548 research outputs found
An Improved Histogram Based Boosting Detection Rate Video Watermarking Algorithm
The existing histogram based video watermarking algorithm with temporal modulated is robust to combined attacks, but the watermark detection rate is not high due to watermark cannot embedded to the smoothness and still areas effectively. To increase the watermark detection rate, in this paper, we proposed the improved algorithm of shot segmentation first and then propose an improved video watermarking algorithm which firstly construct the watermark template in each frame video in the same shot through computing block based histogram and selecting the position of the relative high variance. Then we embed the watermark template into the video frame by temporal modulation without changing the destination of the shot group of the consecutive frames. The watermark sequence is extracted by comparing the correlation distribution of video frame and corresponding watermark template in the time domain. Experimental results demonstrate that the proposed algorithm is robust to recording attacks and guarantee the watermarking video quality at the same time, besides the watermark sequences can embedded to the smoothness and still areas effectively, and the watermark detection rate can increase by about 10% than previous methods
A T-stem slip in human mitochondrial tRNA(Leu)(CUN) governs its charging capacity
The human mitochondrial tRNA(Leu)(CUN) [hmtRNA(Leu)(CUN)] corresponds to the most abundant codon for leucine in human mitochondrial protein genes. Here, in vitro studies reveal that the U48C substitution in hmtRNA(Leu)(CUN), which corresponds to the pathological T12311C gene mutation, improved the aminoacylation efficiency of hmtRNA(Leu)(CUN). Enzymatic probing suggested a more flexible secondary structure in the wild-type hmtRNA(Leu)(CUN) transcript compared with the U48C mutant. Structural analysis revealed that the flexibility of hmtRNA(Leu)(CUN) facilitates a T-stem slip resulting in two potential tertiary structures. Several rationally designed tRNA(Leu)(CUN) mutants were generated to examine the structural and functional consequences of the T-stem slip. Examination of these hmtRNA(Leu)(CUN) mutants indicated that the T-stem slip governs tRNA accepting activity. These results suggest a novel, self-regulation mechanism of tRNA structure and function
Nanoelectrode design from microminiaturized honeycomb monolith with ultrathin and stiff nanoscaffold for high-energy micro-supercapacitors
Downsizing the cell size of honeycomb monoliths to nanoscale would offer high freedom of nanostructure design beyond their capability for broad applications in different fields. However, the microminiaturization of honeycomb monoliths remains a challenge. Here, we report the fabrication of microminiaturized honeycomb monoliths-honeycomb alumina nanoscaffold- and thus as a robust nanostructuring platform to assemble active materials for microsupercapacitors. The representative honeycomb alumina nanoscaffold with hexagonal cell arrangement and 400 nm inter-cell spacing has an ultrathin but stiff nanoscaffold with only 16 ± 2 nm cell-wall-thickness, resulting in a cell density of 4.65 × 109 cells per square inch, a surface area enhancement factor of 240, and a relative density of 0.0784. These features allow nanoelectrodes based on honeycomb alumina nanoscaffold synergizing both effective ion migration and ample electroactive surface area within limited footprint. A microsupercapacitor is finally constructed and exhibits record high performance, suggesting the feasibility of the current design for energy storage devices
Probing Primordial Gravitational Waves: Ali CMB Polarization Telescope
In this paper, we will give a general introduction to the project of Ali CMB
Polarization Telescope (AliCPT), which is a Sino-US joint project led by the
Institute of High Energy Physics (IHEP) and has involved many different
institutes in China. It is the first ground-based Cosmic Microwave Background
(CMB) polarization experiment in China and an integral part of China's
Gravitational Waves Program. The main scientific goal of AliCPT project is to
probe the primordial gravitational waves (PGWs) originated from the very early
Universe.
The AliCPT project includes two stages. The first stage referred to as
AliCPT-1, is to build a telescope in the Ali region of Tibet with an altitude
of 5,250 meters. Once completed, it will be the worldwide highest ground-based
CMB observatory and open a new window for probing PGWs in northern hemisphere.
AliCPT-1 telescope is designed to have about 7,000 TES detectors at 90GHz and
150GHz. The second stage is to have a more sensitive telescope (AliCPT-2) with
the number of detectors more than 20,000.
Our simulations show that AliCPT will improve the current constraint on the
tensor-to-scalar ratio by one order of magnitude with 3 years' observation.
Besides the PGWs, the AliCPT will also enable a precise measurement on the CMB
rotation angle and provide a precise test on the CPT symmetry. We show 3 years'
observation will improve the current limit by two order of magnitude.Comment: 11 pages, 7 figures, 2 table
Terpene Synthase Gene OtLIS Confers Wheat Resistance to Sitobion avenae by Regulating Linalool Emission
peer reviewedSitobion avenae (Fabricius) is a major insect pest of wheat worldwide that reduces crop yield and quality annually.
Few germplasm resources with resistant genes to aphids have been identified and characterized. Here, octoploid Trititrigia, a species
used in wheat distant hybridization breeding, was found to be repellent to S. avenae after 2 year field investigations and associated
with physiological and behavioral assays. Linalool monoterpene was identified to accumulate dominantly in plants in response to S.
avenae infestation. We cloned the resistance gene OtLIS by assembling the transcriptome of aphid-infested or healthy octoploid
Trititrigia. Functional characterization analysis indicated that OtLIS encoded a terpene synthase and conferred resistance to S. avenae
by linalool emission before and after aphid feeding. Our study suggests that the octoploid Trititrigia with the aphid-resistant gene
OtLIS may have potential as a target resource for further breeding aphid-resistant wheat cultivars
Bioluminescence imaging of hepatitis B virus enhancer and promoter activities in mice
AbstractBy bioluminescence imaging and hydrodynamic gene transfer technology, the activities of hepatitis B virus (HBV) promoters and the effects of HBV enhancers on these promoters in mice under true physiological conditions have been assessed. Our studies reveal that either of the two HBV enhancers can stimulate HBV major promoter activity in hepa 1–6 cells (in vitro) and in mouse liver (in vivo), and the enhancer effects on the three promoters (S1, S2 and X promoter) are markedly greater in vivo than in vitro. The two HBV enhancers have no cooperative action on HBV promoters in vitro or in vivo
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