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Salient object detection is a fundamental problem in computer vision. Existing methods using only low-level features failed to uniformly highlight the salient object regions. In order to combine high-level saliency priors and low-level appearance cues, we propose a novel Background Prior based Salient detection method (BPS) for high-quality salient object detection. Different from other background prior based methods, a background estimation is added before performing saliency detection. We utilize the distribution of bounding boxes generated by a generic object proposal method to obtain background information. Three background priors are mainly considered to model the saliency, namely background connectivity prior , background contrast prior and spatial distribution prior , allowing the proposed method to highlight the salient object as a whole and suppress background clutters. Experiments conducted on two benchmark datasets validate that our method outperforms 11 state-of-the-art methods, while being more efficient than most leading methods. [ABSTRACT FROM AUTHOR]

Reactive oxygen species (ROSs) are generated in organisms in response to infections caused by invading microbes. However, excessive ROSs will inflict oxidative damage on the host. Peroxiredoxins (Prxs) are antioxidative enzymes that may eliminate ROSs efficiently. In this study, ApPrx1 from the pea aphid Acyrthosiphon pisum was cloned, and its function was investigated in vitro and in vivo . In the presence of DTT, recombinant ApPrx1 protein from Escherichia coli showed antioxidative activity by eliminating H 2 O 2 effectively. The H 2 O 2 levels were significantly higher in Micrococcus luteus -infected aphids than in uninfected aphids, and ApPrx1 expression was remarkably up-regulated when the aphids were infected with M. luteus or injected with H 2 O 2 . When ApPrx1 expression was reduced by dsRNA injection, the survival of the aphids decreased significantly after M. luteus infection. Knockdown of ApPrx1 decreased M. luteus loads inside the aphids 48 h post-infection. While under infection conditions, the H 2 O 2 levels were much higher in ApPrx1 knockdown aphids than in dsGFP -injected aphids, indicating that the decreased survival of the aphids was caused by increased oxidative stress. Taken together, our results reveal that ApPrx1 plays a protective role in oxidative stress caused by bacterial infection. [ABSTRACT FROM AUTHOR]

Highlights: [•] A new common visual patterns (CVPs) discovery framework is proposed. [•] It contains three successive steps: initialization, expansion and combination. [•] It can effectively deal with image photometric and geometric transformations. [•] The CVPs can be used for object recognition and near-duplicate image retrieval. [ABSTRACT FROM AUTHOR]

Antibiotics have become a global public concern because of their extensively usage and high toxicity on aquatic organisms, especially leading to the widespread of antibiotic resistance genes. The objective of this study was to evaluate the occurrence, spatial distribution and ecological risks of multi-classes commonly used human and veterinary antibiotics in both aqueous and sedimentary phases of 65 shallow lakes in the lower-middle reaches of the Yangtze River, China. In the target area, antibiotic concentrations in most of lakes (<20 ng/L in the water of 22 lakes and <20 ng/g in the sediments of 43 lakes) were generally lower than those documented in previous studies in China and other countries, and these differences were probably due to less pollutant sources, high temperatures and heavy rainfall in summer. The concentrations of antibiotics in water (>100 ng/L) or sediments (>100 ng/g) of nine lakes, such as Dianshan Lake, Ge Lake and Ce Lake, were comparable to those in rivers and lakes that were seriously polluted by urban and livestock wastewater in China. The Taihu lakes showed relatively higher antibiotic concentrations, followed by the Huaihe River lakes, Poyang lakes and Dongting lakes. The composition of antibiotics showed that agricultural source might be the main source of antibiotics in most of the lakes in the lower-middle reaches of the Yangtze River basin, China. The pseudo distribution coefficient (P- K d) and significant relationship between antibiotics and environmental factors in the present study suggested the spatial of antibiotics in the lakes might be affected by antibiotics' physiochemical properties and environmental factors. The environmental risk assessment results showed that in general, sulfamethoxazole (SMX), erythromycin (ETM) and ofloxacin (OFX) in the surface water could pose medium risks to algae or bacteria in the aquatic ecosystem, while antibiotics ETM, roxithromycin (RTM), enrofloxacin (EFX) and sulfadiazine (SDZ) in the sediment might pose medium risks to algae or bacteria populations. High potential risk might occur in winter in most lakes due to lower water storage and less degradation. Overall, our study reveals the pollution trends and potential sources of antibiotics in shallow lakes in the lower-middle reaches of the Yangtze River basin. Image 1 • Twenty five and 26 antibiotics were detected in water and sediments of 65 lakes. • Nine lakes were found with high total concentrations of antibiotics in summer. • Trends of antibiotics in lakes related with environmental factors and K d. • Antibiotics in the water and sediment posed medium risks to algae/bacteria in lakes. • High potential risk might occur in most lakes in winter due to low water volume. [ABSTRACT FROM AUTHOR]

Abstract: The issue of personal privacy has garnered significant attention with the extensive application of video surveillance systems. Privacy region scrambling is an effective method to protect privacy in video. To ensure that nonprivacy regions are not affected by scrambling, particular methods must be taken to prevent drift error in privacy protected video scrambling. However, existing methods have significantly reduced the coding efficiency. In this paper, we focus on improving coding efficiency while preventing drift error in privacy protected H.264/AVC video scrambling, which is the state-of-the-art coding standard. A restricted video coding scheme is proposed, which involves three parts of Mode Restricted Intra Prediction (MRIP), Search Window Restricted Motion Estimation (SWRME) and Boundary Strength Restricted Deblocking Filtering (BSRDF). Experimental results show that the proposed restricted video coding scheme prevents drift error with higher coding efficiency than others. [Copyright &y& Elsevier]

A new integer 4×4 transform is adopted in the new video coding standard H.264/AVC. It consumes a big account of computation of a real-time encoder. To reduce the computation load of the new transform, pruned DCT algorithm is applied. To avoid serious encoding performance loss, a new condition is derived based on statistical sum of absolute value test(SSAVT) to identify pruned block adaptively. Considering the variance of DCT coefficients’ contribution, a novel efficient model based on statistical analysis is proposed. To achieve further control on DCT complexity and a good tradeoff between performance and computation load, a scheme to control the complexity of DCT is presented. Simulation results show that the novel statistical model can save more computation, so it is chose to control DCT complexity. Simulation results show that the complexity controllable scheme can control the complexity of DCT within the specified target with negligible encoding performance loss. [Copyright &y& Elsevier]