119 research outputs found
Development of an Active Shape Model Using the Discrete Cosine Transform
Facial recognition systems have been successfully applied in security, law-enforcement and human identification application, for automatically identifying a human in a digital image or a video frame. In a feature-based face recognition system using a set of features extracted from each of the prominent facial components, automatic and accurate localization of facial features is an essential pre-processing step. The active shape model (ASM) is a flexible shape model that was originally proposed to automatically locate a set of landmarks representing the facial features. Various improved versions of this model for facial landmark annotation have been developed for increasing the shape fitting accuracy at the expense of significantly increased computational complexity.
This thesis is concerned with developing a low-complexity active shape model by incorporating the energy compaction property of the discrete cosine transform (DCT). Towards this goal, the proposed ASM, which utilizes a 2-D profile based on the DCT of the local grey-level gradient pattern around a landmark, is first developed. The ASM is then utilized in a scheme of facial landmark annotation for locating facial features of the face in an input image. The proposed ASM provides two distinct advantages: (i) the use of a smaller number of DCT coefficients in building a compressed DCT profile significantly reduces the computational complexity, and (ii) the process of choosing the low-frequency DCT coefficients filters out the noise contained in the image. Simulations are performed to demonstrate the superiority of the proposed ASM over other improved versions of the original active shape model in terms of the fitting accuracy as well as in terms of the computational complexity. It is shown that the use of the proposed model in the application of facial landmark annotation significantly reduces the execution time without affecting the accuracy of the facial shape fitting
Adaptation by stochastic switching of a monostable genetic circuit in Escherichia coli
Stochastic switching of a bistable genetic circuit represents a potential cost-saving strategy for adaptation to environmental challenges. This study reports that stochastic switching of a monostable circuit can be sufficient to mediate reversible adaptation in E. coli
A Case of Dilated Cardiomyopathy Reversed with Conversion of Atrial Fibrillation and β-blocker Therapy
Iodine containing porous organosilica nanoparticles trigger tumor spheroids destruction upon monochromatic X-ray irradiation: DNA breaks and K-edge energy X-ray
アインシュタインの光電効果をがん細胞の中で再現 放射線治療への新展開. 京都大学プレスリリース. 2021-07-14.Quantum physics helps destroy cancer cells. 京都大学プレスリリース. 2021-07-14.X-ray irradiation of high Z elements causes photoelectric effects that include the release of Auger electrons that can induce localized DNA breaks. We have previously established a tumor spheroid-based assay that used gadolinium containing mesoporous silica nanoparticles and synchrotron-generated monochromatic X-rays. In this work, we focused on iodine and synthesized iodine-containing porous organosilica (IPO) nanoparticles. IPO were loaded onto tumor spheroids and the spheroids were irradiated with 33.2 keV monochromatic X-ray. After incubation in CO₂ incubator, destruction of tumor spheroids was observed which was accompanied by apoptosis induction, as determined by the TUNEL assay. By employing the γH2AX assay, we detected double strand DNA cleavages immediately after the irradiation. These results suggest that IPO first generate double strand DNA breaks upon X-ray irradiation followed by apoptosis induction of cancer cells. Use of three different monochromatic X-rays having energy levels of 33.0, 33.2 and 33.4 keV as well as X-rays with 0.1 keV energy intervals showed that the optimum effect of all three events (spheroid destruction, apoptosis induction and generation of double strand DNA breaks) occurred with a 33.2 keV monochromatic X-ray. These results uncover the preferential effect of K-edge energy X-ray for tumor spheroid destruction mediated by iodine containing nanoparticles
Effect of Antihypertensive Agents on the Regression of Hypertensive Cardiac Hypertrophy : Comparison of Angiotensin converting enzyme(ACE) inhibitor and Ca++ blocking agent
Fructo-oligosaccharides, intestinal function, & NASH in MCD mice
Impairments in intestinal barrier function, epithelial mucins, and tight junction proteins have been reported to be associated with nonalcoholic steatohepatitis. Prebiotic fructo-oligosaccharides restore balance in the gastrointestinal microbiome. This study was conducted to determine the effects of dietary fructo-oligosaccharides on intestinal barrier function and steatohepatitis in methionine-choline-deficient mice. Three groups of 12-week-old male C57BL/6J mice were studied for 3 weeks; specifically, mice were fed a methionine-choline-deficient diet, a methionine-choline-deficient diet plus 5% fructo-oligosaccharides in water, or a normal control diet. Fecal bacteria, short-chain fatty acids, and immunoglobulin A (IgA) levels were investigated. Histological and immunohistochemical examinations were performed using mice livers for CD14 and Toll-like receptor-4 (TLR4) expression and intestinal tissue samples for IgA and zonula occludens-1 expression in epithelial tight junctions. The methionine-choline-deficient mice administered 5% fructo-oligosaccharides maintained a normal gastrointestinal microbiome, whereas methionine-choline-deficient mice without prebiotic supplementation displayed increases in Clostridium cluster XI and subcluster XIVa populations and a reduction in Lactobacillales spp. counts. Methionine-choline-deficient mice given 5% fructo-oligosaccharides exhibited significantly decreased hepatic steatosis (p = 0.003), decreased liver inflammation (p = 0.005), a decreased proportion of CD14-positive Kupffer cells (p = 0.01), decreased expression of TLR4 (p = 0.04), and increases in fecal short-chain fatty acid and IgA concentrations (p < 0.04) compared with the findings in methionine-choline-deficient mice that were not administered this prebiotic. This study illustrated that in the methionine-choline-deficient mouse model, dietary fructo-oligosaccharides can restore normal gastrointestinal microflora and normal intestinal epithelial barrier function, and decrease steatohepatitis. The findings support the role of prebiotics, such as fructo-oligosaccharides, in maintaining a normal gastrointestinal microbiome; they also support the need for further studies on preventing or treating nonalcoholic steatohepatitis using dietary fructo-oligosaccharides
Dual supermassive black holes at close separation revealed by the Hyper Suprime-Cam Subaru Strategic Program
The unique combination of superb spatial resolution, wide-area coverage, and
deep depth of the optical imaging from the Hyper Suprime-Cam (HSC) Subaru
Strategic Program is utilized to search for dual quasar candidates. Using an
automated image analysis routine on 34,476 known SDSS quasars, we identify
those with two (or more) distinct optical point sources in HSC images covering
796 deg^2. We find 421 candidates out to a redshift of 4.5 of which one hundred
or so are more likely after filtering out contaminating stars. Angular
separations of 0.6 - 4.0" correspond to projected separations of 3 - 30 kpc, a
range relatively unexplored for population studies of luminous dual quasars.
Using Keck-I/LRIS and Gemini-N/NIFS, we spectroscopically confirm three dual
quasar systems at z < 1, two of which are previously unknown out of eight
observed, based on the presence of characteristic broad emission lines in each
component, while highlighting that the continuum of one object in one of the
pairs is reddened. In all cases, the [OIII]5007 emission lines have mild
velocity offsets, thus the joint [OIII] line profile is not double-peaked. We
find a dual quasar fraction of 0.26+/-0.18% and no evidence for evolution. A
comparison with the Horizon-AGN simulation seems to support the case of no
evolution in the dual quasar fraction when broadly matching the quasar
selection. These results may indicate a scenario in which the frequency of the
simultaneous triggering of luminous quasars is not as sensitive as expected to
the cosmic evolution of the merger rate or gas content of galaxies.Comment: 11 pages; 12 figures; Accepted for publication in The Astrophysical
Journa
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