Search

The Maritime Power strategy is of great and far-reaching significance for the high-quality development of China. With the development of this strategy in recent years, academics and the government have been increasingly focusing on marine and national defense issues. It is of great theoretical value and practical significance to clarify the destination images of China's marine national defense tourism and its mode of communication to enhance tourists' national identity. Using data from 15 marine national defense tourist attractions, this study analyzes the official projections and tourist perceptions of marine national defense tourism in China. Key elements were identified using social semantic network and image depth analyses. The Jaccard distance score and Stuart Hall's encoding and decoding theory were applied to explore the internal differences in projections and perceptions in different regions and propagation modes. The results are as follows: (1) China's marine national defense tourism destination images have distinct regional characteristics. The cultural and military images of the northern coastal region were more distinct than the other two regions, the maritime and educational significance of the eastern coastal region was more prominent than the other two regions, and the historical and international characteristics of the southern coastal region were more significant than the other two regions. (2) The projected and perceived destination images of China's marine national defense tourism are focused on tourism. Each scenic spot emphasizes its own social and educational value, while tourists are more impressed by interactive and experiential events than by those ornamental events. 3) The dominant and consultative modes are the main dissemination modes of China's marine national defense tourism destination images, and the dominant mode is mainly embodied in national identity, which is presented through concrete cultural resources, educational activities, and so on. The negotiation model is more significant on tourism activities and tourism infrastructure, while no evident manifestations were observed in the oppositional model. Finally, this study provides recommendations for the construction and promotion of China's marine national defense tourism destination images, such as improving the infrastructure and services to enhance the tourism image, playing an active role in education to strengthen the national identity, broadening the channels of image dissemination, and paying attention to the management of guest-host co-construction.

• Intercropping intercepted more light than sole peanut but less than sole maize.• Maize light use efficiency (LUE) increased with plant density in the intercropping.• Intercropping did not affect LUE of maize but increased peanut LUE.Intercropping increases crop yields by optimizing light interception and/or use efficiency. Although intercropping combinations and metrics have been reported, the effects of plant density on light use are not well documented. Here, we examined the light interception and use efficiency in maize-peanut intercropping with different maize plant densities in two row configurations in semiarid dryland agriculture over a two-year period. The field experiment comprised four cropping systems, i.e. monocropped maize, monocropped peanut, maize-peanut intercropping with two rows of maize and four rows of peanut, intercropping with four rows of maize and four rows of peanut, and three maize plant densities (3.0, 4.5 and 6.0 plants m−1 row) in both monocropped and intercropping maize. The mean total light interception in intercropping across years and densities was 779 MJ·m−2, 5.5% higher than in monocropped peanut (737 MJ·m−2) and 7.6% lower than in monocropped maize (843 MJ·m−2). Increasing maize density increased light interception in monocropped maize but did not affect the total light interception in the intercrops. Across years the LUE of maize was 2.9 g·MJ−1 and was not affected by cropping system but increased with maize plant density. The LUE of peanut was enhanced in intercropping, especially in a wetter year. The yield advantage of maize-peanut intercropping resulted mainly from the LUE of peanut. These results will help to optimize agronomic management and system design and provide evidence for system level light use efficiency in intercropping.

The gut microbiome plays an important role in honeybee hormonal regulation and growth, but the underlying mechanisms are poorly understood. Here, we showed that the depletion of gut bacteria resulted in reduced expression of insulin-like peptide gene ( ilp ) in the head, accompanied by metabolic syndromes resembling those of Type 1 diabetes in humans: hyperglycemia, impaired lipid storage, and decreased metabolism. These symptoms were alleviated by gut bacterial inoculation. Gut metabolite profiling revealed that succinate, produced by Lactobacillus Firm-5, played deterministic roles in activating ilp gene expression and in regulating metabolism in honeybees. Notably, we demonstrated that succinate modulates host ilp gene expression through stimulating gut gluconeogenesis, a mechanism resembling that of humans. This study presents evidence for the role of gut metabolite in modulating host metabolism and contributes to the understanding of the interactions between gut microbiome and bee hosts., Competing Interests: Competing interests statement:The authors declare no competing interest.