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The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has shown once again that coronavirus (CoV) in animals are potential sources for epidemics in humans. Porcine deltacoronavirus (PDCoV) is an emerging enteropathogen of swine with a worldwide distribution. Here, we implemented and described an approach to analyze the epidemiology of PDCoV following its emergence in the pig population. We performed an integrated analysis of full genome sequence data from 21 newly sequenced viruses, along with comprehensive epidemiological surveillance data collected globally over the last 15 years. We found four distinct phylogenetic lineages of PDCoV, which differ in their geographic circulation patterns. Interestingly, we identified more frequent intra- and interlineage recombination and higher virus genetic diversity in the Chinese lineages compared with the USA lineage where pigs are raised in different farming systems and ecological environments. Most recombination breakpoints are located in the ORF1ab gene rather than in genes encoding structural proteins. We also identified five amino acids under positive selection in the spike protein suggesting a role for adaptive evolution. According to structural mapping, three positively selected sites are located in the N-terminal domain of the S1 subunit, which is the most likely involved in binding to a carbohydrate receptor, whereas the other two are located in or near the fusion peptide of the S2 subunit and thus might affect membrane fusion. Finally, our phylogeographic investigations highlighted notable South-North transmission as well as frequent long-distance dispersal events in China that could implicate human-mediated transmission. Our findings provide new insights into the evolution and dispersal of PDCoV that contribute to our understanding of the critical factors involved in CoVs emergence.

【Objective】 Evapotranspiration (ET) is an important hydrological component and parameter for agricultural management. It varies with both plantations and meteorological factors. In this paper, we studied the effect of climate change and leaf area index (LAI) on ET, as well as the seasonal variation in crop coefficient of kiwifruit orchards in southwest China. 【Method】 The study was based on field experiments. The Penman-Monteith model using data measured in 2018 and 2019 was used to calculate the potential ET, from which we analyzed the mechanisms underlying the near-surface water vapor flux. The sensitivity of ET to various meteorological factors was also calculated, and the real ET was calculated using a single crop coefficient (Kc) and dual crop coefficient (Kcb), respectively. 【Result】 ①In 2018 and 2019, the average daily ET was 2.71 mm/d and 2.23 mm/d respectively, the aerodynamic term in ET was1.87 mm/d and 1.71 mm/d, respectively, accounting for 0.69 and 0.74 of the total ET. ②During the growth period of the kiwifruit in both 2018 and 2019, ET was most sensitive to VPD, followed by rc、Rn-G、ra. ③In both 2018 to 2019, Kc increased first followed by a fall as the plant grew, while the Kcb increased in the late growth stage. The average Kc in 2018 and 2019 was 0.93 and 0.85, and its associated average Kcb was 0.43 and 0.41, respectively. 【Conclusion】 Our results show that the aerodynamic term was the main factor affecting ET in the kiwifruit orchard, while the ET was most sensitive to VPD.

Swine acute diarrhea syndrome coronavirus (SADS-CoV), a member of the family Coronaviridae and the genus Alphacoronavirus, primarily affects piglets under 7 days old, causing symptoms such as diarrhea, vomiting, and dehydration. It has the potential to infect human primary and passaged cells in vitro, indicating a potential risk of zoonotic transmission. In this study, we successfully generated and purified six monoclonal antibodies (mAbs) specifically targeting the spike protein of SADS-CoV, whose epitope were demonstrated specificity to the S1A or S1B region by immunofluorescence assay and enzyme-linked immunosorbent assay. Three of these mAbs were capable of neutralizing SADS-CoV infection on HeLa-R19 and A549. Furthermore, we observed that SADS-CoV induced the agglutination of erythrocytes from both humans and rats, and the hemagglutination inhibition capacity and antigen–antibody binding capacity of the antibodies were assessed. Our study reveals that mAbs specifically targeting the S1A domain demonstrated notable efficacy in suppressing the hemagglutination phenomenon induced by SADS-CoV. This finding represents the first instance of narrowing down the protein region responsible for SADS-CoV-mediated hemagglutination to the S1A domain, and reveals that the cell attachment domains S1A and S1B are the main targets of neutralizing antibodies. [ABSTRACT FROM AUTHOR]

Foam-assisted gas injection exhibits promising potential for enhancing sweep efficiency through the amelioration of gravity segregation, particularly within reservoirs characterized by heterogeneity. In this work, the implicit-texture (IT) model featuring two flow regimes is employed to examine the impact of heterogeneity on gravity segregation. The validation of the numerical results for water–gas coinjection and pre-generated foam injection is accomplished through a comparative analysis with analytical solutions. A hypothetical two-layer model with varying permeabilities and thickness ratios is used to examine the impact of foam on gravity segregation. The numerical findings demonstrate satisfactory conformity with analytical solutions in homogeneous reservoirs. A high-permeability top layer in a layered model with a fixed injection rate results in sweep efficiency similar to that of a homogeneous reservoir with each individual permeability. A low-permeability top layer could increase the sweep efficiency, but with severe permeability contrast, the bottom high-permeability layer could impact the displacement process, even with a thin thickness. The sweep efficiency increases with the thickness of the high-permeability top layer and decreases with a thicker low-permeability top layer under fixed injection pressure. The predicted segregation length through a single-layer approximation cannot match the results of the layered models where the permeability contrast is too great or the thickness of two layers is comparable. [ABSTRACT FROM AUTHOR]