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Indoor environments with displacement ventilation or under-floor air distribution commonly exhibit thermal stratification, which can impact the dispersion of droplets in exhaled air by moving human sources. This paper presented an experimental study using a water tank to simulate the coupling characteristics of exhaled airflow and human motion-induced oncoming airflow, especially in a stratified environment. The effects of exhalation velocity and movement speed were studied. Results show that the buoyant jet flow couples with the oncoming flow, firstly spreading forwards and upwards, forming the impinging region, where the penetration distance is found to vary linearly with the ratio of movement velocity and exhalation velocity. Then the coupled flow spreads backwards, forming the wake region behind the source, where the flow rises upwards, albeit at a slower rate than in motionless conditions. In the wake region, there is an obvious stagnant layer, which is exacerbated by the thermal stratification of the ambient fluid and much lower than the lock-up height of motionless buoyant jet flow. It is expected to provide scientific basis for formulating prevention and control measures in public spaces. • Interaction of buoyant jet flow and motion-induced airflow was experimentally studied. • Impinging region and wake region were observed in the dispersion of coupled flow. • Penetration distance in impinging region varies linearly with the velocity ratio. • The coupled flow rises more slowly and disperses at a low stagnant layer. • The stagnation in wake region is exacerbated by thermal stratification. [ABSTRACT FROM AUTHOR]

The impacts of the Arctic stratospheric polar vortex (SPV) changes on wintertime frontogenesis in the northern middle latitudes are analyzed. Both composite analysis and model simulations reveal that the intensity and frequency of frontogenesis over West Russia, the Mongolian Plateau, the Mediterranean and the southern North Atlantic during weak SPV years are significantly stronger and larger than those during strong SPV years, while the frontogenesis over the northern parts of the North Atlantic and North Pacific Oceans are weaker and less occur during weak SPV years. These features are more noticeable in middle January and February. The contributions of resultant deformation changes to frontogenesis intensity changes over most regions of the middle latitudes are larger than those of horizontal divergence changes, and the contribution of stretching deformation is slightly larger than that of shearing deformation. The changes in frontogenesis intensity are attributed to changes in the tropospheric circulation and temperature gradient associated with the SPV changes. Potential vorticity (PV) anomalies in the upper troposphere and lower stratosphere (UTLS) caused by the weakened and shifted SPV towards Eurasia lead to tropospheric cyclonic flows, favoring more cold-air mass transported towards mid-latitude Eurasia. Meanwhile, more high-PV air towards Eurasia results in steeper tropospheric isentropes during weak SPV years. Consequently, both temperature gradient and frontogenesis over Russia are enhanced. More southward transport of cold-air mass due to the equatorward shift of the polar jet stream induced by the weak SPV enhances the frontogenesis over the southern North Atlantic. Furthermore, the angle between dilatation axis and the isentropes over West Russia, the Mongolian Plateau and the southern North Atlantic is more likely to occur between 0° and 45°, which promotes stronger frontogenesis over these regions during weak SPV years. By contrast, opposite processes occur over the northern North Atlantic, causing weaker frontogenesis there. • Weak SPV enhances frontogenesis in some regions over the northern middle latitudes. • Resultant deformation dominates the SPV-induced frontogenesis changes. • Weakened and shifted SPV induce stronger cold air and frontogenesis. • Favorable angle between dilatation axis and isentropes promotes frontogenesis. [ABSTRACT FROM AUTHOR]

Endoplasmic reticulum-associated degradation (ERAD) is an important function for cellular homeostasis. The mechanism of how picornavirus infection interferes with ERAD remains unclear. In this study, we demonstrated that enterovirus 71 (EV71) infection significantly inhibits cellular ERAD by targeting multiple key ERAD molecules with its proteases 2Apro and 3Cpro using different mechanisms. Ubc6e was identified as the key E2 ubiquitin-conjugating enzyme in EV71 disturbed ERAD. EV71 3Cpro cleaves Ubc6e at Q219G, Q260S, and Q273G. EV71 2Apro mainly inhibits the de novo synthesis of key ERAD molecules Herp and VIMP at the protein translational level. Herp differentially participates in the degradation of different glycosylated ERAD substrates α-1 antitrypsin Null Hong Kong (NHK) and the C-terminus of sonic hedgehog (SHH-C) via unknown mechanisms. p97 was identified as a host factor in EV71 replication; it redistributed and co-exists with the viral protein and other known replication-related molecules in EV71-induced replication organelles. Electron microscopy and multiple-color confocal assays also showed that EV71-induced membranous vesicles were closely associated with the endoplasmic reticulum (ER), and the ER membrane molecule RTN3 was redistributed to the viral replication complex during EV71 infection. Therefore, we propose that EV71 rearranges ER membranes and hijacks p97 from cellular ERAD to benefit its replication. These findings add to our understanding of how viruses disturb ERAD and provide potential anti-viral targets for EV71 infection. [ABSTRACT FROM AUTHOR]

Purpose: Insulin-like growth factor 1 (IGF1) gene single nucleotide polymorphism (rs5742612) has been associated with adolescent idiopathic scoliosis (AIS) in several studies with limited sample size and inconsistent outcomes. So we perform this meta-analysis to assess the precise association between IGF1 gene single nucleotide polymorphism (rs5742612) and AIS.Methods: We systematically searched Pubmed, Embase, Web of Science and Cochrane Library up to January 19, 2016 to obtain relevant studies using our research strategy. Four articles all belonging to case-control studies were included in our meta-analysis.Results: A total of four studies containing 763 cases and 559 controls satisfied the inclusion criteria after judgment by two reviewers. No significant associations were detected between IGF1 gene single nucleotide polymorphism (rs5742612) and AIS (T vs. C, OR = 1.10, 95 % CI 0.91-1.34, p = 0.32; TT vs. CC: OR = 1.28, 95 % CI 0.82-2.02, p = 0.28; TC vs. CC: OR = 1.29, 95 % CI 0.82-2.06, p = 0.27; TT/TC vs. CC: OR = 1.28, 95 % CI 0.83-1.98, p = 0.27; TT vs.Tc/cc: OR = 1.06, 95 % CI 0.82-1.36, p = 0.66).Conclusions: IGF1 gene single nucleotide polymorphism (rs5742612) is not significant associated with susceptibility to AIS in either Asian or Caucasian populations. However, IGF1 gene rs5742612 may be associated with severity of AIS. Further studies with larger sample size and different population groups involving the relationship are required to confirm the potential association. [ABSTRACT FROM AUTHOR]