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The macro environment of the economy during the reform and opening-up in China for over 40 years evolved with the market-oriented reform and the economic development, which is quite different from the developed areas such as the U.S. and Western Europe where the economies have been in a market-economic setting that is relatively fixed. During the whole course of the reform and opening-up, the Chinese economy became increasingly integrated with external economies and other countries drew more and more from China’s experiences in the macroeconomic management. By learning from developed economies on the macroeconomic management to draw on the lessons of the developed and even developing and emerging economies while continuously adapting to the unique system and development background of its own, China has developed a set of macroeconomic management theories and policy framework with Chinese characteristics.

In 2007, the World Bank published the report, “An East Asian Renaissance: Ideas for Economic Growth,” and raised the issue of “a middle income trap” for the first time. In “China 2030: Building a Modern, Harmonious, and Creative Society,” released in 2012 by the World Bank and the Development Research Center of the State Council of the People’s Republic of China, it was estimated that out of 101 middle-income economies in 1960, only 13 became high-income by 2008, namely, Greece, Ireland, Portugal, Spain, Japan, the Republic of Korea, Singapore, Hong Kong SAR (China), Israel, Puerto Rico, Equatorial Guinea, Mauritius, and Taiwan of China.

The construction of the bacterial cell envelope is a fundamental topic, as it confers its integrity to bacteria and is consequently the target of numerous antibiotics. MreB is an essential protein suspected to regulate the cell wall synthetic machineries. Despite two decades of study, its localization remains the subject of controversies, its description ranging from helical filaments spanning the entire cell to small discrete entities. The true structure of these filaments is important because it impacts the model describing how the machineries building the cell wall are associated, how they are coordinated at the scale of the entire cell, and how MreB mediates this regulation. Our results shed light on this debate, revealing the size of native filaments in B. subtilis during growth. They argue against models where MreB filament size directly affects the speed of synthesis of the cell wall and where MreB would coordinate distant machineries along the side wall., The actin-like MreB protein is a key player of the machinery controlling the elongation and maintenance of the cell shape of most rod-shaped bacteria. This protein is known to be highly dynamic, moving along the short axis of cells, presumably reflecting the movement of cell wall synthetic machineries during the enzymatic assembly of the peptidoglycan mesh. The ability of MreB proteins to form polymers is not debated, but their structure, length, and conditions of establishment have remained unclear and the subject of conflicting reports. Here we analyze various strains of Bacillus subtilis, the model for Gram-positive bacteria, and we show that MreB forms subdiffraction-limited, less than 200 nm-long nanofilaments on average during active growth, while micron-long filaments are a consequence of artificial overaccumulation of the protein. Our results also show the absence of impact of the size of the filaments on their speed, orientation, and other dynamic properties conferring a large tolerance to B. subtilis toward the levels and consequently the lengths of MreB polymers. Our data indicate that the density of mobile filaments remains constant in various strains regardless of their MreB levels, suggesting that another factor determines this constant.

Many middle income economies have been unable to advance to become high income economies over a period of 50 years or longer, not due to the existence of middle income traps, but because of the overly broad income range in the definition of middle income economies. The middle income trap is, in essence, a growth trap, and refers to the situation in which a middle income economy experiences growth stagnation or a growth rate that is lower than that of high income economies. Nonetheless, it is hard to fully comprehend the formation of the trap solely based on growth theories. Historical data indicate that the middle income economies do not lack growth potential, and the real problem is that although their long-term average growth rates are higher than those of the high income economies, their average growth rates over a business cycle or an even longer period of time often fall below those of the high income economies. The cause of this phenomenon is neither short-term macroeconomic fluctuations nor long-term growth potential, but the frequent occurrence of financial crises in middle income economies. As a middle income economy, China is also facing the risk of a financial crisis, and the key to avoiding the middle income trap is to guard against future financial crises, preventing unsound financial liberalization and mismanagement of the corporate debt ratio.

MreB proteins play a major role during morphogenesis of rod-shaped bacteria by organizing biosynthesis of the peptidoglycan cell wall. However, the mechanisms underlying this process are not well understood. In Bacillus subtilis, membrane-associated MreB polymers have been shown to be associated to elongation-specific complexes containing transmembrane morphogenetic factors and extracellular cell wall assembly proteins. We have now found that an early intracellular step of cell wall synthesis is also associated to MreB. We show that the previously uncharacterized protein YkuR (renamed DapI) is required for synthesis of meso-diaminopimelate (m-DAP), an essential constituent of the peptidoglycan precursor, and that it physically interacts with MreB. Highly inclined laminated optical sheet microscopy revealed that YkuR forms uniformly distributed foci that exhibit fast motion in the cytoplasm, and are not detected in cells lacking MreB. We propose a model in which soluble MreB organizes intracellular steps of peptidoglycan synthesis in the cytoplasm to feed the membrane-associated cell wall synthesizing machineries.

The appearance of new product varieties and improvements in the quality of goods have both played key roles in the rapid growth of China's exports. However, these two important elements have not been formally integrated into the demand equations for China's exports. As we demonstrate in this paper, income elasticity will be underestimated if new varieties of goods and quality improvements are omitted in price index and quantity index calculations, which are necessary for estimating the export demand function. Moreover, the faster new product varieties enter export markets, the greater the underestimation will be. In this paper, we develop an export demand equation that takes into account new product varieties and improvements in quality, and then calculate the demand function for China's exports using the data from 1992 to 2006. According to our estimation, the short-term income elasticity of demand for China's exports is approximately 2.34, and the short-term price elasticity is approximately –0.65. Our estimation predicts an increase in China's export value in the case of an RMB appreciation or export rebate rates reduction in the short term, due to the low price elasticity of China's exports, whose absolute value is less than 1. Our findings are novel and could have significant policy implications.

The bacterial cell wall is conserved in prokaryotes, stabilizing cells against osmotic stress. Beta-lactams inhibit cell-wall synthesis and induce lysis through a bulge-mediated mechanism; however, little is known about the formation dynamics and stability of these bulges. To capture processes of different timescales, we developed an imaging platform combining automated image analysis with live-cell microscopy at high time resolution. Beta-lactam killing of Escherichia coli cells proceeded through four stages: elongation, bulge formation, bulge stagnation, and lysis. Both the cell wall and outer membrane (OM) affect the observed dynamics; damaging the cell wall with different beta-lactams and compromising OM integrity cause different modes and rates of lysis. Our results show that the bulge-formation dynamics are determined by how the cell wall is perturbed. The OM plays an independent role in stabilizing the bulge once it is formed. The stabilized bulge delays lysis and allows recovery upon drug removal.

Fluorescent proteins and developments in superresolution (nanoscopy) and single-molecule techniques bring high sensitivity, speed, and one order of magnitude gain in spatial resolution to live-cell imaging. These technologies have only recently been applied to prokaryotic cell biology, revealing the exquisite subcellular organization of bacterial cells. Here, we review the parallel evolution of fluorescence microscopy methods and their application to bacteria, mainly drawing examples from visualizing actin-like MreB proteins in the model bacterium Bacillus subtilis. We describe the basic principles of nanoscopy and conventional techniques and their advantages and limitations to help microbiologists choose the most suitable technique for their biological question. Looking ahead, multidimensional live-cell nanoscopy combined with computational image analysis tools, systems biology approaches, and mathematical modeling will provide movie-like, mechanistic, and quantitative description of molecular events in bacterial cells.

MreB proteins play a major role during morphogenesis of rod-shaped bacteria by organizing biosynthesis of the peptidoglycan cell wall. However, the mechanisms underlying this process are not well understood. In Bacillus subtilis, membrane-associated MreB polymers have been shown to be associated to elongation-specific complexes containing transmembrane morphogenetic factors and extracellular cell wall assembly proteins. We have now found that an early intracellular step of cell wall synthesis is also associated to MreB. We show that the previously uncharacterized protein YkuR (renamed DapI) is required for synthesis of meso-diaminopimelate (m-DAP), an essential constituent of the peptidoglycan precursor, and that it physically interacts with MreB. Highly inclined laminated optical sheet microscopy revealed that YkuR forms uniformly distributed foci that exhibit fast motion in the cytoplasm, and are not detected in cells lacking MreB. We propose a model in which soluble MreB organizes intracellular steps of peptidoglycan synthesis in the cytoplasm to feed the membrane-associated cell wall synthesizing machineries.

Cell size varies greatly among different types of cells, but the range in size that a specific cell type can reach is limited. A long-standing question in biology is how cells control their size. Escherichia coli adjusts size and growth rate according to the availability of nutrients so that it grows larger and faster in nutrient-rich media than in nutrient-poor media. Here, we describe how, using classical genetics, we have isolated a remarkably small E. coli mutant that has undergone a 70% reduction in cell volume with respect to wild type. This mutant lacks FabH, an enzyme involved in fatty acid biosynthesis that previously was thought to be essential for the viability of E. coli . We demonstrate that although FabH is not essential in wild-type E. coli , it is essential in cells that are defective in the production of the small-molecule and global regulator ppGpp. Furthermore, we have found that the loss of FabH causes a reduction in the rate of envelope growth and renders cells unable to regulate cell size properly in response to nutrient excess. Therefore we propose a model in which fatty acid biosynthesis plays a central role in regulating the size of E. coli cells in response to nutrient availability.

β-lactam antibiotics inhibit penicillin binding proteins (PBPs) involved in peptidoglycan synthesis. Although inhibition of peptidoglycan biosynthesis is generally thought to induce cell lysis, the pattern and mechanism of cell lysis can vary substantially. β-lactams that inhibit FtsI, the only division specific PBP, block cell division and result in growth as filaments. These filaments ultimately lyse through a poorly understood mechanism. Here we find that one such β-lactam, cephalexin, can, under certain conditions, lead instead to rapid lysis at nascent division sites through a process that requires the complete and ordered assembly of the divisome, the essential machinery involved in cell division. We propose that this assembly process (in which the localization of cell wall hydrolases depends on properly targeted FtsN, which in turn depends on the presence of FtsI) ensures that the biosynthetic machinery to form new septa is in place before the machinery to degrade septated daughter cells is enabled. β-lactams that target FtsI subvert this mechanism by inhibiting FtsI without perturbing the normal assembly of the cell division machinery and the consequent activation of cell wall hydrolases. One seemingly paradoxical implication of our results is that β-lactam therapy may be improved by promoting active cell division.