Background Mosquitoes are vectors of many tropical diseases. Understanding the ecology of local mosquito vectors, such as species composition, distributions, population dynamics, and species diversity is important for designing the optimal strategy to control the mosquito-borne diseases. Methods Entomological surveillance of adult mosquitoes was conducted in five sites representing different ecological settings across Hainan Island from January to December of 2018 using BG Sentinel (BGS) traps and Centers for Disease Prevention and Control (CDC) light traps. In each site, we selected three areas representing urban, suburban and rural settings. Eighteen trap-days were sampled in each setting at each site, and CDC light traps and BGS traps were setup simultaneously. Mosquito species composition, distribution, population dynamics, and species diversity were analyzed. Mosquito densities were compared between different study sites and between different settings. Results Nine species of mosquitoes belonging to four genera were identified. Culex quinquefasciatus (80.8%), Armigeres subalbatus (13.0%) and Anopheles sinensis (3.1%) were the top three species collected by CDC light traps; Cx. quinquefasciatus (91.9%), Ae. albopictus (5.1%), and Ar. subalbatus (2.8%) were the top three species collected by BGS traps. Predominant species varied among study sites. The population dynamics of Ae. albopictus , An. sinensis and Cx. quinquefasciatus showed clear seasonal variation regardless of study sites with a varied peak season for different species. Mosquito abundance of all species showed significant differences among different study sites and among urban, suburban and rural areas. Danzhou had the highest mosquito biodiversity, with an α, β, and Gini-Simpson biodiversity index of 8, 1.13 and 0.42, respectively. BGS traps captured Aedes mosquito at a higher efficiency than CDC light traps, whereas CDC light traps captured significantly more Anopheles and Armigeres mosquitoes than BGS traps. Conclusions Mosquitoes were abundant on Hainan Island with clear seasonality and spatial heterogeneity. Population density, species composition, distribution, and species diversity were strongly affected by the natural environment. Different tools are required for the surveillance of different mosquito species.

OBJECTIVE To develop a trivalent genetically engineered inactivated Escherichia coli vaccine (K88ac-3STa-LTB) that neutralizes the STa toxin by targeting fimbriae and entertoxins for the treatment of enterotoxigenic E coli. ANIMALS 18- to 22-g mice, rabbits, pregnant sows. PROCEDURES Using PCR, the K88ac gene and LTB gene were cloned separately from the template C83902 plasmid. At the same time, the 3 STa mutant genes were also amplified by using the gene-directed mutation technology. Immune protection experiments were performed, and the minimum immune dose was determined in mice and pregnant sows. RESULTS The ELISA test could be recognized by the STa, LTB, and K88ac antibodies. Intragastric administration in the suckling mouse confirmed that the protein had lost the toxicity of the natural STa enterotoxin. The results of the immune experiments showed that K88ac-3STa-LTB protein could stimulate rabbits to produce serum antibodies and neutralize the toxicity of natural STa enterotoxin. The efficacy test of the K88ac-3STa-LTB-inactivated vaccine showed that the immune protection rate of the newborn piglets could reach 85% on the first day after suckling. At the same time, it was determined that the minimum immunization doses for mice and pregnant sows were 0.2 and 2.5 mL, respectively. CLINICAL RELEVANCE This research indicates that the K88ac-3STa-LTB trivalent genetically engineered inactivated vaccine provides a broad immune spectrum for E coli diarrhea in newborn piglets and prepares a new genetically engineered vaccine candidate strain for prevention of E coli diarrhea in piglets.

With the rapid development of modern technology, virtual reality technology is also used in our lives. This article discusses the virtual reality technology to simulate the English teaching courses for students majoring in occupational health in higher vocational schools. Virtual reality technology is a new technology derived with informatization. It is a process of building a virtual environment to make people feel the five senses. In English teaching, building a direct English environment is the best way to learn English. For non-native English students, constructing a real English language environment can make English teaching more effective. Through the introduction of virtual reality technology, this paper explores the possibility of using virtual reality technology in English teaching, using constructivism to construct a real language environment, allowing learners to truly experience the native English environment, increasing their interest in learning, and improving teaching effects. Aiming at the boring characteristics of the English learning process, based on virtual reality technology, an English learning education system is designed to encourage teachers to use interactive, graphical, game-like examples to teach and motivate students to use words and sentences It also promotes students’learning and understanding of the course through game teaching. This article conducts research on the performance and interest of students in English teaching by studying the English teaching courses of students majoring in virtual reality technology in health. Virtual reality technology is penetrating into various fields of daily life at an unprecedented speed. The combination with various disciplines is becoming more extensive and deeper. For traditional English linguistics and related disciplines, the huge impact of virtual reality technology is self-evident, but it also expands the research space for traditional system functional linguistics and pragmatics.

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In order to develop the K88ac-3STa-LT2 trivalent genetically engineered inactivated vaccine, the recombinant strain BL21(DE3)(pXK88ac3STaLT2) was constructed. ELISA test showed that the K88ac-3STa-LT2 fusion protein could be recognized by STa monoclonal antibody, LT2 and K88ac antibody. The test of intragastric administration in the suckling mouse confirmed that the expressed fusion protein had lost the toxicity of the natural STa enterotoxin. The results of immune experiments showed that K88ac-3STa-LT2 fusion protein could induce rabbits to produce serum antibodies, which had the effect of neutralizing the toxicity of natural STa enterotoxin. Efficacy test of the K88ac-3STa-LT2 genetically engineered inactivated vaccine showed that the immune protection rate of the newborn piglets could reach 85% on the 1st day after suckling. At the same time, it was determined that the minimum immunization doses for mice and pregnant sows were 0.2 mL and 2.5mL respectively. This study provided scientific parameters for the industrialized production of the vaccine and showed that the K88ac-3STa-LT2 trivalent genetically engineered inactivated vaccine had a broad immune spectrum for E. coli diarrhea in newborn piglets. Through this research, a new genetic engineering vaccine candidate strain was provided for more effective prevention of E. coli diarrhea in piglets.

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