Genomic evidence sheds new light on phylogeny of Rhabdophis nuchalis (sensu lato) complex (Serpentes: Natricidae).

Stable taxonomy and robust phylogeny are essential for the evolution and conservation of organisms. The Rhabdophis nuchalis (sensu lato) complex presently contains three species (R. nuchalis, R. chiwen, R. pentasupralabialis). Although several studies have explored the diversity and phylogeography of this group, certain issues related to systematics and taxonomy remain unresolved. Here, based on genome-wide data, including single nucleotide polymorphisms (SNPs) generated from ddRAD-seq and mitochondrial DNA (mtDNA), we re-evaluated the phylogenetic relationships and cryptic diversity of this species group. Our results are generally consistent with previous studies but provide some new insights. Phylogenetic relationship reconstruction based on SNPs and mtDNA revealed that three species in the R. nuchalis (sensu lato) complex did not form a monophyly but each species is well supported as monophyletic lineage in SNP-based analyses. Population structure analyses showed genetic admixture between several species pairs. Additionally, the population in eastern Yunnan, China, was identified as a potential cryptic species and thus described as a new species based on morphological data. From our results and previous studies, we redefined the distribution boundary for each species in the R. nuchalis (sensu lato) species complex.

Comparative pharmacokinetics of intravenous and intramuscular cefquinome sulfate administration in ducklings and goslings.

OBJECTIVE: To compare the pharmacokinetics of cefquinome sulfate in ducklings and goslings after IV or IM administration of a single dose. ANIMALS: 216 healthy Muscovy ducklings (Cairina moschata) and 216 healthy Sichuan white goslings (Anser cygnoides). PROCEDURES: Ducklings and goslings were each randomly assigned to 3 groups (n = 72/group) that received a single dose (2 mg/kg) of injectable cefquinome sulfate administered IV or IM or of injectable cefquinome sulfate suspension administered IM. Blood samples were collected at various points after drug administration (n = 6 birds/time point). Plasma cefquinome concentrations were measured by high-performance liquid chromatography with UV detection, and pharmacokinetic parameters were calculated with a 2-compartment model method. RESULTS: After IV injection, mean distribution half-life of cefquinome was longer in goslings (0.446 hours) than in ducklings (0.019 hours), whereas volume of distribution at steady state was greater (0.432 vs 0.042 L/kg) and elimination half-life was slower (1.737 vs 0.972 hours). After IM administration of injectable cefquinome sulfate, bioavailability of the drug was higher in goslings (113.9%) than in ducklings (67.5%). After IM administration of injectable cefquinome sulfate suspension, bioavailability was also higher in goslings (123.1%) than in ducklings (96.8%), whereas elimination half-life was slower (6.917 vs 1.895 hours, respectively). CONCLUSIONS AND CLINICAL RELEVANCE: In goslings, IV administration of cefquinome resulted in slower distribution and metabolism of the drug than in ducklings and IM administration resulted in higher bioavailability. The delayed-release effect of the injectable cefquinome sulfate suspension when administered IM was observed only in goslings.

Environmental conscience, external incentives and social norms in rice farmers' adoption of pro-environmental agricultural practices in rural Hubei province, China.

This paper attempts to address a recurring theme in agricultural resources and environmental economics - the low adoption rates of pro-environmental agricultural practices in many developing countries. By improving the Norm-activation model, this paper incorporates external incentives and social norms into the framework and employs multivariate probit and ordered probit models to explore how environmental conscience, external incentives and social norms influence rice farmers' adoption behaviours and intensive use of pro-environmental agricultural practices. The case study, involving 954 household-level data of rice farmers from rural Hubei province, China, reveals that the adoption rates of certain practices are very low, and that only 6.5% rice farmers adopt three or more pro-environmental agricultural practices. Results show that straw returning and soil testing and fertilizer recommendation are complementaries, and that environmental conscience, external incentives and social norms all positively affect the adoption behaviours, while the adoption intensity is significantly influenced by awareness of consequences, perceived efficacy, external incentives and descriptive norm. These findings underscore that policy interventions to improve rice farmers' environmental conscience, to provide well-designed external incentives and to activate social norms are needed to enhance the adoption of pro-environmental agricultural practices in developing countries.

Who cares what parents think or do? Observational learning and experience-based learning through communication in rice farmers' willingness to adopt sustainable agricultural technologies in Hubei Province, China.

Sustainable agricultural technologies are of great significance in fully utilizing agricultural resources and promoting agricultural production. However, the adoption rates of these technologies are often characterized as low in rural areas in China. To figure out the potential salient determinants of rice farmers' willingness to adopt sustainable agricultural technologies, this paper, by employing the multivariate probit model and ordered probit model, particularly and firstly explores the roles of observational learning and experience-based learning through communication from parents within the household on rice farmers' willingness to adopt these technologies. Results show that there are strong complementarities and substitutabilities between sustainable agricultural technologies that rice farmers are willing to adopt, and that observational learning and experience-based learning through communication within the household do have pronounced effects on rice farmers' willingness to adopt some sustainable agricultural technologies and on their intensive use intentions. Therefore, while formulating policies to improve the adoption rates and adoption intensity of these technologies, relevant government agencies should take the complementarities and substitutabilities between sustainable agricultural technologies as well as observational learning and experience-based learning through communication from parents into consideration.

Knowledge domain and emerging trends of agricultural waste management in the field of social science: A scientometric review.

Many studies have been conducted on agricultural waste management, especially review articles; however, there are few literature analyses from the scientometric and bibliometric perspective. This study is one of the first to offer insights into the research topics and trend evaluation in terms of agricultural waste management over time. Our main findings are as follows: For nearly half a century, the United States has maintained the leading position in research on agricultural waste management. Many core research institutions or scholars are also from the United States. There are four major areas in this field: the research on the low-carbon and energy utilization of agricultural waste, the influence of agricultural waste emissions, the material and energy flow of agricultural waste and the prevention and control of agricultural waste pollution. As time progresses and with the development of environment, economy and society, the popular research topics in different stages vary, but on the whole, the research on agricultural waste management has emerged in the early stage. With the change of global natural resource conditions and political and economic background, there are more space for the future. We believe that research on greenhouse gas emission reduction from agricultural waste management based on specific social policies is extremely urgent, and will be of great significance in reducing agricultural greenhouse gas emission.

A scientometric review of emerging trends and new developments in agricultural ecological compensation.

Agricultural ecological compensation has drawn an increasingly broad range of interest since early 1990s. In recent years, the volume of the literature grows rapidly. As a result, a systematic review of the diverse research field and its current trends becomes essential. This paper surveys the literature of agricultural ecological compensation between 1990 and 2016. Specifically, by employing CiteSpace information visualization software, we firstly identified the research hotspots and evolution path and then illustrated the frontier and developing trend of the domain in core and broader perspectives. It is found that the focus of the academic community has always been researches on the theoretical policy and application of the payment for agro-ecosystem services, agricultural ecological compensation based on contingent valuation method, and ecological compensation of farmland landscape and organic food production as well as willingness to accept/pay for land use and ecological protection. Meanwhile, we also found that, in recent years, qualitative research has received more and more attention in the field of agricultural ecological compensation, since global warming, agricultural carbon emissions, and other emerging environmental issues have aroused widespread concern of the people around the world. Moreover, we believed that more and more scholars will employ case study methodology to analyze agricultural ecological compensation in specific systems, regions, or circumstances in the future.