, Sierra Negra in
Mexico. In this poster, we summarize the CORSIKA and GEANT4 as well as
toy-model based simulations performed to determine the effective area of HAWC
to muons from high zenith angle cosmic ray primaries. We are developing an
updated GEANT4 based detector response simulation that includes a model of the
volcanoes that are located near HAWC. These simulations are investigating the
capability to use muon multiplicity and rates to differentiate between the
primary particle composition (proton or iron) and measure the primary energy.Comment: Presented at the 35th International Cosmic Ray Conference (ICRC2017),
Bexco, Busan, Korea. See arXiv:1708.02572 for all HAWC contribution
Detection of Near Horizontal Muons with the HAWC Observatory
The HAWC (High Altitude Water Cherenkov) gamma ray observatory is able to
observe muons with nearly horizontal trajectories. HAWC is located at an
altitude of 4100 meters a.s.l. on the Sierra Negra volcano in Mexico. The HAWC
detector is composed of 300 water tanks, each 7.3 m in diameter and 4.5 m tall,
densely packed over a physical area of 22,000 m. Previous and current
experiments have observed high zenith angle (near horizontal) muons at or near
sea level. HAWC operates as a hodoscope able to observe multi-TeV muons at
zenith angles greater than 75 degrees. This is the first experiment to measure
near horizontal muons at high altitude and with large ( 10 m) separations
for multiple muons. These muons are distinguishable from extensive air showers
by observing near horizontal particles propagating with the speed of light. The
proximity of Sierra Negra and Pico de Orizaba volcanoes provides an additional
measurement of muons with rock overburdens of several km water equivalent. We
will present the angular distribution and rate at which HAWC observes these
muon eventsComment: Presented at the 35th International Cosmic Ray Conference (ICRC2017),
Bexco, Busan, Korea. See arXiv:1708.02572 for all HAWC contribution
Transcriptional down-regulation of suppressor of cytokine signaling (SOCS)-3 in chronic obstructive pulmonary disease
Background: Tobacco is a leading environmental factor in the initiation of respiratory diseases and causes chronic obstructive pulmonary disease (COPD). Suppressor of cytokine signaling (SOCS) family members are involved in the pathogenesis of many inflammatory diseases and SOCS-3 has been shown to play an important role in the regulation, onset and maintenance of airway allergic inflammation indicating that SOCS-3 displays a potential therapeutic target for anti-inflammatory respiratory drugs development. Since chronic obstructive pulmonary disease (COPD) is also characterized by inflammatory changes and airflow limitation, the present study assessed the transcriptional expression of SOCS-3 in COPD.
Methods: Real-time PCR was performed to assess quantitative changes in bronchial biopsies of COPD patients in comparison to unaffected controls.
Results: SOCS-3 was significantly down-regulated in COPD at the transcriptional level while SOCS-4 and SOCS-5 displayed no change.
Conclusions: It can be concluded that the presently observed inhibition of SOCS-3 mRNA expression may be related to the dysbalance of cytokine signaling observed in COPD
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