MR-FPN: Multi-Level Residual Feature Pyramid Text Detection Network Based on Self-Attention Environment.

With humanity entering the age of intelligence, text detection technology has been gradually applied in the industry. However, text detection in a complex background is still a challenging problem for researchers to overcome. Most of the current algorithms are not robust enough to locate text regions, and the problem of the misdetection of adjacent text instances still exists. In order to solve the above problems, this paper proposes a multi-level residual feature pyramid network (MR-FPN) based on a self-attention environment, which can accurately separate adjacent text instances. Specifically, the framework uses ResNet50 as the backbone network, which is improved on the feature pyramid network (FPN). A self-attention module (SAM) is introduced to capture pixel-level relations, increase context connection, and obtain efficient features. At the same time, the multi-scale enhancement module (MEM) improves the expression ability of text information, extracting strong semantic information and integrating the multi-scale features generated by the feature pyramid. In addition, information regarding the upper features will cause loss when the feature pyramid is passed down step by step, and multi-level residuals can effectively solve this problem. The proposed model can effectively improve the fusion ability of the feature pyramid, provide more refined features for text detection, and improve the robustness of text detection. This model was evaluated on CTW1500, Total-Text, ICDAR2015, and MSRA-TD500 datasets of different kinds and achieved varying degrees of improvement. It is worth mentioning that the F-measure of 83.31% obtained by this paper on the Total-Text dataset exceeds that of the baseline system by 5%.

Effects of pulse parameters on the temperature distribution of a human head exposed to the electromagnetic pulse.

The presence of blood-brain barrier (BBB) is a major obstacle to effectively deliver therapeutics to the central nervous system (CNS); hence, the outcomes following treatment of CNS diseases remain unsatisfactory. Fortunately, electromagnetic pulses (EMPs) provide a non-invasive method to locally open the BBB. To obtain the optimal pulse parameters of EMP-induced BBB opening to ensure the effective delivery of CNS drugs, it is particularly important to measure and assess the effects of pulse parameters on the temperature distribution in the human head exposed to EMPs. In this paper, the specific anthropomorphic mannequin phantom was adopted and the temperature increase in the human head induced by EMPs of different parameters was estimated in the software "COMSOL Multiphysics". The results show that the temperature distribution profiles with different EMP parameters have almost similar characteristics, the highest temperature increase values in the human head are positively correlated with variations of EMP parameters, and potential hazards to the human head may occur when EMP parameters exceed the safety threshold, which will provide theoretical basis for seeking the optimal EMP parameters to open the BBB to the greatest extent within a safe range.

Remediation of blowouts by clonal plants in Maqu degraded alpine grasslands of northwest China.

The sand-fixation of plants is considered to be the most effective and fundamental measure in desertification control in many arid and semi-arid regions. Carex brunnescens (Carex spp) and Leymus secalinus (Leymus), two perennial clonal herbs native to the Maqu degraded alpine areas of northwest China, are dominant and constructive species in active sand dunes that have excellent adaptability to fix sand dunes found to date. In order to study the ability and mechanism of sandland blowout remediation by two clone plants C. brunnescens and L. secalinus, the artificially emulated blowouts were set up in the populations of two clonal plants in the field. The results showed that both C. brunnescens and L. secalinus produced more new ramets in the artificially emulated blowouts than in the natural conditions, suggesting that the two clonal plants had strong ability in blowouts remediation; while the biomass, number of leaves and height of new ramets in the artificially emulated blowouts were less than in the natural conditions due to the restriction of poor nutrients in the artificially emulated blowouts. The ability of blowouts remediation by C. brunnescens was stronger than L. secalinus, as it generated more new ramets than L. secalinus in the process of blowouts remediation. The new ramets of L. secalinus in the blowouts remediation were mainly generated by the buds in the rhizomes which spread from outside of the blowouts; while those of C. brunnescens were generated both by the buds in the rhizomes which spread from outside, and by the buds in the rhizomes inside which were freed from dormancy in the deeper soil under wind erosion conditions. These findings suggest that through rapid clonal expansion capability, C. brunnescens and L. secalinus exhibited strong ability in blowouts remediation which can be one of the most effective strategies to restore and reconstruct degraded vegetations in Maqu alpine areas of northwest China.

Silicon improves photosynthesis and strengthens enzyme activities in the C3 succulent xerophyte Zygophyllum xanthoxylum under drought stress.

One main strategic adaptive mechanism adopted by succulent xerophyte species, resistance to drought stress is absorbing and accumulating large amounts of sodium (Na+) from poor and dry soil which was stored in photosynthesizing branches as well as leaves as major osmoregulators, while still accumulating and storing a great deal of silicon (Si) in roots to resist to arid environments. To understand the possible adaptive strategies underlying how Si accumulation stimulates growth and ameliorates the adverse environmental impacts of drought stress on the C3 succulent xerophyte Zygophyllum xanthoxylum, plants grown for 3 weeks were suffered different K2SiO3 concentrations (1.5-7.5mM) (3-15mM KCl as control) treatments in sand culture experiments. Plants were also treated with different osmotic stresses caused by polyethylene glycol (PEG 6000) and drought stress (maintain water content about 30% of field water capacity) (30% of FWC) with or without additional 2.5mMK2SiO3 (5mMKCl as control) treatment in sand culture and pot experiments, respectively. We found that 2.5mMK2SiO3 (5mMKCl as control) resulted in optimal plant growth and alleviated adverse influences of drought stress on Z. xanthoxylum, by strengthening the activities of superoxide dismutase, peroxidase and catalase, reducing membrane lipid peroxidation and decreasing soluble sugar and free proline concentrations, concomitantly, increasing tissue water content, leaf area and chlorophyll a concentration. The result of ion analysis indicated that the Si absorption of Z. xanthoxylum was markedly induced by drought stress and that the 2.5mMK2SiO3 (5mMKCl as control) treatment significantly increased the aboveground and root Si concentration under different osmotic stresses and 30% of field water capacity compared with the drought and drought with 5mMKCl treatments. Although the K+ concentration in root in the drought with 2.5mMK2SiO3 treatment was no significant changes compared with the drought treatment, K+ concentration in aboveground and root in drought with 2.5mMK2SiO3 treatment were significantly decreased by 42% and 65.2% compared with drought with 5mMKCl treatment under 30% of FWC, indicating that Si replaced the function of K+, thus stimulating the growth and mitigating adverse effects of Z. xanthoxylum under water deficit. These findings showed that the positive roles of Si in the drought tolerance of Z. xanthoxylum might be due to the ability of plant to accumulate a great quantity of Si and utilize it as an osmoregulator to copy with water deficit, which was coupled with an obvious improvement in photosynthetic activity and anti-oxidative enzyme activities.