Reproductive characteristics of Artemisia scoparia and the analysis of the underlying soil drivers in a desert steppe of China
Chinese Journal of Plant Ecology,2019,Vol 43,No. 01
【Abstract】 Aims Reproduction is an important part of plant life activities, and thus the reproductive characteristics of plants play an important role in explaining the ecological adaptability of plants as well as developing effective management strategy plans. The aims of this study are to explore the reproductive characteristics of Artemisia scoparia and analyze its main soil driving factors in a desert steppe of China. Methods As a method to extract and summarize the variation in a set of response variables, the redundancy analysis can be explained by a group of explanatory variables. In the present study, we selected the A. scoparia population in a desert steppe, and examined the physicochemical properties of different soil types and reproductive characteristics of A. scoparia with the redundancy analysis. Important findings There were significant differences in water-soluble carbon content ( Cws), total nitrogen content ( TN), total phosphorus content ( TP), total salt content ( TS), soil moisture ( Ms) and soil hardness ( SH) of calcareous soil (SS), aeolian sand soil (ASS) and weathered residual soil (WB). The average mass ( Ma), the number ( Ni) of average individual head inflorescence, and the average individual size ( Sai) of a single plant were the largest in the SS habitat, followed by ASS and WB. No significant difference was observed in the reproductive allocation ( Ra) of A.scoparia in different soil types. Extremely significant positive correlation was observed between Ra and the quality of single capitate inflorescence ( Me), Ni and Ma, respectively, while Ni was negatively correlated with Me. The variation of the reproductive characteristics of A. scoparia was mainly affected by the soil water soluble carbon content ( Cws), soil hardness (SH), soil moisture ( Ms), TP and available phosphorus content ( AP) in WB habitat. Ma was mainly affected by Cws, Ms and pH value; Ni was mainly affected by total salt content ( TS); Ra and Me were mainly affected by the total carbon content ( Ct) in the ASS habitat. Ma was positively correlated with Cws, Ms and Co, while the correlation between Ma and Co was not significant; Ni was significantly affected by the available nitrogen content ( AN) in the SS habitat. A comprehensive analysis of the three soil types showed that the total explanatory amount of soil factors affecting the reproductive characteristics of A.scoparia was 30.74%. Ma and Ni were significantly affected by Cws and Ms. Ra and Me were negatively correlated with Cws and Ms though they were not statistically significant. We conclude that Cws and Ms are the main soil factors affecting the reproductive characteristics of A. scoparia populations in the desert grassland.
The determinants of pig scale production and its spatial correlation: an analysis based on data from 13 main provincial-level regions of pig production in China
Chinese Rural Economy,2019,No. 01
【Abstract】 Based on relevant statistics from 2007 to 2015, this paper described the development course and the scale production characteristics of pig production by using the scale index of 13 provincial-level regions. Afterwards, it established a spatial model to analyze the determinants of pig scale production and its spatial correlation. The main conclusions were as follows. Firstly, pig scale production in China tended to concentrate in north China and northeast China, and the pig production scale was generally low. Secondly, there were several factors influencing pig scale production, including farmers’ educational level, urbanization level, non-agricultural employment wage rate, pork consumption capacity, pork price index, traffic accessibility, output of pig production and environmental regulation intensity. Thirdly, pig scale production had spatial dependence on the determinants such as land carrying capacity, urbanization level, non-agricultural employment wage rate, potential consumer market, pork consumption capacity, traffic accessibility, farmers’ ability to invest in fixed assets and environmental regulation intensity. Therefore, in the process of promoting pig scale production, the government should fully consider the spatial correlation and spillover effects. On one hand, we should expand the potential consumer market, improve the pork consumption capacity and transportation accessibility, enhance farmers’ ability to invest in fixed assets, and strengthen environmental regulation. On the other hand, we should also consider the inhibiting effect of the urbanization level and land carrying capacity.
Chinese Journal of Virology,2019,Vol 35,No. 04
【Abstract】 Epitope-based vaccines of neutralizing antibody are more accurate and efficient than traditional vaccines, and can induce strong antibody reaction. We wished to identify a monoclonal neutralizing antibody epitope of the porcine epidemic diarrhea virus and develop a new vaccine based on this neutralizing epitope. Phage display was used to identify the epitopes of two neutralizing antibodies 2B11 and 2G8 screened by our research team. The antigenicity of the screened amino-acid sequences was evaluated. Eight short peptides with high affinity for the target monoclonal antibody were identified, and all phages containing the short peptides could bind specifically to the neutralizing antibody, thereby reducing the neutralizing effect of the antibody. This peptide sequence, coupled with BSA, was synthesized artificially and immunized in BALB/c mice. One peptide sequence was found to induce the body to produce neutralizing antibodies with a titer of 1:10. These data suggest that mice can be induced to produce neutralizing antibodies by immunization them with BSA coupled with the antigen epitope.