The politics of Chinese trade and the Asian financial crises : questioning the wisdom of export-led growth

Between 1987 and 1996 Chinese exports increased by an average of 14% each year. During this decade, export growth became a crucial determinant of overall economic growth. However, as a consequence of the East Asian financial crises, Chinese export growth slowed, threatening the successful implementation of plans to restructure the domestic Chinese economy. This paper traces the reasons for the rapid growth and subsequent slowing of Chinese exports, and asks whether the strategy provides a solid basis for the long term development of the Chinese economy. In particular, the paper focuses on the role and significance of the processing trade in boosting Chinese exports. The high proportion of imported components in processed exports questions whether China is really benefiting as much from export growth as aggregate trade figures seem to suggest

Production and characterization of a recombinant single-chain antibody against Hantaan virus envelop glycoprotein

Hantaan virus (HTNV) is the type of Hantavirus causing hemorrhagic fever with renal syndrome, for which no specific therapeutics are available so far. Cell type-specific internalizing antibodies can be used to deliver therapeutics intracellularly to target cell and thus, have potential application in anti-HTNV infection. To achieve intracellular delivery of therapeutics, it is necessary to obtain antibodies that demonstrate sufficient cell type-specific binding, internalizing, and desired cellular trafficking. Here, we describe the prokaryotic expression, affinity purification, and functional testing of a single-chain Fv antibody fragment (scFv) against HTNV envelop glycoprotein (GP), an HTNV-specific antigen normally located on the membranes of HTNV-infected cells. This HTNV GP-targeting antibody, scFv3G1, was produced in the cytoplasm of Escherichia coli cells as a soluble protein and was purified by immobilized metal affinity chromatography. The purified scFv possessed a high specific antigen-binding activity to HTNV GP and HTNV-infected Vero E6 cells and could be internalized into HTNV-infected cells probably through the clathrin-dependent endocytosis pathways similar to that observed with transferrin. Our results showed that the E. coli-produced scFv had potential applications in targeted and intracellular delivery of therapeutics against HTNV infections

MICA/B expression is inhibited by unfolded protein response and associated with poor prognosis in human hepatocellular carcinoma

BackgroundMICA/B are major ligands for NK cell activating receptor NKG2D and previous studies showed that the serum level of soluble MICA (sMICA) is an independent prognostic factor for advanced human hepatocellular carcinoma. However, the correlation between cellular MICA/B expression pattern and human hepatocellular carcinoma progression has not been well explored. The unfolded protein response is one of the main causes of resistance to chemotherapy and radiotherapy in tumor cells. However, whether the UPR in HCC could regulate the expression levels of MICA/B and affect the sensitivity of HCC cells to NK cell cytolysis has not been established yet.MethodsMICA/B expression pattern was evaluated by immunohistochemistry and Kaplan-Meier survival analysis was done to explore the relationship between MICA/B expression level and patient survival. The protein and mRNA expression levels of MICA/B in SMMC7721 and HepG2 cells treated by tunicamycin were evaluated by flow cytometry, Western Blot and RT-PCR. The cytotoxicity analysis was performed with the CytoTox 96 Non-Radioactive LDH Cytotoxicity Assay.ResultsMICA/B was highly expressed in human hepatocellular carcinoma and the expression level was significantly and negatively associated with tumor-node metastasis (TNM) stages. Patients with low level of MICA/B expression showed a trend of shorter survival time. The unfolded protein response (UPR) downregulated the expression of MICA/B. This decreased protein expression occurred via post-transcriptional regulation and was associated with proteasomal degradation. Moreover, decreased expression level of MICA/B led to the attenuated sensitivity of human HCC to NK cell cytotoxicity.ConclusionThese new findings of the connection of MICA/B, UPR and NK cells may represent a new concrete theory of NK cell regulation in HCC, and suggest that targeting this novel NK cell-associated immune evasion pathway may be meaningful in treating patients with HCC.Electronic supplementary materialThe online version of this article (doi:10.1186/s13046-014-0076-7) contains supplementary material, which is available to authorized users

Microplastic accumulation in riverbed sediment via hyporheic exchange from headwaters to mainstems

In rivers, small and lightweight microplastics are transported downstream, but they are also found frequently in riverbed sediment, demonstrating long-term retention. To better understand microplastic dynamics in global rivers from headwaters to mainstems, we developed a model that includes hyporheic exchange processes, i.e., transport between surface water and riverbed sediment, where microplastic retention is facilitated. Our simulations indicate that the longest microplastic residence times occur in headwaters, the most abundant stream classification. In headwaters, residence times averaged 5 hours/km but increased to 7 years/km during low-flow conditions. Long-term accumulation for all stream classifications averaged ~5% of microplastic inputs per river kilometer. Our estimates isolated the impact of hyporheic exchange processes, which are known to influence dynamics of naturally occurring particles in streams, but rarely applied to microplastics. The identified mechanisms and time scales for small and lightweight microplastic accumulation in riverbed sediment reveal that these often-unaccounted components are likely a pollution legacy that is crucial to include in global assessments

Effect of Decreasing Biological Lability on Dissolved Organic Matter Dynamics in Streams

Respiration of dissolved organic matter (DOM) in streams contributes to the global CO2 efflux, yet this efflux has not been linked to specific DOM sources and their respective uptake rates. Further, removal of DOM inferred from longitudinal concentration gradients in river networks has been insufficient to account for observed CO2 outgassing. We hypothesize that understanding in‐stream dynamics of DOM, which is a heterogeneous mixture spanning a wide range of biological labilities, requires considering that DOM lability decreases during downstream transport. To test this hypothesis, we paired seasonal bioreactor measurements of DOM biological lability with whole‐stream tracer data from White Clay Creek, Pennsylvania, USA, and used a particle‐tracking model to predict in‐stream DOM dynamics. The model simulates continuous inputs of DOM and uses storage time in the stream bioactive regions plus kinetic parameters from bioreactors to assess differential uptake of DOM fractions (i.e., fractionation) in the stream. We compared predictions for in‐stream dynamics of bulk DOM concentration (quantified as dissolved organic carbon) and fluorescent DOM components. Our model‐data synthesis approach demonstrates that more labile fractions of DOM in stream water preferentially originate and are consumed within short travel distances, causing spiraling metrics to change with downstream distance. Our model can account for local sources of rapidly cycled labile DOM, providing a basis for improved interpretation of DOM dynamics in streams that can reconcile apparent discrepancies between respiratory outgassing of CO2 and longitudinal DOM concentration gradients within river networks.Plain Language SummaryIn streams, microorganisms metabolize naturally occurring organic molecules dissolved in streamwater and release carbon dioxide, which contributes to global carbon emissions. These organic molecules are part of a complex and diverse mixture including thousands of different chemical compounds that differ widely in susceptibility to biodegradation. We developed a mathematical model to describe changes in the pool of organic molecules flowing downstream, incorporating field and laboratory measurements of biological degradation of organic molecules and information about water flow into and out of zones that promote biological activity. We demonstrated that the molecules more susceptible to biodegradation are preferentially metabolized and become depleted over short travel distances downstream, while organic species less susceptible to biodegradation are transported farther downstream. Our model improves understanding of the transport and metabolism of organic molecules in streams, and explains factors that control the overall concentration of organic molecules in streams and rivers. The results help to reconcile discrepancies between estimates of carbon dioxide outgassing from streams and observations of organic carbon concentrations within streams.Key PointsDissolved organic matter (DOM) biological lability decreases with residence time in bioactive regions of the stream (defined as bioactive residence time)Decreasing biological lability, exchange into and residence times in bioactive regions influence in‐stream DOM dynamicsModel predictions show how the distribution of DOM fractions (i.e., fractionation) and spiraling metrics depend on in‐stream locationPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/166428/1/wrcr25082.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/166428/2/wrcr25082_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/166428/3/2020WR027918-sup-0001-Supporting_Information_SI-S01.pd

Transportation, economic growth and spillover effects: The conclusion based on the spatial econometric model

transportation, spillover effects, spatial autoregressive model, spatial moving average model, maximum likelihood estimation, L90, O18, R41,

Solute Transport and Transformation in an Intermittent, Headwater Mountain Stream with Diurnal Discharge Fluctuations

Time-variable discharge is known to control both transport and transformation of solutes in the river corridor. Still, few studies consider the interactions of transport and transformation together. Here, we consider how diurnal discharge fluctuations in an intermittent, headwater stream control reach-scale solute transport and transformation as measured with conservative and reactive tracers during a period of no precipitation. One common conceptual model is that extended contact times with hyporheic zones during low discharge conditions allows for increased transformation of reactive solutes. Instead, we found tracer timescales within the reach were related to discharge, described by a single discharge-variable StorAge Selection function. We found that Resazurin to Resorufin (Raz-to-Rru) transformation is static in time, and apparent differences in reactive tracer were due to interactions with different ages of storage, not with time-variable reactivity. Overall we found reactivity was highest in youngest storage locations, with minimal Raz-to-Rru conversion in waters older than about 20 h of storage in our study reach. Therefore, not all storage in the study reach has the same potential biogeochemical function and increasing residence time of solute storage does not necessarily increase reaction potential of that solute, contrary to prevailing expectations.ISSN:2073-444