1,836 research outputs found
Asymmetric Deep Supervised Hashing
Hashing has been widely used for large-scale approximate nearest neighbor
search because of its storage and search efficiency. Recent work has found that
deep supervised hashing can significantly outperform non-deep supervised
hashing in many applications. However, most existing deep supervised hashing
methods adopt a symmetric strategy to learn one deep hash function for both
query points and database (retrieval) points. The training of these symmetric
deep supervised hashing methods is typically time-consuming, which makes them
hard to effectively utilize the supervised information for cases with
large-scale database. In this paper, we propose a novel deep supervised hashing
method, called asymmetric deep supervised hashing (ADSH), for large-scale
nearest neighbor search. ADSH treats the query points and database points in an
asymmetric way. More specifically, ADSH learns a deep hash function only for
query points, while the hash codes for database points are directly learned.
The training of ADSH is much more efficient than that of traditional symmetric
deep supervised hashing methods. Experiments show that ADSH can achieve
state-of-the-art performance in real applications
Discovery and Identification of W' and Z' in SU(2) x SU(2) x U(1) Models at the LHC
We explore the discovery potential of W' and Z' boson searches for various
SU(2) x SU(2) x U(1) models at the Large Hadron Collider (LHC), after taking
into account the constraints from low energy precision measurements and direct
searches at both the Tevatron (1.96 TeV) and the LHC (7 TeV). In such models,
the W' and Z' bosons emerge after the electroweak symmetry is spontaneously
broken. Two patterns of the symmetry breaking are considered in this work: one
is SU(2)_L x SU(2)_2 x U(1)_X to SU(2)_L x U(1)_Y (BP-I), another is SU(2)_1 x
SU(2)_2 x U(1)_Y to SU(2)_L x U(1)_Y (BP-II). Examining the single production
channel of W' and Z' with their subsequent leptonic decays, we find that the
probability of detecting W' and Z' bosons in the considered models at the LHC
(with 14 TeV) is highly limited by the low energy precision data constraints.
We show that observing Z' alone, without seeing a W', does not rule out new
physics models with non-Abelian gauge extension, such as the phobic models in
BP-I. Models in BP-II would predict the discovery of degenerate W' and Z'
bosons at the LHC.Comment: 29 pages, including 11 figures, 3 tables, added references for
introductio
Modeling of the Partial Discharge Process in a Liquid Dielectric: Effect of Applied Voltage, Gap Distance, and Electrode Type
The partial discharge (PD) process in liquid dielectrics is influenced by several factors. Although the PD current contains the information representing the discharge process during the PD event, it is difficult to determine the detailed dynamics of what is happening in the bulk of the liquid. In this paper, a microscopic model describing the dynamics of the charge carriers is implemented. The model consists of drift-diffusion equations of electrons, positive and negative ions coupled with Poisson’s equation. The stochastic feature of PD events is included in the equation. First the model is validated through comparison between the calculated PD current and experimental data. Then experiments are conducted to study the effects of the amplitude of the applied voltage, gap distance and electrode type on the PD process. The PD currents under each condition are recorded. Simulations based on the model have been conducted to analyze the dynamics of the PD events under each condition, and thus explain the mechanism of how these factors influence the PD events. The space charge generated in the PD process is revealed as the main reason affecting the microscopic process of the PD events
Long-Term Effects of Axotomy on β-Tubulin and NF Gene Expression in Rat DRG Neurons
To compare the long-term recovery of gene
expression in dorsal root ganglion (DRG)
neurons under conditions of regeneration vs.
non-regeneration, Northern blotting and in situ
hybridization were used to assess steady-state
neurofilament (NF) and beta tubulin mRNA
levels 12 weeks following axonal injury. Adult
male rats sustained either a crush lesion of the
mid-sciatic nerve (regeneration occurs), or a cut
lesion of the sciatic nerve combined with ligation
of the proximal nerve stump and removal of a
large segment of the distal nerve (regeneration
does not occur). In the latter case, neuroma
formation physically prevented axonal regeneration.
Results of Northern blotting of total RNA
obtained from the DRG indicated that NF-L and NF-Μ
mRNA levels had largely returned to
control levels at 12 weeks following crush
axotomy but were still substantially depressed
following cut/ligation injury of the sciatic nerve
at that time. in situ hybridization studies
indicated that both crush and cut/ligation
axotomy resulted in significantly lower NF-L
mRNA levels in large-sized (>1000 μm2) DRG
neurons at 12 weeks post-axotomy. Discrepancies
in the conclusions from Northern
blotting and in situ hybridization experiments
were also noted in the case of tubulin
mRNA changes at long intervals after axotomy. in situ
hybridization data derived from the large-sized
DRG neurons using a coding region β-tubulin
cDNA (which recognizes both βII
and βIII
mRNAs) showed complete recovery of β-tubulin
mRNA levels in surviving, large-sized DRG
neurons after crush axotomy, but significantly
elevated tubulin mRNA levels in surviving large
DRG cells at 12 weeks after cut/ligation
axotomy. In contrast, Northern blotting results
indicated that βII-tubulin mRNA levels in the
crush axotomy condition remained elevated
relative to control while they were substantially
lower than control in cut/ligation axotomy
samples. Results from analysis of βIII-tubulin
mRNA changes were not conclusive. The lack of
complete correspondence in the results from the
two different methods of analysis of mRNA
changes (blotting vs. in situ) is likely to be due to
selective loss of large-sized DRG neurons in the
long-standing cut/ligation injury condition. This
would influence results from blotting data,
where RNA is derived from the DRG as a whole,
more so than in situ hybridization experiments
which specifically focus on the surviving largesized
neurons. Overall, data from these
experiments indicate that altered patterns of
gene expression remain in the DRG for long
intervals after axonal injury, whether or not
axonal regeneration has been successful.
However, recovery of “normal8221; patterns of
cytoskeletal gene expression in the DRG is
considerably more complete after crush injury
than after cut/ligation injury
In vitro and in vivo antitumor properties of 7-epidocetaxel, a major impurity of docetaxel
Purpose: To investigate the antitumor properties and toxicity of 7-epi docetaxel (7-epi DTX) as an active pharmaceutical ingredient, and in formulations.Methods: Docetaxel-loaded albumin nanoparticles (DTX NPs) were prepared by freeze-drying, while 7- epi DTX was detected and isolated by high performance liquid chromatography (HPLC). Their antitumor properties were evaluated in vitro in CT26 cells and in vivo in BALB/c sk-ov-3 xenograft nude mice model. The tissues were histological examined.Results: The in vivo antitumor effects of DTX NPs at different doses of 7-epi DTX were similar. Moreover, the in vitro anti-cancer effect of 7-epi DTX was comparable to that of DTX. However, the in vivo antitumor effectiveness of 7-epi DTX was inferior to that of DTX. In toxicity studies, 7-epi DTX did not elicit any acute toxic effects both as active pharmaceutical ingredients, and as a component of formulations.Conclusion: The results indicate that 7-epi DTX does not elicit acute toxic effects both as an active pharmaceutical ingredient and in bulk formulations. The antitumor property of 7-epi DTX is less than that of DTX.Keywords: 7-Epidocetaxel, Impurity, Antitumor properties, Toxicit
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