Integrated analysis reveals an association between the rhizosphere microbiome and root rot of arecanut palm

The rhizosphere microbial community is crucial to plant health. Many studies have explored the association between the rhizosphere microbiome and plant disease. However, few studies have focused on root rot in arecanut palm, a disease causing devastating effects and thus resulting in economic losses that considerably affect the development of the arecanut industry. Here, rhizosphere samples were collected from both healthy arecanut palm plants and root-rotted arecanut palm plants, and the microbial communities were analyzed using high-throughput sequencing. The root-rotted samples exhibited distinct microbial community richness, diversity, and composition compared with the healthy samples, which was associated with pH according to the Mantel test. Identified potential plant pathogens, including Proteobacteria, Bacteroidetes, Chytridiomycota, and Mortierellomycota, were significantly enriched in the root-rotted samples. In contrast, potentially beneficial plant microbes, such as Acidobacteria and Gemmatimonadetes, were significantly depleted in the root-rotted samples. Co-occurrence networks were constructed to further identify microbial relationships in the root-rotted samples. These findings revealed ecological imbalance among beneficial bacteria in the root-rotted samples. The present study therefore provides an integrated view of the association between the microbial community and root rot in arecanut palm.     

Zokor activity promotes soil water infiltration in the Mu Us sandy land of northern Shaanxi, China

Zokors are common subterranean rodents that inhabit agricultural fields, shrublands, and grasslands in the arid and semi-arid regions of China. Zokor burrowing activities can alter soil structure and affect soil hydrological processes; however, there are few studies regarding their effects on soil preferential flow in the Mu Us sandy land. An evaluation of the effects of zokor disturbance on their habitat and soil water is important for understanding the ecological role of zokors in the soil eco...     

A FIASCO-Based Approach for Detection and Diagnosis of Puccinia graminis f. sp. tritici in China

Stem or black rust of wheat, caused by the fungus Puccinia graminis Pers. f. sp. tritici Eriks.＆E. Henn. （Pgt）, has historically caused severe losses to wheat （Triticum aestivum L.） production worldwide. In the Fujian and Guangdong provinces of China, six moderate-to-severe epidemics of wheat stem rust have occurred, which caused destructive losses of wheat between 1949 and 1966, although these were brought under control by integrated management. A rapid and reliable detection of the pathogen will contribute to the accurate forecast and seasonal control of this disease. The objective of this study was to develop a diagnostic molecular marker generated from simple sequence repeats （SSR） for the early rapid identiifcation of P. graminis. The genomic DNA of P. graminis, Puccinia striiformis, Puccinia triticina and seven other species was ampliifed by a pair of SSR primers generated by the FIASCO （fast isolation by AFLP sequences containing repeats） enrichment protocol. The primer set Pgtw （f）/Pgtw （r） generated a polymorphic pattern displaying a 330-bp DNA fragment speciifc for P. graminis whereas no DNA fragment was obtained from other non-target wheat fungal pathogens. The detection limit of the primer was 1 ng DNA in a 25-mL PCR reaction. The SSR markers of P. graminis can also be used to detect the presence of latent hyphae in Pgt-infected wheat leaves as early as 30 h post-inoculation. A rapid approach to distinguish P. graminis from similar pathogenic fungi would be anticipated in further study.     

Analysis on Efficiency and Fairness of Individual Income Tax

The relationship between efficiency and fairness of individual income tax is analyzed to get to know which one should be the first. By empirically researching on individual income tax and GD Pand analyzing on economic distributive rate and social unfair cost, the anthors conclude that efficiency of individual tax becomes weak and unfairness of it becomes strong. Thus, individual income tax should be reformed more fairly.     

Discussion about the Landscape-superposition by Means of Isomorph-accumulation on Mountainous Landform

Based on the system science and by analyzing the landscape of "qian hu miao zhai" in Guizhou Province and a landscape project along Jialingjiang River in Chongqing, in this paper, to seek a design method for mountainous city landscape is investigated by creation of landscape-superposition through isomorph-accumulating on mountainous landform in order to provide a new approach for the design of distinctive landscape in mountainous cities.     

副干酪乳杆菌固态发酵枣粉工艺优化及其品质分析

为制得一种活菌数高且稳定性较好的红枣益生菌粉,以红枣为主料,副干酪乳杆菌(Lactobacillus paracasei)TK1501为发酵菌株进行固态发酵,通过单因素试验和响应面试验优化发酵工艺。基于优化后的工艺制作红枣益生菌粉,对其理化指标、微生物安全性进行检测,并开展综合评价。结果表明,最佳发酵工艺为料水比1∶0.9、豆粉添加量24%、麦麸添加量9%、接种量10%、发酵时间24 h,最佳干燥方式为-50 ℃冷冻干燥24 h。在此条件下制备的样品,活菌数含量为7.21×10⁸ CFU·g^-1,粗多糖、乳酸、苹果酸、柠檬酸、游离氨基酸、γ-氨基丁酸含量较发酵前提高,且口感酸甜,枣香浓郁,综合评价良好,各项理化指标和微生物安全指标均符合相应标准,在(37±2)℃的条件下贮藏90 d,样品基本保持稳定。     

Parameter Design for Machining Quenched Internal Helical Gears by EDM

Aiming at the problem of machining quenched internal helical gears, a method and its equipment are discussed and designed, which is used for machining quenched internal helical gears by EDM. Its characteristic and principle are proposed. The modifying design of the electrode gear and the calculating method of its modification coefficients is presented. Analyzing for the error of the machining equipment is done. The results show that this problem can be solved by EDM, the electrode gear is the modification gear of machined gear and the machining accuracy can be improved by controlling errors.     

Leak Current Fault Diagnosis Problem-Solving in Launch Vihicle Controlling System

In point of view of the system, the characteristic of leak current fault diagnosis in launch vehicle controlling system is analyzed. It is presented that the fault is a connecting way for sytem factors. By building some basic concepts such as componts, syptoms, observation and faults, the system model is turned into graph, where nodes represent components and edges represent fault transmission among components. Besides,designing rule, that is, bisection rule for diagnosing alglorithm is given based on the information theory. Operating feasibility and entropy function characteristic are analyzed using component trade-off value to substitute component entropy, giving fault problem-solving way based on the drawing model.     

Analyse of Compressor Sound Quality

By of Stevens steady wide frequency noise loudness and Fastl total sensation noise calculation method, sound quality evaluation of the noise left and back-end face was studied before the compressor improved and after the minipore muffler installed. The research indicates that the compressor noise is reduced, at the same time, the loudness left the compressor and the back - end face is reduced by 10.25 sone and 13.3 sone respectively. The rate reduced is over 40%. The total sensation noise is reduced by 12.5 noy and 15 noy, the rate achieved is over 45%. It is very perfect to improve the compressor sound quality with the use of minipore muffler.     

Effects of Fines Content on Evolutionary Characteristics of Dynamic Pore Water Pressure of Saturated Sands

With the GDS dynamic triaxial system, undrained dynamic triaxial tests on the saturated sand with different fines content are performed, and the effects of fines content on evolutionary characteristics of dynamic pore water pressure of saturated sands in the process of liquefaction are analyzed based on Seed pore water pressure stress model. It is found that fines content has great effect on the dynamic pore water pressure of saturated sands by the parameter θ for Seed model. The relationship between parameter θ and fines content isnt linear. Parameter θ decreases with the increase of fines content at first, and then reaches its smallest value when the critical value of fines content is 30%. After that, parameter θ increases gradually with the rise of fines content. According to the experimental study on effects of fines content on evolutionary characteristics of dynamic pore water pressure of saturated sands, the existence of critical fines content with 30% is further proved in the sandy soil used in the test.