3,490 research outputs found
Semantic Lens: Instance-Centric Semantic Alignment for Video Super-Resolution
As a critical clue of video super-resolution (VSR), inter-frame alignment
significantly impacts overall performance. However, accurate pixel-level
alignment is a challenging task due to the intricate motion interweaving in the
video. In response to this issue, we introduce a novel paradigm for VSR named
Semantic Lens, predicated on semantic priors drawn from degraded videos.
Specifically, video is modeled as instances, events, and scenes via a Semantic
Extractor. Those semantics assist the Pixel Enhancer in understanding the
recovered contents and generating more realistic visual results. The distilled
global semantics embody the scene information of each frame, while the
instance-specific semantics assemble the spatial-temporal contexts related to
each instance. Furthermore, we devise a Semantics-Powered Attention
Cross-Embedding (SPACE) block to bridge the pixel-level features with semantic
knowledge, composed of a Global Perspective Shifter (GPS) and an
Instance-Specific Semantic Embedding Encoder (ISEE). Concretely, the GPS module
generates pairs of affine transformation parameters for pixel-level feature
modulation conditioned on global semantics. After that, the ISEE module
harnesses the attention mechanism to align the adjacent frames in the
instance-centric semantic space. In addition, we incorporate a simple yet
effective pre-alignment module to alleviate the difficulty of model training.
Extensive experiments demonstrate the superiority of our model over existing
state-of-the-art VSR methods.Comment: Accepted to AAAI 202
In-situ cosmogenic <sup>36</sup>Cl denudation rates of carbonates in Guizhou karst area
This study quantifies surface denudation of carbonate rocks by the first application of in-situ cosmogenic <sup>36</sup>Cl in China. Concentrations of natural Cl and in-situ cosmogenic <sup>36</sup>Cl in bare carbonates from Guizhou karst areas were measured with isotope dilution by accelerator mass spectrometer. The Cl concentration varied from 16 to 206 ppm. The <sup>36</sup>Cl concentrations were in range of (0.8–2.4)×106 atom g−1, resulting in total denudation rates of 20–50 mm ka−1 that averaged over a 104–105 a timescale. The <sup>36</sup>Cl-denudation rates showed roughly a negative correlation with the local mean temperature. This preliminary observation may suggest the variations of proportions of chemical weathering and physical erosion in denudation process, depending upon local climatic conditions
Experimental realization of optimal asymmetric cloning and telecloning via partial teleportation
We report an experimental realization of both optimal asymmetric cloning and
telecloning of single photons by making use of partial teleportation of an
unknown state. In the experiment, we demonstrate that, conditioned on the
success of partial teleportation of single photons, not only the optimal
asymmetric cloning can be accomplished, but also one of two outputs can be
transfered to a distant location, realizing the telecloning. The experimental
results represent a novel way to achieve the quantum cloning and may have
potential applications in the context of quantum communication.Comment: 4 pages and 4 figure
Expression of the microRNA-143/145 cluster is decreased in hepatitis B virus-associated hepatocellular carcinoma and may serve as a biomarker for tumorigenesis in patients with chronic hepatitis B
The aims of the present study were to identify the expression profile of microRNA (miR)‑143/145 in hepatitis B virus (HBV)‑associated hepatocellular carcinoma (HCC), explore its association with prognosis and investigate whether the serum miR‑143/145 expression levels may serve as a diagnostic indicator of HBV‑associated HCC. The microRNA (miRNA) chromatin immunoprecipitation dataset was obtained from The Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus databases, and analyzed using the Wilcoxon signed‑rank test. It was observed that the expression of miR‑143 and miR‑145 was decreased 1.5‑fold in HBV‑associated HCC samples compared with non‑tumor tissue in the TCGA and the GSE22058 datasets (P\u3c0.01). Using the reverse transcription‑quantitative polymerase chain reaction, it was further confirmed that miR‑143/145 and their host gene MIR143HG were downregulated in HBV‑associated HCC tissues compared with corresponding distal non‑tumor tissues. The lower level of miR‑143 and miR‑145 expression was associated with tumor differentiation, and may thus be responsible for a poor prognosis of patients with HBV‑associated HCC. The receiver‑operating characteristic (ROC) curves were used to explore the potential value of miR‑143 and miR‑145 as biomarkers for predicting HBV‑associated HCC tumorigenesis. In serum, miR‑143/145 were identified to be significantly decreased in patients with HBV‑associated HCC compared with negative control patients, and their associated areas under the ROC curves were calculated at 0.813 and 0.852 (P\u3c0.05), with each having a sensitivity and a specificity close to 0.80. These results indicated that the decreased expression of the miR‑143/145 cluster and their host gene MIR143HG in HBV‑associated HCC tissue was associated with prognosis, and each of these miRNAs may serve as a valuable diagnostic biomarker for predicting HBV‑associated HCC tumorigenesis
Practice with Graph-based ANN Algorithms on Sparse Data: Chi-square Two-tower model, HNSW, Sign Cauchy Projections
Sparse data are common. The traditional ``handcrafted'' features are often
sparse. Embedding vectors from trained models can also be very sparse, for
example, embeddings trained via the ``ReLu'' activation function. In this
paper, we report our exploration of efficient search in sparse data with
graph-based ANN algorithms (e.g., HNSW, or SONG which is the GPU version of
HNSW), which are popular in industrial practice, e.g., search and ads
(advertising).
We experiment with the proprietary ads targeting application, as well as
benchmark public datasets. For ads targeting, we train embeddings with the
standard ``cosine two-tower'' model and we also develop the ``chi-square
two-tower'' model. Both models produce (highly) sparse embeddings when they are
integrated with the ``ReLu'' activation function. In EBR (embedding-based
retrieval) applications, after we the embeddings are trained, the next crucial
task is the approximate near neighbor (ANN) search for serving. While there are
many ANN algorithms we can choose from, in this study, we focus on the
graph-based ANN algorithm (e.g., HNSW-type).
Sparse embeddings should help improve the efficiency of EBR. One benefit is
the reduced memory cost for the embeddings. The other obvious benefit is the
reduced computational time for evaluating similarities, because, for
graph-based ANN algorithms such as HNSW, computing similarities is often the
dominating cost. In addition to the effort on leveraging data sparsity for
storage and computation, we also integrate ``sign cauchy random projections''
(SignCRP) to hash vectors to bits, to further reduce the memory cost and speed
up the ANN search. In NIPS'13, SignCRP was proposed to hash the chi-square
similarity, which is a well-adopted nonlinear kernel in NLP and computer
vision. Therefore, the chi-square two-tower model, SignCRP, and HNSW are now
tightly integrated
Characterization of stress degradation products of curcumin and its two derivatives by UPLC–DAD–MS/MS
AbstractCurcumin and its two derivatives of PB-3 and DY-1 were subjected to the forced degradation studies under the conditions of hydrolysis (acidic and alkaline), oxidation, photolysis, and thermal stress recommended by ICH Q1A (R2) by means of UPLC–DAD–MS/MS. Three analytes and their degradation products were separated on a column of ACQUITY UPLC®BEH C18 (100mm×2.1mm, 1.7μm) with an in-line filter prior to the column using acetonitrile and 10mM ammonium acetate buffer (pH adjusted to 3.5) as a mobile phase. Both curcumin and DY-1 showed extensive degradation under alkaline condition and gave rise to two degradation products for curcumin and three for DY-1, respectively, while no degradation product was observed under other tested conditions. PB-3 was found to be unstable in acid and alkaline conditions, two degradation products in acidic hydrolytic condition and one in alkaline condition were obtained, while it was stable in photolytic, oxidative and thermal stress conditions. The degradation products of three analytes were characterized as follows by analyzing the mass fragmentation patterns of curcumin and mass analysis of the degradation products: ferulic acid and vanillin for curcumin, 3-methoxyl-4-[3-(1-tetrahydropyrrolyl)propoxyl] benzoic aldehyde, 2,2-di-(1-phenylmethyl)-3-oxo-5-[3-methoxyl-4-(3-tetrahydropyrolylpropoxyl)] pent-4-enoic acid, and tetrapyrolyl propoxyl methoxyl phenyl prop-2-enoic acid for PB-3, 3-oxo-5-[4-hydroxyl-5-methoxyl-3-(1-morpholinylmethyl)] pent-4-enoic aldehyde, 3-oxo-5-(4-hydroxyl-5-methoxyl-3-(1-morpholinylmethyl)) pent-4-enoic acid and 2-hydroxyl-3-methoxyl-5-(7-(3-methoxyl-4-hydroxylphenyl)-3,5-dioxo-4,4-dimethyl hept-1,6-dienyl) benzoic acid for DY-1, respectively. The degradation pathways of curcumin and its derivatives were presented in addition
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