中国四个城市吸引海外回流人才比较研究：一个政策的视角 (Returned highly skilled migrants in four Chinese cities: a policy perspective)

Most studies of returned highly skilled migrants in China were guided by a national approach, emphasizing how the size and direction of the return migration were shaped by national policies and practices. What have been overlooked are the flows of returned skills at the municipal level where talent attraction and employment really take place. To fill this gap, the author conducted a comparative study of the returned highly-skilled migration in Beijing, Shanghai, Guangzhou and Shenzhen, the four most important cities in China. Based on in-depth interviews with returned skills from different countries and with various occupational backgrounds, complemented by the analysis of talent policies that have been issued by each city since the early 1990s and relevant statistical data, this study finds that, first, municipal cities tend to make ‘localized policies’ in order to suit local situation and to increase flexibility and efficiency in their effort of enticing of talents, demonstrating a wide range of variations not yet discussed in previous literature. It is thus crucial to pay timely attention to municipalities in order to obtain a more accurate and balanced picture of returned skilled migration in China. Second, the flow of returned skills shall be perceived in a broader analytical framework, in which the attractiveness to skills comes mostly from the long-term career potentials made possible by the industrial structure of individual city and mediated by social, cultural and geographical factors. It is only within this larger framework and through the interaction with other factors that government policies play their modulator roles.

From traditional resource to global commodities: a comparison of Rhodiola species using NMR spectroscopy - metabolomics and HPTLC

The fast developing international trade of products based on traditional knowledge and their value chains has become an important aspect of the ethnopharmacological debate. The structure and diversity of value chains and their impact on the phytochemical composition of herbal medicinal products has been overlooked in the debate about quality problems in transnational trade. Different government policies and regulations governing trade in herbal medicinal products impact on such value chains. Medicinal Rhodiola species, including Rhodiola rosea L. and Rhodiola crenulata (Hook.f. & Thomson) H.Ohba, have been used widely in Europe and Asia as traditional herbal medicines with numerous claims for their therapeutic effects. Faced with resource depletion and environment destruction, R. rosea and R. crenulata are becoming endangered, making them more economically valuable to collectors and middlemen, and also increasing the risk of adulteration and low quality. We compare the phytochemical differences among Rhodiola raw materials available on the market to provide a practical method for Rhodiola authentication and the detection of potential adulterant compounds. Samples were collected from Europe and Asia and nuclear magnetic resonance spectroscopy coupled with multivariate analysis software and high performance thin layer chromatography techniques were used to analyse the samples. A method was developed to quantify the amount of adulterant species contained within mixtures. We compared the phytochemical composition of collected Rhodiola samples to authenticated samples. Rosavin and rosarin were mainly present in R. rosea whereas crenulatin was only present in R. crenulata. 30% of the Rhodiola samples purchased from the Chinese market were adulterated by other Rhodiola spp. Moreover, 7 % of the raw-material samples were not labelled satifactorily. The utilisation of both 1H-NMR and HPTLC methods provided an integrated analysis of the phytochemical differences and novel identification method for R. rosea and R. crenulata. Using 1H-NMR spectroscopy it was possible to quantify the presence of R. crenulata in admixtures with R. rosea. This quantitative technique could be used in the future to assess a variety of herbal drugs and products. This project also highlights the need to further study the links between producers and consumers in national and trans-national trade.