Aggregated Text Transformer for Scene Text Detection

This paper explores the multi-scale aggregation strategy for scene text detection in natural images. We present the Aggregated Text TRansformer(ATTR), which is designed to represent texts in scene images with a multi-scale self-attention mechanism. Starting from the image pyramid with multiple resolutions, the features are first extracted at different scales with shared weight and then fed into an encoder-decoder architecture of Transformer. The multi-scale image representations are robust and contain rich information on text contents of various sizes. The text Transformer aggregates these features to learn the interaction across different scales and improve text representation. The proposed method detects scene texts by representing each text instance as an individual binary mask, which is tolerant of curve texts and regions with dense instances. Extensive experiments on public scene text detection datasets demonstrate the effectiveness of the proposed framework

Progressive Scene Text Erasing with Self-Supervision

Scene text erasing seeks to erase text contents from scene images and current state-of-the-art text erasing models are trained on large-scale synthetic data. Although data synthetic engines can provide vast amounts of annotated training samples, there are differences between synthetic and real-world data. In this paper, we employ self-supervision for feature representation on unlabeled real-world scene text images. A novel pretext task is designed to keep consistent among text stroke masks of image variants. We design the Progressive Erasing Network in order to remove residual texts. The scene text is erased progressively by leveraging the intermediate generated results which provide the foundation for subsequent higher quality results. Experiments show that our method significantly improves the generalization of the text erasing task and achieves state-of-the-art performance on public benchmarks

DDT: Dual-branch Deformable Transformer for Image Denoising

Transformer is beneficial for image denoising tasks since it can model long-range dependencies to overcome the limitations presented by inductive convolutional biases. However, directly applying the transformer structure to remove noise is challenging because its complexity grows quadratically with the spatial resolution. In this paper, we propose an efficient Dual-branch Deformable Transformer (DDT) denoising network which captures both local and global interactions in parallel. We divide features with a fixed patch size and a fixed number of patches in local and global branches, respectively. In addition, we apply deformable attention operation in both branches, which helps the network focus on more important regions and further reduces computational complexity. We conduct extensive experiments on real-world and synthetic denoising tasks, and the proposed DDT achieves state-of-the-art performance with significantly fewer computational costs.Comment: The code is avaliable at: https://github.com/Merenguelkl/DD

Covariation in Plant Functional Traits and Soil Fertility within Two Species-Rich Forests

The distribution of plant species along environmental gradients is expected to be predictable based on organismal function. Plant functional trait research has shown that trait values generally vary predictably along broad-scale climatic and soil gradients. This work has also demonstrated that at any one point along these gradients there is a large amount of interspecific trait variation. The present research proposes that this variation may be explained by the local-scale sorting of traits along soil fertility and acidity axes. Specifically, we predicted that trait values associated with high resource acquisition and growth rates would be found on soils that are more fertile and less acidic. We tested the expected relationships at the species-level and quadrat-level (20×20 m) using two large forest plots in Panama and China that contain over 450 species combined. Predicted relationships between leaf area and wood density and soil fertility were supported in some instances, but the majority of the predicted relationships were rejected. Alternative resource axes, such as light gradients, therefore likely play a larger role in determining the interspecific variability in plant functional traits in the two forests studied

Developing a genetic system for functional manipulations of \u3ci\u3eFUM1,\u3c/i\u3e a polyketide synthase gene for the biosynthesis of fumonisins in \u3ci\u3eFusarium verticillioides\u3c/i\u3e

Fumonisins are mycotoxins produced by Fusarium verticillioides, a filamentous fungus that is a widespread pathogen of corn. The biosynthesis of fumonisins is catalyzed by an iterative modular polyketide synthase (PKS). The study of the biosynthetic mechanism for these reduced fungal polyketides has been challenging due to the difficulties in detecting the intermediates with a linear carbon chain and manipulating the 7-domain PKS gene from the filamentous fungus. Here, we described the development of a genetic system for functionally manipulating the methyltransferase domain of FUM1 that is responsible for the assembly of a dimethylated 18-carbon chain. Using a two-stage screening strategy, including both positive and negative screenings, we were able to generate mutant strains with a specifically changed active-site in FUM1. LC-MS analyses indicated that biosynthetic intermediates were detectable in the early stage of culture. The results represent the first functional manipulation of the PKS involved in the biosynthesis of fumonisins

Fumonisin level in corn-based food and feed from Linxian County, a high-risk area for esophageal cancer in China

The level of mycotoxin fumonisins in corn-based food and feed collected from Linxian County, a high-risk area for esophageal cancer in China, has been analyzed using high-performance liquid chromatographic coupled with evaporative laser scattering detector (HPLC-ELSD). A total of 104 corn kernel samples were obtained from local households, granaries, wholesale markets (central markets), and retail markets (stores and supermarkets). Fumonisin B1 (FB1) was detected in the samples from households, granaries, central markets, and stores, with a positive rate of 61.5%, 50%, 33.3%, and 17%, respectively. No fumonisin was detected in samples from the supermarket. The highest FB1 levels (0.30–3.20 μg/ g; mean, 1.42 μg/g) were found in samples from the granary, followed by household (0.25–1.80 μg/g; mean, 0.73 μg/g), central market (0.25–1.10 μg/g; mean, 0.51 μg/g), and store (0.22–0.34 μg/g; mean, 0.28 μg/g). Among the 80 corn kernel samples collected from local households, 18 of 24 (75.0%) moldy samples contained high levels of FB1 (0.28–3.30 μg/ g; mean, 1.58 μg/g), and 20 of 56 (35.7%) apparently healthy samples contained low levels of FB1 (0.21–0.82 μg/g; mean, 0.46 μg/g). As the central market plays an important role in trade of corn-based food and feed in China, a total of 115 cornbased food and feed samples were collected from the local central market. The highest FB1 levels (0.30–3.13 μg/g; mean, 1.50 μg/g) were found in feed, followed by unprocessed food (0.31–0.63 μg/g; mean, 0.47 μg/g) and processed food (0.21– 0.28 μg/g; mean, 0.25 μg/g). The positive incidence of FB1 in feed, unprocessed, and processed food were 53.6%, 33.3% and 17.9%, respectively. In conclusion, the results showed that corn-based food and feed from Linxian County contained low level of FB1 (\u3c2 μg/g) in general, but efforts should be made to control the fumonisin contamination in corn kernels stored in granaries and households

Functional replacement of the ketosynthase domain of \u3ci\u3eFUM1\u3c/i\u3e for the biosynthesis of fumonisins, a group of fungal reduced polyketides

The genetic manipulation of the biosynthesis of fungal reduced polyketides has been challenging due to the lack of knowledge on the biosynthetic mechanism, the difficulties in the detection of the acyclic, non-aromatic metabolites, and the complexity in genetically manipulating filamentous fungi. Fumonisins are a group of economically important mycotoxins that contaminate maize-based food and feed products worldwide. Fumonisins contain a linear dimethylated C18 chain that is synthesized by Fum1p, which is a single module polyketide synthase (PKS). Using a genetic system that allows the specific manipulation of PKS domains in filamentous fungus Fusarium verticillioides, we replaced the KS domain of fumonisin FUM1 with the KS domain of T-toxin PKS1 from Cochliobolus heterostrophus. Although PKS1 synthesizes different polyketides, the F. verticillioides strain carrying the chimeric PKS produced fumonisins. This represents the first successful domain swapping in PKSs for fungal reduced polyketides and suggests that KS domain alone may not be sufficient to control the product’s structure. To further test if the whole fumonisin PKS could be functionally replaced by a PKS that has a similar domain architecture, we replaced entire FUM1 with PKS1. This strain did not produce any fumonisin or new metabolites, suggesting that the intrinsic interactions between the intact PKS and downstream enzymes in the biosynthetic pathway may play a role in the control of fungal reduced polyketides

Introduction of the AAL-Toxin Polyketide Synthase Gene ALT1 into FUM1-disrupted Fusarium verticillioides Produces Metabolites with the Fumonisin Methylation Pattern

Fumonisins and AAL toxins are polyketide-derived mycotoxins produced by several important fungal pathogens of crop plants. The toxins contain a linear, dimethylated polyketide chain, but differ in chain length and methylation positions. Here, we have isolated the major metabolites from a fumonisin null mutant, Fusarium verticillioides strain 5777, that has been transformed with the AAL-toxin polyketide synthase gene (ALT1). The results showed that the metabolites maintained the chain length and methylation pattern of fumonisins. This suggests that the timing and regioselectivity of the methyltransferase of the ALT1 PKS could be reprogrammed in this Fusarium transformant.NSF [MCB-0614916]; NIH [RR015468-01

Introduction of the AAL-Toxin Polyketide Synthase Gene ALT1 into FUM1-disrupted Fusarium verticillioides Produces Metabolites with the Fumonisin Methylation Pattern

Fumonisins and AAL toxins are polyketide-derived mycotoxins produced by several important fungal pathogens of crop plants. The toxins contain a linear, dimethylated polyketide chain, but differ in chain length and methylation positions. Here, we have isolated the major metabolites from a fumonisin null mutant, Fusarium verticillioides strain 5777, that has been transformed with the AAL-toxin polyketide synthase gene (ALT1). The results showed that the metabolites maintained the chain length and methylation pattern of fumonisins. This suggests that the timing and regioselectivity of the methyltransferase of the ALT1 PKS could be reprogrammed in this Fusarium transformant.NSF [MCB-0614916]; NIH [RR015468-01