289 research outputs found
Supervised Hashing with End-to-End Binary Deep Neural Network
Image hashing is a popular technique applied to large scale content-based
visual retrieval due to its compact and efficient binary codes. Our work
proposes a new end-to-end deep network architecture for supervised hashing
which directly learns binary codes from input images and maintains good
properties over binary codes such as similarity preservation, independence, and
balancing. Furthermore, we also propose a new learning scheme that can cope
with the binary constrained loss function. The proposed algorithm not only is
scalable for learning over large-scale datasets but also outperforms
state-of-the-art supervised hashing methods, which are illustrated throughout
extensive experiments from various image retrieval benchmarks.Comment: Accepted to IEEE ICIP 201
Selective Deep Convolutional Features for Image Retrieval
Convolutional Neural Network (CNN) is a very powerful approach to extract
discriminative local descriptors for effective image search. Recent work adopts
fine-tuned strategies to further improve the discriminative power of the
descriptors. Taking a different approach, in this paper, we propose a novel
framework to achieve competitive retrieval performance. Firstly, we propose
various masking schemes, namely SIFT-mask, SUM-mask, and MAX-mask, to select a
representative subset of local convolutional features and remove a large number
of redundant features. We demonstrate that this can effectively address the
burstiness issue and improve retrieval accuracy. Secondly, we propose to employ
recent embedding and aggregating methods to further enhance feature
discriminability. Extensive experiments demonstrate that our proposed framework
achieves state-of-the-art retrieval accuracy.Comment: Accepted to ACM MM 201
Antibacterial activities of ethanolic extract of four species of Rutaceae family
In this study, the antibacterial activity of ethanolic extract from the leaves of four Rutaceae species, including Acronychia pedunculata, Clausena excavata, Glycosmis pentaphylla and Luvunga scandens, were performed using the agar disk diffusion method for the first time. The ethanolic extracts from the leaves of A. pedunculata and G. pentaphylla were able to resist against all six bacterial strains with zones of inhibition for Bacillus cereus (17.3±2.1 mm, 20.8±1.0 mm) Staphylococcus aureus (8.5±0.5 mm, 17.6±0.3 mm) Escherichia coli (16.7±2.1 mm, 15.3±1.2 mm), Pseudomonas aeruginosa (11.7±0.6 mm, 14.0±1.7 mm), Salmonella enteritidis (22.3±0.6 mm, 24.6±0.5 mm) and Salmonella typhimurium (9.5±0.9 mm, 8.3±0.6 mm). On the other hand, the ethanolic extract of C. excavata leaf was resistant to B. cereus (12.3±0.6 mm), S. aureus (11.6±0.5 mm), E. coli (11.5±2.1 mm), P. aeruginosa (10.6±0.3 mm) while B. cereus (8.2±0.3 mm), S. aureus (9.3±0.6 mm), E. coli (8.5±0.5 mm) and S. typhimurium (8.3±0.6 mm) were inhibited by the ethanolic extract of L. scandens leaf. This study could provide necessary information for further application of these species in medicine
Optimising the Use of TRIzol-extracted Proteins in Surface Enhanced Laser Desorption/ Ionization (SELDI) Analysis
BACKGROUND: Research with clinical specimens is always hampered by the limited availability of relevant samples, necessitating the use of a single sample for multiple assays. TRIzol is a common reagent for RNA extraction, but DNA and protein fractions can also be used for other studies. However, little is known about using TRIzol-extracted proteins in proteomic research, partly because proteins extracted from TRIzol are very resistant to solubilization. RESULTS: To facilitate the use of TRIzol-extracted proteins, we first compared the ability of four different common solubilizing reagents to solubilize the TRIzol-extracted proteins from an osteosarcoma cell line, U2-OS. Then we analyzed the solubilized proteins by Surface Enhanced Laser Desorption/ Ionization technique (SELDI). The results showed that solubilization of TRIzol-extracted proteins with 9.5 M Urea and 2% CHAPS ([3-[(3-cholamidopropyl)-dimethylammonio]propanesulfonate]) (UREA-CHAPS) was significantly better than the standard 1% SDS in terms of solubilization efficiency and the number of detectable ion peaks. Using three different types of SELDI arrays (CM10, H50, and IMAC-Cu), we demonstrated that peak detection with proteins solubilized by UREA-CHAPS was reproducible (r > 0.9). Further SELDI analysis indicated that the number of ion peaks detected in TRIzol-extracted proteins was comparable to a direct extraction method, suggesting many proteins still remain in the TRIzol protein fraction. CONCLUSION: Our results suggest that UREA-CHAPS performed very well in solubilizing TRIzol-extracted proteins for SELDI applications. Protein fractions left over after TRIzol RNA extraction could be a valuable but neglected source for proteomic or biochemical analysis when additional samples are not available
Dividend Policy and the COVID-19 Crisis
This paper examines dividend payment behavior of the S&P1500 firms during the COVID-19 crisis characterized by the stock market crash and a V-shaped stock price recovery propelled by technology stocks. We find that the great majority of firms either maintain or increase the level of dividend payment during the crisis period. Yet, the relationship between the dividend payout and bottom-line earnings available to common shareholders is significantly negative. This relationship holds even for dividend-increasing firms whose earnings streams should be relatively higher (or increasing) compared to other firms in the sample. We also find that forecast earnings of up to one year in the future are negatively associated with the current dividend level implying that the existing payout policies are unsustainable. Interestingly, we document similar patterns for stock repurchases
Di-(2 ethylhexyl) phthalate and flutamide alter gene expression in the testis of immature male rats
We previously demonstrated that the androgenic and anti-androgenic effects of endocrine disruptors (EDs) alter reproductive function and exert distinct effects on developing male reproductive organs. To further investigate these effects, we used an immature rat model to examine the effects of di-(2 ethylhexyl) phthalate (DEHP) and flutamide (Flu) on the male reproductive system. Immature male SD rats were treated daily with DEHP and Flu on postnatal days (PNDs) 21 to 35, in a dose-dependent manner. As results, the weights of the testes, prostate, and seminal vesicle and anogenital distances (AGD) decreased significantly in response to high doses of DEHP or Flu. Testosterone (T) levels significantly decreased in all DEHP- treated groups, whereas luteinizing hormone (LH) plasma levels were not altered by any of the two treatments at PND 36. However, treatment with DEHP or Flu induced histopathological changes in the testes, wherein degeneration and disorders of Leydig cells, germ cells and dilatation of tubular lumen were observed in a dose-dependent manner. Conversely, hyperplasia and denseness of Leydig, Sertoli and germ cells were observed in rats given with high doses of Flu. The results by cDNA microarray analysis indicated that 1,272 genes were up-regulated by more than two-fold, and 1,969 genes were down-regulated in response to DEHP, Flu or both EDs. These genes were selected based on their markedly increased or decreased expression levels. These genes have been also classified on the basis of gene ontology (e.g., steroid hormone biosynthetic process, regulation of transcription, signal transduction, metabolic process, biosynthetic process...). Significant decreases in gene expression were observed in steroidogenic genes (i.e., Star, Cyp11a1 and Hsd3b). In addition, the expression of a common set of target genes, including CaBP1, Vav2, Plcd1, Lhx1 and Isoc1, was altered following exposure to EDs, suggesting that they may be marker genes to screen for the anti-androgenic or androgenic effects of EDs. Overall, our results demonstrated that exposure to DEHP, Flu or both EDs resulted in a alteration of gene expression in the testes of immature male rats. Furthermore, the toxicological effects of these EDs on the male reproductive system resulted from their anti-androgenic effects. Taken together, these results provide a new insight into the molecular mechanisms underlying the detrimental impacts of EDs, in regards to anti-androgenic effects in humans and wildlife
A quasi real-time approach to investigating the damage and fracture process in plain concrete by X-ray tomography
In most concrete-related computer tomography (CT) experiments, detailed information on the damage and fracture process is obtained using nonreal-time approaches, with the CT method constantly regarded as a qualitative method. This study develops a quasi real-time method with the use of experimental instruments. The average CT number is used to analyse the damage and fracture process in concrete specimens and the theory that underlies concrete damage and fracture is improved. Various characteristics of the fracture form in different loading cases are investigated at the macro and micro levels. This study provides a convenient and fast method for qualitatively and quantitatively analysing concrete.
First published online: 01 Jun 201
Anti-viral activity of Hydnellum concrescens, a medicinal mushroom
Trafficking of viral glycoprotein to the surface of infected-cells results in syncytium formation in Newcastle disease virus (NDV)-infected baby hamster kidney (BHK) cells. Hydnellum concrescens, known as a medicinal mushroom, inhibited not only syncytium formation, but also trafficking of glycoprotein, hemagglutinin-neuramidase (HN) to the cell-surface. Viral glycoprotein is processed within the endoplasmic reticulum during routing into surface. Fungal extracts showed inhibitory activities (IC50 15µg/ml) against α-glucosidase. This suggested that H. concrescens extracts inhibited the cell-surface expression of NDV-HN glycoprotein without significantly affecting HN glycoprotein synthesis in NDV-infected BHK cells.Key words: α-Glucosidase inhibitor, Hydnellum concrescens, trafficking inhibitor
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