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Atypical porcine pestivirus (APPV) was identified and associated with congenital tremor (CT) type A‐II in new born piglets and has been reported in many countries. In China, the first APPV identification in swine herds was reported in Guangdong province in 2016. To investigate the genetic characteristics of APPV in Guangxi province, 53 tissue samples from neonatal piglets with CT were collected and detected from October 2017 to May 2019. Five APPV strains which were named as GX04/2017, GX01‐2018, GX02‐2018, GX01‐2019 and GX02‐2019 were obtained. Sequence analysis revealed that all six APPV strains from Guangxi province, including five strains from this study and one from a previous report, shared 83.3%‐97.5% nucleotide identity of complete genome and 91.7%‐99.1% amino acid identity of the open reading frame (ORF), and shared 77.7%‐97.7% nucleotide identity of complete genome and 90.6%‐99.3% amino acid identity of ORF with reference strains. Phylogenetic analysis indicated that all APPV strains could be divided into three clades based on the complete genome, Npro, Erns and E2 gene sequences, respectively; and the APPV strains from Guangxi province distributed in two clades (clades I and II). No sign of recombination was observed from Guangxi strains. Evolution analysis performed on the complete genome of 58 APPV strains showed that America, Europe and Asia strains during 2006–2019 evolved at a mean rate of 1.37 × 10–4 substitutions/site/year, and the most recent common ancestor (tMRCA) of them was estimated as 1,700.5 years ago. The findings of this study indicated that there existed a high degree of genetic diversity of APPV from Guangxi province, Southern China, which provided important information on the epidemiological features and evolutionary relationships of APPV. [ABSTRACT FROM AUTHOR]

Long-term and continuous observations of mesospheric/lower thermospheric winds are rare, but they are important to investigate climatological changes at these altitudes on time scales of several years, covering a solar cycle and longer. Such long time series are a natural heritage of the mesosphere/lower thermosphere climate, and they are valuable to compare climate models or long term runs of general circulation models (GCMs). Here we present a climatological comparison of wind observations from six meteor radars at two conjugate latitudes to validate the corresponding mean winds and atmospheric diurnal and semidiurnal tides from three GCMs, namely Ground-to-Topside Model of Atmosphere and Ionosphere for Aeronomy (GAIA), Whole Atmosphere Community Climate Model Extension (Specified Dynamics) (WACCM-X(SD)) and Upper Atmosphere ICOsahedral Non-hydrostatic (UA-ICON) model. Our results indicate that there are interhemispheric differences in the seasonal characteristics of the diurnal and semidiurnal tide. There also are some differences in the mean wind climatologies of the models and the observations. Our results indicate that GAIA shows a reasonable agreement with the meteor radar observations during the winter season, whereas WACCM-X(SD) shows a better agreement with the radars for the hemispheric zonal summer wind reversal, which is more consistent with the meteor radar observations. The free running UA-ICON tends to show similar winds and tides compared to WACCM-X(SD). [ABSTRACT FROM AUTHOR]

Thermosphere cooling is a known effect of increasing CO2 in the atmosphere. In this study, we explore the changes of thermosphere circulation and tides in the cooled thermosphere via a doubled CO2 numerical experiment using the Ground‐to‐topside Atmosphere Ionosphere model for Aeronomy (GAIA). The results reveal three major features. (1) The thermosphere cools about 10 K more around solstices than equinoxes, more at the summer pole than the winter pole. (2) The meridional circulation shifts downward and strongly accelerates by 5–15 m s−1. (3) The tidal activity experiences dramatic changes, with a 40–60% reduction in the semidiurnal tides (SW2) throughout the thermosphere but an 30–50% enhancement in diurnal tides (DW1) below 200 km altitude. The nonmigrating tide DE3 has only minor changes. These changes in temperature, meridional circulation, and tides are persistent features in all seasons and can profoundly affect the spatial distribution and diurnal cycles of the ionospheric responses to CO2 doubling via atmosphere composition and electrodynamics. Key Points: Thermosphere cooling is stronger around solstice than equinoxesThe meridional circulation is accelerated by 5–15 m/sSemidiurnal tides are strongly reduced [ABSTRACT FROM AUTHOR]

Flame retardants, especially Tetrachlorobisphenol A (TCBPA), one of the waste materials from renewable energy devices, are becoming a significant environmental concern. While pyrolysis has emerged as a promising method for the disposal of TCBPA-containing waste, the complex molecular mechanisms and reaction pathways involved in TCBPA pyrolysis remain largely unknown. In this work, an integrated approach combining Reactive force field molecular dynamics (ReaxFF-MD), Density Functional Theory (DFT), and thermogravimetric-Mass Spectroscopy (TG-MS) techniques was employed to scrutinize TCBPA pyrolysis at the microscopic level. ReaxFF-MD simulations were performed to investigate the pyrolysis process over a wide temperature range (2200–3200 K), revealing complex pyrolysis mechanisms with multiple reaction pathways, including β-scission, dechlorination, dehydrogenation, dehydroxylation, and the formation of chlorinated products, such as HCl, C 2 HCl, and CH 3 Cl. The primary gaseous by-products detected in the TCBPA pyrolysis align with the results from ReaxFF simulations. The computational outcomes reveal that the primary reaction sites in TCBPA pyrolysis are B 1 (bridgehead carbon) and B 2 (chloro-substituted carbon), collectively representing roughly 80 % of total reactions. The DFT results show that hydrogen and chlorine detachments from various functional groups have distinct energy requirements, contingent upon specific energy barriers. Additionally, minor coking events occur during pyrolysis, leading to marginal tar and char production, which is temperature dependent. The pyrolysis pathways of TCBPA were unraveled and the potential environmental hazards associated with chlorinated organic pollutant byproducts, such as HCl, were highlighted. The fundamental knowledge obtained from this study provides insights and guidance for the disposal of TCBPA-containing waste in an environmentally friendly manner. • Integrated ReaxFF-MD, DFT, and TG-MS approach for detailed TCBPA pyrolysis analysis. • Identified B 1 and B 2 as primary reaction sites, accounting for 80 % of reactions. • The reaction frequencies detailed, highlighting β-scission and dechlorination. • Major gaseous by-products during TCBPA pyrolysis matched ReaxFF simulation outcomes. • Detailed energy barriers for hydrogen and chlorine detachments revealed through DFT. [ABSTRACT FROM AUTHOR]