In order to explore the roles of intestinal microbiota in lipid metabolism of aquatic animals and improve the ability of aquatic animals to utilize dietary vegetable oils in compound feeds, this study collected the intestinal contents of juvenile golden pompano (Trachinotus ovatus) fed diets with soybean oils or linseed oils, and then isolated a strain of Vibrio alginolyticus TO1 which can absorb linoleic acid and linolenic acid through adding Nile red dye and mixed fatty acid substrates to the culture mediums. Moreover, a strain of Vibrio harveyi TO1, which can produce high-yield lipase and degrade soybean oils and linseed oils, was also isolated by adding an indicator of bromocresol purple in the liquid mediums and a hydrolysis circle observed in the solid medium with tributyrin. These results indicate that the intestinal microbiota of fish can respond to the lipid sources of compound feeds fed to fish. When the dietary lipid source of fish oils was replaced with vegetable oils, the abundance of Vibrio in intestine will increase, which absorbs, degrades and utilizes vegetable oils, and then participate in lipid metabolism in fish.

Bacteria pathogens were isolated from brain tissue of diseased American bullfrog (Lithobates catesbeiana) cultured in farms of Guangdong provinces. One bacteria strain with strong virulence was chosen for identifications. The morphological, biochemical and physiological characteristics, phylogenetic analysis of the isolate was achieved by using conventional method, BD PhoenixTM M50 Automated Microbiology System, 16S rDNA and gyrB genes sequence analysis, the characteristics of the isolated strain were in accordance with those of Elizabethkingia miricola. The virulent tests were carried out by using the pure culture of the isolated strain artificially infected American bullfrog with the concentration of 1×10^8 CFU·mL -1, the result indicated that the isolated strain could infected and caused the same typical wry head symptom as nature infected frog. The morphological and biochemical characteristics of the re-isolated bacteria from the artificially infected diseased frog were the same as those of the original infected bacteria. Antibiotic sensitivity assays showed that among 19 antibiotics tested 4 were sensitive, 8 were tolerant. This experiment successfully isolated a single strain of Elizabethkingia miricola, which provided a scientific basis for the prevention and treatment of American bullfrog infected with Elizabethkingia miricola.

In order to understand the effects of female body weight of giant freshwater prawn (Macrobrachium rosenbergii) on their reproductive performance and embryo quality, the reproductive performance, embryo quality, and egg colouration of four sizes of female M. rosenbergii broodstock (A: 16-20 g/tail, B: 24-28 g/tail, C: 32-36 g/tail, D: 40-44 g/tail) were compared in this study, and the correlation between body weight and reproductive performance was also analyzed. The results showed that while the body weight of giant freshwater prawn broodstock increased, the amount of egg production increased significantly. The egg production of group D was significantly higher than that of group A, B and C, while that of group C was significantly higher than that of group A. The reproduction and reproductive index also increased with the increase of body weight, with group D significantly higher than group A. However, there was no significant difference among groups A, B and C, and among groups B, C and D. There was no significant difference in wet weight, dry weight and diameter of single egg among the groups, as well as the embryo color parameters. The body weight of giant freshwater prawn broodstock exhibited significant positive correlation with egg production (r=0.847,P=0.000), fecundity (r=0.508,P=0.004), and reproductive effort (r=0.551,P=0.001). In conclusion, the reproductive performance of larger size of giant freshwater prawn broodstock was better than that of smaller size, but the size had no obvious influence on embryo quality. These results could provide valuable information for the broodstock selection, evaluation of reproductive performance and artificial breeding of giant freshwater prawn in the future.

In order to analyze the molecular phylogenetic relationships of Scolopsis fish in China sea as well as investigate the applicability of COⅠ gene as a DNA barcode for the Scolopsis species identification, partial sequences of COⅠ genes of 9 Scolopsis species were amplified and sequenced, in this study. Combining with 5 COⅠ sequences obtained from GenBank, the molecular phylogenetic relationships of 14 Scolopsis species were constructed and analyzed. The results indicated that: the average intra-species genetic distance values of 14 Scolopsis species was 0.002 5, while the average inter-species genetic distance value was 0.179 4, which was 71.76 times of the former. In the molecular phylogenetic tree, 14 species mainly formed three groups. Group Ⅰ included 4 Scolopsis species, that had big sharp bone below the eyes, which was consistent with morphological classification; Group Ⅱ included 4 species and the Group Ⅲ included 6 species, however the noding support values were relatively low in some branches, indicating that COⅠ gene can be used as an effective DNA barcode gene to distinguish species, but may not suitable for molecular phylogenetic analysis. In addition, the COⅠ genetic distance values of certain species which under morphological synonyms argument (Scolopsis taenioptera+Scolopsis bimaculata,+ Scolopsis monogramma and Scolopsis affinis + Scolopsis aurata) were revealed to be 0.160, 0.118, and 0.122, respectively. The values were all far greator than the minimum distance value (2%) in distinguishing different species recommended by Hebert, suggesting that they should be independent species.

The protection of ancient tree reserve resources is one of the important indicators of building a national and provincial garden city, which is of great significance to ecological protection and environmental beautification. Based on the field investigation in Shanwei City, this paper analyzes the composition structure, morphological characteristics, important value and spatial distribution of the existing ancient tree reserve resources. The results showed that there were 97 ancient tree reserve resources (belonging to 10 families, 12 genera and 13 species), all of which were native tree species in Guangdong, and Moraceae Ficus microcarpa L. F. is the dominant species, accounting for 80.41% of the ancient tree reserve resources. In terms of spatial distribution, reserve resources are mainly concentrated at the intersection of 115.34~115.37 °E and 22.79~22.80 °N, and there is no significant difference in the distribution of quantity and species in longitude and latitude. Based on the investigation and analysis results, it is considered that the reserve resources should focus on protecting and expanding the tree species with low base, and balance the number of reserve resources in various regions, so as to alleviate the risk of ancient tree de listing.

In order to improve the use efficiency of Avermectins and avoid the photodegradation of AVM, the hexagonal boron nitride exfoliated by ultrasonication was modified via hydrothermal method with octadecylamine (ODA) and polyethylene glycol diglycidyl ether (PEGDGE). The effects of pH value, feed ratio and hydrothermal reaction temperature on the aqueous dispersion stability of functionalized h-BN were investigated. The results showed that: when the pH value was 1, the feed ratio was 1∶2∶8∶24, and the reaction temperature was 60℃, the BNNS-PEGDGE-ODA carrier with the best aqueous dispersion stability was achieved. The functionalized boron nitride carrier was applied to load the pesticide (i.e.avermectin), and the loading capacity reached 158.65 mg·g-1. The cumulative release rate of avermectin was only 22.34% at pH 9 after 480 h and the residual amount was still 47.62% after exposing to UV irradiation for 190 min. The existence of BNNS-PEGDGE-ODA carrier is a potential candidate for environmentally friendly pesticide carriers with controlled release ability and UV stability.

First, a spline quasi-interpolation method based on isometric nodes had been constructed, which had constant reproducibility. Then it was applied to calculate definite integrals and a new type of numerical integration method had been obtained. Numerical experiments showed that: this numerical integration method had higher precision and faster convergent rate.

Hausdorff metric on the intuitionistic fuzzy metric space was defined and the definition of F-contraction was generalized to the mapping in intuitionistic fuzzy metric space. On this basis, the common fixed point theorems for single-valued mappings and the existence of fixed points for multi-valued mappings in intuitionistic fuzzy metric spaces was studied. In this way, the fixed point theorem of single-valued mapping could be extended to the fixed point theorem of multi-valued mapping in this space.

Guangzhou is a mega city with a population of over 10 million, and there is a huge demand for agricultural products logistics. The SWOT analysis method was used to analyze the overall development of Guangzhou's agricultural products logistics from four aspects: internal strengths, internal weaknesses, external opportunities, and external threats. The PEST analysis method was embedded into the SWOT analysis method to analyze each aspect from the perspectives of politics, economy, society, and technology, and the SWOT-PEST analysis matrix for the development of agricultural products logistics in Guangzhou was constructed. Finally, the development strategies of agricultural products logistics in Guangzhou were proposed from four perspectives:strengths-opportunities, weaknesses-opportunities, strengths-threats and weaknesses-threats.

Phascolosoma arcuatum belongs to the family Phascolosomatiformes, which is rich in nutrition and has a good prospect of development. In order to provide theoretical support for the large-scale culture, in-depth development and utilization of Phascolosoma arcuatum, the biological characteristics, cultural techniques, nutritional components and biological efficacy of Phascolosoma arcuatum were summarized in this paper.

Silicone gel is a network of polydimethylsiloxane single chains linked by vinyl bridge and long chains entwined with each other.The protective film formed on the surface of the scar after drying has good air permeability and heat dissipation, which greatly reduces the risk of infection caused by dampness of the scar.In this paper, the clinical cases of silica gel and the combined therapy of it for the treatment of scar are described, the current mechanism of prevention and treatment of scar by silica gel is summarized, and the application direction of silica gel for the treatment of scar in the future is put forward.