Inhibiting Aspergillus flavus growth and degrading aflatoxin B1 by combined beneficial microbes

Aflatoxin B1 (AFB1) is a type of toxin produced by Aspergillus flavus, which has a negative effect on animal production and economic profits. In order to inhibit A. flavus growth and degrade aflatoxin, the optimal  proportion of beneficial microbes such as Lactobacillus casei, Bacillus subtilis and Pichia anomala were selected. The results show that AFB1 production and mycelium weight of A. flavus was decreased by more than 34 folds (161.05 vs. 4.69 µ/L) and 7.7 folds (6.98 vs. 0.90 mg/ml) with the free-cell supernatants of L. casei and B. subtilis (P<0.05), respectively. The optimal proportion of L. casei, B. subtilis and P. anomala was 2:1:2 for inhibiting A. flavus growth determined by 3x3 orthogonal design. Based on the optimal proportion of three microbial species, the maximum AFB1 degradation was during 24 to 48 h incubation (P<0.05). When three species of beneficial microbes were mixed with yeast cell wall and oligosaccharide, both of them could not help the microbes in AFB1 degradation. The combined microbial incubation showed that AFB1 contents in the supernatant and cells were 10.25 (P<0.05) and 3.34 µg/L, lower than the control group (68.55 µg/L), indicating that most of the AFB1 were degraded by the microbes and only a little of them were absorbed and deposited in microbial cells.Key words: Aspergillus flavus, aflatoxin B1 detoxification, beneficial microbes, yeast cell wall, oligosaccharide

Breaking Immutable: Information-Coupled Prototype Elaboration for Few-Shot Object Detection

Few-shot object detection, expecting detectors to detect novel classes with a few instances, has made conspicuous progress. However, the prototypes extracted by existing meta-learning based methods still suffer from insufficient representative information and lack awareness of query images, which cannot be adaptively tailored to different query images. Firstly, only the support images are involved for extracting prototypes, resulting in scarce perceptual information of query images. Secondly, all pixels of all support images are treated equally when aggregating features into prototype vectors, thus the salient objects are overwhelmed by the cluttered background. In this paper, we propose an Information-Coupled Prototype Elaboration (ICPE) method to generate specific and representative prototypes for each query image. Concretely, a conditional information coupling module is introduced to couple information from the query branch to the support branch, strengthening the query-perceptual information in support features. Besides, we design a prototype dynamic aggregation module that dynamically adjusts intra-image and inter-image aggregation weights to highlight the salient information useful for detecting query images. Experimental results on both Pascal VOC and MS COCO demonstrate that our method achieves state-of-the-art performance in almost all settings.Comment: Accepted by AAAI202

Fibre Bragg gratings fabrication in four core fibres

Due to the limitation of the lens effect of the optical fibre and the inhomogeneity of the laser fluence on different cores, it is still challenging to controllably inscribe different fibre Bragg gratings (FBGs) in multicore fibres. In this article, we reported the FBG inscription in four core fibres (FCFs), whose cores are arranged in the corners of a square lattice. By investigating the influence of different inscription conditions during inscription, different results, such as simultaneous inscription of all cores, selectively inscription of individual or two cores, and even double scanning in perpendicular core couples by diagonal, are achieved. The phase mask scanning method, consisting of a 244nm Argon-ion frequencydoubled laser, air-bearing linear transfer stage and cylindrical lens and mirror setup, is used to precisely control the grating inscription in FCFs. The influence of three factors is systematically investigated to overcome the limitations, and they are the defocusing length between the cylindrical lens and the bare fibre, the rotation geometry of the fibre to the irritation beam, and the relative position of the fibre in the vertical direction of the laser beam