Livelihood Capital and Livelihood Diversification for Different Farmers in Yuanjiang Dry-Hot River Valley

Under the analytical framework of sustainable livelihoods,we establish the evaluation indicator system for farmers' livelihood capital,to evaluate the current livelihood capital and livelihood diversification for different farmers in the Dai nationality region of Xinping County in the Yuanjiang dry-hot river valley area,and discuss the relationship between livelihood capital and livelihood diversification. Studies have shown that the mode dominated by agriculture,supplemented by non-agricultural activities,combined with breeding,is the commonly used livelihood strategy for farmers in this region. As farmers change from pure agriculture to non-agriculture,their total livelihood capital and nonagricultural livelihood diversification index will increase,while agricultural livelihood diversification index will decrease. In the meantime,their livelihood activities gradually shift from agricultural to non-agricultural ones,which is mainly reflected in the combination of both agricultural and non-agricultural activities. Regression analysis on livelihood capital and livelihood diversification shows that natural and physical capital is the basis of realizing agricultural livelihood diversification. Farmers with rich natural and physical capital will prefer agricultural livelihood strategies. While financial and human capital is the driving force for farmers' transition from pure agriculture to non-agriculture.

Temperature acclimation in hot-spring snakes and the convergence of cold response

Animals have evolved sophisticated temperature-sensing systems and mechanisms to detect and respond to ambient temperature changes.As a relict species endemic to the Qinghai-Tibet Plateau,hot-spring snake(Thermophis baileyi)survived the dramatic changes in climate that occurred during plateau uplift and ice ages,providing an excellent opportunity to explore the evolution of temperature sensation in ectotherms.Based on distributional information and behavioral experiments,we found that T.baileyi prefer hotspring habitats and respond more quickly to warmth than other two snakes,suggesting that T.baileyi may evolve an efficient thermal-sensing system.Using high-quality chromosome-level assembly and comparative genomic analysis,we identified cold acclimation genes experiencing convergent acceleration in high-altitude lineages.We also discovered significant evolutionary changes in thermosensation-and thermoregulation-related genes,including the transient receptor potential(TRP)channels.Among these genes,TRPA1 exhibited three species-specific amino acid replacements,which differed from those found in infrared imaging snakes,implying different temperature-sensing molecular strategies.