2,930 research outputs found
Radio Polarization of BL Lacertae objects
In this paper, using the database of the university of Michigan Radio
Astronomy Observatory (UMRAO) at three (4.8 GHz, 8 GHZ, and 14.5 GHz) radio
frequencies, we studied the polarization properties for 47 BL Lacertae
objects(38 radio selected BL Lacertae objects, 7 X-ray selected BL Lacertae,
and two inter-middle objects (Mkn 421 and Mkn 501), and found that (1) The
polarizations at higher radio frequency is higher than those at lower
frequency, (2) The variability of polarization at higher radio frequency is
higher than those at lower frequency, (3) The polarization is correlated with
the radio spectral index, and (4) The polarization is correlated with
core-dominance parameter for those objects with known core-dominance parameters
suggesting that the relativistic beaming could explain the polarization
characteristic of BL Lacs.Comment: 5 pages, 3 figures, 1 table. PASJ, in pres
Road Planning for Slums via Deep Reinforcement Learning
Millions of slum dwellers suffer from poor accessibility to urban services
due to inadequate road infrastructure within slums, and road planning for slums
is critical to the sustainable development of cities. Existing re-blocking or
heuristic methods are either time-consuming which cannot generalize to
different slums, or yield sub-optimal road plans in terms of accessibility and
construction costs. In this paper, we present a deep reinforcement learning
based approach to automatically layout roads for slums. We propose a generic
graph model to capture the topological structure of a slum, and devise a novel
graph neural network to select locations for the planned roads. Through masked
policy optimization, our model can generate road plans that connect places in a
slum at minimal construction costs. Extensive experiments on real-world slums
in different countries verify the effectiveness of our model, which can
significantly improve accessibility by 14.3% against existing baseline methods.
Further investigations on transferring across different tasks demonstrate that
our model can master road planning skills in simple scenarios and adapt them to
much more complicated ones, indicating the potential of applying our model in
real-world slum upgrading. The code and data are available at
https://github.com/tsinghua-fib-lab/road-planning-for-slums.Comment: KDD'2
Role of TRPM8 in dorsal root ganglion in nerve injury-induced chronic pain
<p>Abstract</p> <p>Background</p> <p>Chronic neuropathic pain is an intractable pain with few effective treatments. Moderate cold stimulation can relieve pain, and this may be a novel train of thought for exploring new methods of analgesia. Transient receptor potential melastatin 8 (TRPM8) ion channel has been proposed to be an important molecular sensor for cold. Here we investigate the role of TRPM8 in the mechanism of chronic neuropathic pain using a rat model of chronic constriction injury (CCI) to the sciatic nerve.</p> <p>Results</p> <p>Mechanical allodynia, cold and thermal hyperalgesia of CCI rats began on the 4th day following surgery and maintained at the peak during the period from the 10th to 14th day after operation. The level of TRPM8 protein in L5 dorsal root ganglion (DRG) ipsilateral to nerve injury was significantly increased on the 4th day after CCI, and reached the peak on the 10th day, and remained elevated on the 14th day following CCI. This time course of the alteration of TRPM8 expression was consistent with that of CCI-induced hyperalgesic response of the operated hind paw. Besides, activation of cold receptor TRPM8 of CCI rats by intrathecal application of menthol resulted in the inhibition of mechanical allodynia and thermal hyperalgesia and the enhancement of cold hyperalgesia. In contrast, downregulation of TRPM8 protein in ipsilateral L5 DRG of CCI rats by intrathecal TRPM8 antisense oligonucleotide attenuated cold hyperalgesia, but it had no effect on CCI-induced mechanical allodynia and thermal hyperalgesia.</p> <p>Conclusions</p> <p>TRPM8 may play different roles in mechanical allodynia, cold and thermal hyperalgesia that develop after nerve injury, and it is a very promising research direction for the development of new therapies for chronic neuroapthic pain.</p
Deep Domain Adversarial Adaptation for Photon-efficient Imaging
Photon-efficient imaging with the single-photon light detection and ranging
(LiDAR) captures the three-dimensional (3D) structure of a scene by only a few
detected signal photons per pixel. However, the existing computational methods
for photon-efficient imaging are pre-tuned on a restricted scenario or trained
on simulated datasets. When applied to realistic scenarios whose
signal-to-background ratios (SBR) and other hardware-specific properties differ
from those of the original task, the model performance often significantly
deteriorates. In this paper, we present a domain adversarial adaptation design
to alleviate this domain shift problem by exploiting unlabeled real-world data,
with significant resource savings. This method demonstrates superior
performance on simulated and real-world experiments using our home-built
up-conversion single-photon imaging system, which provides an efficient
approach to bypass the lack of ground-truth depth information in implementing
computational imaging algorithms for realistic applications
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