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Can the expansion of a prosperous middle class help China to rebalance to consumption-led growth? We address this question through analysis of macro- and micro-level data. Using macro statistics, we examine trends in national aggregate consumption and GDP growth from 2000 through 2019. We observe growth in aggregate consumption but do not find convincing evidence of consumption-led growth. Using micro-level household survey data from 2002, 2007, 2013 and 2018, we estimate the size of China's prosperous middle class and its contribution to aggregate consumption growth. We find that the prosperous middle class expanded rapidly but contributed less to aggregate consumption growth than expected. We discuss features of this class that diminished its contribution to consumption-led growth, including its low propensity to consume out of income and its limited expansion beyond urban subgroups. We conclude that the expansion of the prosperous middle class is necessary but not sufficient to bring about rebalancing. [ABSTRACT FROM AUTHOR]

The adenosine 5ʹ-triphosphate (ATP)-binding cassette (ABC) transporter, IrtAB, plays a vital role in the replication and viability of Mycobacterium tuberculosis (Mtb), where its function is to import iron-loaded siderophores. Unusually, it adopts the canonical type IV exporter fold. Herein, we report the structure of unliganded Mtb IrtAB and its structure in complex with ATP, ADP, or ATP analogue (AMP-PNP) at resolutions ranging from 2.8 to 3.5 Å. The structure of IrtAB bound ATP-Mg2+ shows a "head-to-tail" dimer of nucleotide-binding domains (NBDs), a closed amphipathic cavity within the transmembrane domains (TMDs), and a metal ion liganded to three histidine residues of IrtA in the cavity. Cryo-electron microscopy (Cryo-EM) structures and ATP hydrolysis assays show that the NBD of IrtA has a higher affinity for nucleotides and increased ATPase activity compared with IrtB. Moreover, the metal ion located in the TM region of IrtA is critical for the stabilization of the conformation of IrtAB during the transport cycle. This study provides a structural basis to explain the ATP-driven conformational changes that occur in IrtAB. [ABSTRACT FROM AUTHOR]

Using the data of Chinese Household Income Project (CHIP) for years 2002--2018, this paper analyzes the trend of inequality of opportunity (IOp) in earnings for people of working age (26--50 years old) in China. It is found that, in recent 20 years, the IOp has shown a downward trend, which is mainly due to the change of circumstances that lie beyond the control of individuals, rather than the structural change of sub-population. Among the circumstances, the influence of region and hukou at birth gradually decreased; that of individual characteristics ( gender and age) gradually intensified; and that of parental characteristics ( education and occupation) has been high and even rising. This suggests the important role of intergenerational transmission of education in IOp. Rural registered residents have a higher chance of facing unequal opportunities than urban registered residents. We also find that the IOp increased with age. This paper emphasizes that it is necessary to give appropriate support to the disadvantaged groups, and provide them with enough platforms and smooth channels to change their destiny and finally achieve common prosperity. [ABSTRACT FROM AUTHOR]

Electrostatic coalescence of the water droplets in water-in-oil (W/O) emulsion plays a significant role in demulsification process. As the droplets collide and aggregate with each other, the dispersed droplets may coalesce and separate from continuous phase. Several mechanisms simultaneously contribute to the complexity associated with droplets coalescence. Thus, an appropriate simulation approach is needed to predict electrostatic coalescence performance in W/O emulsion. In this work, the population balance model (PBM) was used to predict coalescence performance of W/O emulsion under electric field. The proposed approach is novel as it integrates various mathematical models to study dispersed droplets collision frequency considering Boltzmann motion, differential settlement, and electric field. Moreover, a new collision efficiency model, which is best proper for the droplet size between 1 μm and 100 μm, is also proposed to make the prediction model more accurate. The simulation results were verified by comparing with existing experimental datasets. After that, a sensitivity analysis was carried out to study parameters that affect electrostatic coalescence performance, such as electric field strength, dispersion permittivity, continuous viscosity, and collision efficiency coefficient. The results show that the higher voltage and droplet permittivity both lead to the greater electrostatic coalescence performance, but the increments are gradually smaller under the condition of neglecting the droplet fragmentation. With the increasing of continuous viscosity, the droplet size median significantly decreases at first and then flattens. Meanwhile, the performance of electrostatic coalescence is greater at bigger collision efficiency coefficient. But the variation of volume size median with collision efficiency coefficient is modest. The simulation approach proposed in this paper provides an in-depth understanding of the dispersed droplets collision in electric field, which provides useful insights for prediction of electrostatic coalescence performance of W/O emulsion in petroleum industries. [ABSTRACT FROM AUTHOR]

Drug-resistant Tuberculosis (TB) is a global public health problem. Resistance to rifampicin, the most effective drug for TB treatment, is a major growing concern. The etiological agent, Mycobacterium tuberculosis ( Mtb ), has a cluster of ATP-binding cassette (ABC) transporters which are responsible for drug resistance through active export. Here, we describe studies characterizing Mtb Rv1217c-1218c as an ABC transporter that can mediate mycobacterial resistance to rifampicin and have determined the cryo-electron microscopy structures of Rv1217c-1218c. The structures show Rv1217c-1218c has a type V exporter fold. In the absence of ATP, Rv1217c-1218c forms a periplasmic gate by two juxtaposed-membrane helices from each transmembrane domain (TMD), while the nucleotide-binding domains (NBDs) form a partially closed dimer which is held together by four salt-bridges. Adenylyl-imidodiphosphate (AMPPNP) binding induces a structural change where the NBDs become further closed to each other, which downstream translates to a closed conformation for the TMDs. AMPPNP binding results in the collapse of the outer leaflet cavity and the opening of the periplasmic gate, which was proposed to play a role in substrate export. The rifampicin-bound structure shows a hydrophobic and periplasm-facing cavity is involved in rifampicin binding. Phospholipid molecules are observed in all determined structures and form an integral part of the Rv1217c-1218c transporter system. Our results provide a structural basis for a mycobacterial ABC exporter that mediates rifampicin resistance, which can lead to different insights into combating rifampicin resistance., Competing Interests: Competing interests statement:The authors declare no competing interest.

The type I adenosine 5'-triphosphate (ATP)-binding cassette (ABC) transporter DppABCD is believed to be responsible for the import of exogenous heme as an iron source into the cytoplasm of the human pathogen Mycobacterium tuberculosis ( Mtb ). Additionally, this system is also known to be involved in the acquisition of tri- or tetra-peptides. Here, we report the cryo-electron microscopy structures of the dual-function Mtb DppABCD transporter in three forms, namely, the apo , substrate-bound, and ATP-bound states. The apo structure reveals an unexpected and previously uncharacterized assembly mode for ABC importers, where the lipoprotein DppA, a cluster C substrate-binding protein (SBP), stands upright on the translocator DppBCD primarily through its hinge region and N-lobe. These structural data, along with biochemical studies, reveal the assembly of DppABCD complex and the detailed mechanism of DppABCD-mediated transport. Together, these findings provide a molecular roadmap for understanding the transport mechanism of a cluster C SBP and its translocator.

Arabinogalactan (AG) is an essential cell wall component in mycobacterial species, including the deadly human pathogen Mycobacterium tuberculosis . It plays a pivotal role in forming the rigid mycolyl-AG-peptidoglycan core for in vitro growth. AftA is a membrane-bound arabinosyltransferase and a key enzyme involved in AG biosynthesis which bridges the assembly of the arabinan chain to the galactan chain. It is known that AftA catalyzes the transfer of the first arabinofuranosyl residue from the donor decaprenyl-monophosphoryl-arabinose to the mature galactan chain (i.e., priming); however, the priming mechanism remains elusive. Herein, we report the cryo-EM structure of Mtb AftA. The detergent-embedded AftA assembles as a dimer with an interface maintained by both the transmembrane domain (TMD) and the soluble C-terminal domain (CTD) in the periplasm. The structure shows a conserved glycosyltransferase-C fold and two cavities converging at the active site. A metal ion participates in the interaction of TMD and CTD of each AftA molecule. Structural analyses combined with functional mutagenesis suggests a priming mechanism catalyzed by AftA in Mtb AG biosynthesis. Our data further provide a unique perspective into anti-TB drug discovery.