A chorismate mutase from Radopholus similis plays an essential role in pathogenicity

In the process of infecting plants, plant parasitic nematodes release a series of proteins that play an essential role in the successful infection and pathogenesis of plant cells and tissues through stylets or body walls. In this study,based on transcriptome data, a chorismate mutase gene of Radopholus similis(RsCM) was identified and cloned,which is a single copy gene specifically expressed in the oesophageal gland and highly expressed in juveniles and females. Transient expression of RsCM in tobacco leaves showed that it was localised in the cytoplasm and nucleus of tobacco leaf cells, which inhibited the pattern-triggered immunity(PTI) induced by flg22, including callose deposition and defence gene expression, and cell death induced by immune elicitors BAX, but could not inhibit cell death induced by immune elicitors Gpa2/RBP-1. The RNA interference(RNAi) transgenic tomato of RsCM obviously inhibited the infection, pathogenicity, and reproduction of R. similis. However, the resistance of the overexpression transgenic tomato of RsCM to R. similis infection was significantly reduced, and the expression levels of two salicylic acid(SA) pathway genes(PR1 and PR5) in roots infected by the nematode were significantly down-regulated,which indicated that RsCM might be involved in the inhibition of SA pathway. The results of this study demonstrate that RsCM suppresses the host immune system and might be a new target for the control of R. similis, which also provides new data for the function and mechanism of CM genes of migratory parasitic plant nematodes.

Impact of Winter Transit Air Masses on the Sources and Composition Characteristics of Atmospheric Pollution in Hengyang

Through the integration and analysis platform of particulate matter components,a preliminary comparison was conducted on the pollution contribution of the three winter transit air masses in December to environmental quality,and the changes and related relationships of water-soluble ions and particulate matter elements were analyzed.The results showed that winter transit air masses had a significant impact on the air quality in Hengyang.In the quantitative comparison of the primary pollutant contribution during the transit period of air masses,local sources and transit sources each accounted for half,and the impact of transit source on ambient air quality was much greater than that of seasonal base increase.Fine particulate matter was closely related to secondary ions,and particulate matter was closely related to primary ions.The transit of air masses promoted the improvement of secondary ion conversion rate,and the unit increment of fine particulate matter was greater than that of particulate matter.During the transit period,the mass concentrations of most water-soluble ions and most particulate matter elements maintained synchronous growth,with a superimposed effect.The composition ratio of organic carbon and nitrate ions increased,while the composition ratio of ammonia and sulfate ions decreased.Both disposable ions and secondary conversions in the composition of PM_(2.5)had increases and decreases.The high conversion rate of nitrate and the high composition ratio of ammonia radical in Hengyang indicated that transportation source factors had a significant impact on the local environmental quality of Hengyang.

Guidance Control for Parallel Parking Tasks

Parking into small berths remains difficult for unskilled drivers. Researchers had proposed different automatic parking systems to solve this problem. The first kind of strategies(called parking trajectory planning) designs a detailed reference trajectory that links the start and ending points of a special parking task and let the vehicle track this reference trajectory so as to park into the berth. The second kind of strategies(called guidance control) just characterizes several regimes of driving actions as well as the important switching points in certain rule style and let the vehicle follows the pre-selected series of actions so as to park into the berth. Parking guidance control is simpler than parking trajectory planning. However, no studies thoroughly validated parking guidance control before. In this paper, a new automatic parking method is presented, which could characterize the desired control actions directly. Then the feasibility is examined carefully. Tests show that a simple parking guidance control strategy can work in most parallel parking tasks, if the available parking berth is not too small. This finding helps to build more concise automatic parking systems that can efficiently guide human drivers.

Quantum metrology with coherent superposition of two different coded channels

We investigate the advantage of coherent superposition of two different coded channels in quantum metrology.In a continuous variable system,we show that the Heisenberg limit 1/N can be beaten by the coherent superposition without the help of indefinite causal order.And in parameter estimation,we demonstrate that the strategy with the coherent superposition can perform better than the strategy with quantum switch which can generate indefinite causal order.We analytically obtain the general form of estimation precision in terms of the quantum Fisher information and further prove that the nonlinear Hamiltonian can improve the estimation precision and make the measurement uncertainty scale as 1/N^(m) for m≥2.Our results can help to construct a high-precision measurement equipment,which can be applied to the detection of coupling strength and the test of time dilation and the modification of the canonical commutation relation.

Quantum estimation of detection efficiency with no-knowledge quantum feedback

We investigate that no-knowledge measurement-based feedback control is utilized to obtain the estimation precision of the detection efficiency. We show that no-knowledge measurement is the optimal way to estimate the detection efficiency.The higher precision can be achieved for the lower or larger detection efficiency. It is found that no-knowledge feedback can be used to cancel decoherence. No-knowledge feedback with a high detection efficiency can perform well in estimating frequency and detection efficiency parameters simultaneously; simultaneous estimation is better than independent estimation given by the same probes.

Application of Systematic Clustering Method in the Classification and Changes of Atmospheric Ozone in Hunan Province

The cluster analysis method needs continuous improvement and perfection in the research and application of the spatial differentiation and change of pollutants.In this paper,the date of monthly highest concentration of ozone(O_(3))and the concentration value of that day were selected as the similarity coefficient between classes.Single-factor cluster analysis was performed on O_(3)during 2016-2019 and the COVID-19 outbreak of 2020 in Hunan Province using the Ward method.The clustering results showed that the spatial distribution of atmospheric O_(3)in the 14 regions of Hunan Province was most suitable to be classified according to class III clustering areas.That is,the Changsha-Zhuzhou-Xiangtan urban agglomeration was the center,and the high-value area was in northern Hunan.The transition area was in central and southern Hunan,while the low-value area was centered in western Hunan.The partition results were in good agreement with the homogeneous subset of one-way ANOVA and the distribution of monitoring values during the same period.The comparison showed that the inter-class plates in the two periods corresponded well,and the intra-class area showed a continuous geographical distribution,and there were dynamic changes in the spatial differentiation of the O_(3)plates in different periods.In 2020,the center of the O_(3)high-value area plate in Hunan Province moved eastward and extended southward,focusing on the middle and lower reaches of the Xiangjiang River basin,and extending to the upstream area;the regional plate in the transition area expanded significantly;the low-value area plate shrank to the two cities in western Hunan.The abnormal emissions and abnormal climate during the COVID-19 epidemic had an impact on the spatial differentiation of O_(3)in Hunan Province.