Migration and Labor Mobility in China

China has witnessed the largest labor migration since the reform and opening up policies were implemented. According to the most recent statistics, the total number of rural to urban migrant workers reached 136 million. Migrants are defined as persons who have left out of township for more than 6 months. The migration flow has propelled the economic and societal transition in China through labor productivity enhancement and social restructuring. Accordingly, the Chinese government has improved the migration policies with increasing migration flow and the changes of labor market situations. This report is organized as follows. Section one briefly introduces when and how the migration started by reviewing the history, size and trend, impacts of migration in China and the vulnerability of migrants. Section two reviews the main migration policy changes in the past three decades. Section three illuminates the Lewisian turning point that marks economic development and transitioning in China. Section four discusses the relevance of China’s experiences to other developing economies in terms of economic development and migration policy changes.Migration in China, Labor mobility, Impact of crisis

Migration and Labor Mobility in China

China has witnessed the largest labor migration since the reform and opening up policies were implemented. According to the most recent statistics, the total number of rural to urban migrant workers reached 136 million. Migrants are defined as persons who have left out of township for more than 6 months. The migration flow has propelled the economic and societal transition in China through labor productivity enhancement and social restructuring. Accordingly, the Chinese government has improved the migration policies with increasing migration flow and the changes of labor market situations. This report is organized as follows. Section one briefly introduces when and how the migration started by reviewing the history, size and trend, impacts of migration in China and the vulnerability of migrants. Section two reviews the main migration policy changes in the past three decades. Section three illuminates the Lewisian turning point that marks economic development and transitioning in China. Section four discusses the relevance of China’s experiences to other developing economies in terms of economic development and migration policy changes

Simple and efficient expression of codon-optimized mouse leukemia inhibitory factor in Escherichia coli

Purpose: To obtain a higher yield of mouse leukemia inhibitory factor to maintain the proliferation potential of pluripotent stem cells at a low cost.Methods: A method was designed to produce recombinant mLIF protein (rmLIF) in Escherichia coli. Through analysis of rmLIF sequence, it was found that rare codons were interspersed. After mutation from rare codons to Escherichia coli (E. coli) preferred ones were selected, the mutated gene mLIFm was cloned into pET15b vector. The pET15b-mLIFm was then transformed into Rosetta-gami strain and induced with optimal conditions at 18 oC for 16 h. Mass spectrometry was carried out to identify the peptides.Results: After purification, the yield of the codon-optimized rmLIFm was 141 mg/L, compared with 110 mg/L for the original rmLIF. Mass spectral analysis showed the presence of four major peptides each with an intensity > 10 % at m/z 1031.57, 1539.82, 1412.01 and 2229.10 in mLIFm, respectively. Histagged rmLIFm fusion protein displayed the potential to maintain the morphology of undifferentiated mouse embryonic stem cells (mESCs), which were positive for mESCs markers (Oct-4, Nanog, Sox-2, stage-specific embryonic antigen-1).Conclusion: The findings provide a means to produce mLIF in a short, useful, cost-effective and environmentally-friendly manner, and thus lays a foundation for further studies of mLIF.Keywords: Leukemia inhibitory factor, Mutated gene, Protein expression, Purification, Stem cells, Peptides, Escherichia col

FVGWAS: Fast voxelwise genome wide association analysis of large-scale imaging genetic data

More and more large-scale imaging genetic studies are being widely conducted to collect a rich set of imaging, genetic, and clinical data to detect putative genes for complexly inherited neuropsychiatric and neurodegenerative disorders. Several major big-data challenges arise from testing genome-wide (NC > 12 million known variants) associations with signals at millions of locations (NV ~ 106) in the brain from thousands of subjects (n ~ 103). The aim of this paper is to develop a Fast Voxelwise Genome Wide Association analysiS (FVGWAS) framework to e ciently carry out whole-genome analyses of whole-brain data. FVGWAS consists of three components including a heteroscedastic linear model, a global sure independence screening (G-SIS) procedure, and a detection procedure based on wild bootstrap methods. Specifically, for standard linear association, the computational complexity is O(nNV NC) for voxelwise genome wide association analysis (VGWAS) method compared with O((NC + NV)n2) for FVGWAS. Simulation studies show that FVGWAS is an effcient method of searching sparse signals in an extremely large search space, while controlling for the family-wise error rate. Finally, we have successfully applied FVGWAS to a large-scale imaging genetic data analysis of ADNI data with 708 subjects, 193,275 voxels in RAVENS maps, and 501,584 SNPs, and the total processing time was 203,645 seconds for a single CPU. Our FVG-WAS may be a valuable statistical toolbox for large-scale imaging genetic analysis as the field is rapidly advancing with ultra-high-resolution imaging and whole-genome sequencing