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Simple Summary: We developed the DAS–ELISA to investigate the infection and prevalence of GyH1 in chickens and wild birds in China. We found that natural GyH1 infections were widespread in chickens and wild birds. Importantly, young chickens are more susceptible to GyH1, and local chicken species in China are genetically resistant to GyH1. In particular, we found a significantly higher GyH1–positive rate in wild birds than in chickens, implying that there may be a risk of GyH1 transmission from wild birds to chickens. Gyrovirus homsa1 (GyH1) is an emerging pathogenic single–stranded circular DNA virus that leads to immunosuppression, aplastic anemia, and multisystem damage in chickens. However, the prevalence of GyH1 infection in chickens and wild birds remains unknown. Here, we developed a double–antibody sandwich enzyme–linked immunosorbent assay (DAS–ELISA) to investigate GyH1 infection in 8 chicken species and 25 wild bird species. A total of 2258 serum samples from chickens (n = 2192) in 15 provinces, and wild birds (n = 66) in Jinan Wildlife Hospital were collected from 2017 to 2021 in China. The GyH1–positive rates in chickens and wild birds were 9.3% (203/2192) and 22.7% (15/66), respectively. GyH1 was present in all flocks in 15 provinces. From 2017 to 2021, the positive rate ranged from 7.93% (18/227) to 10.67% (56/525), and the highest positive rate was present in 2019. Upon chicken age, the highest positive rate (25.5%) was present in young chickens (14–35 days old). Moreover, the GyH1–positive rate in broiler breeders (12.6%, 21/167) was significantly higher than that in layer chickens (8.9%, 14/157). This study shows that GyH1 has spread in chicken flocks and wild birds, and the higher GyH1–positive rate in wild birds indicates the risk of spillover from wild birds to chickens. Our study expanded the GyH1 epidemiological aspects and provided a theoretical basis for GyH1 prevention. [ABSTRACT FROM AUTHOR]

Rain height is crucial for rain attenuation prediction along slant paths, such as Earth-space links. The global digital map of the mean annual rain height is given in Recommendation ITU-R P.839-4. The disadvantage of this model is that heavy rainfall in most regions of the middle and high latitudes of the world is typically concentrated over a few months, such as summer in North China, and the mean rain height during these months and the mean annual rain height are often significantly different. In this study, a new weighted mean annual rain height is proposed by using the ratio of the mean monthly rainfall to the mean annual rainfall as the weight. The analysis shows that the weighted mean annual rain heights have been closer to the statistical rain heights during heavy rainfall in general. On the other hand, the work of this paper helps to improve the accuracy of the rain attenuation prediction model on Earth-space links in China. However, the weighted mean annual rain heights have different characteristics for different rainfall climate zones. This study will contribute to the research of rain attenuation modelling on Earth-space links. [ABSTRACT FROM AUTHOR]

Background: Transmissible viral proventriculitis (TVP) causes significant economic loss to the poultry industry. However, the exact causative agents are obscure. Here we examine the virome of proventriculus from specified pathogen free (SPF) chickens that reproduced by infection of proventricular homogenate from broiler chicken with TVP using long read sequencing of the Pacific Biosciences RSII platform. The normal SPF chickens were used as control. Results: Our investigation reveals a virome of proventriculitis, including three Gyrovirus genera of the Aneloviridae: Gyrovirus homsa1 (GyH1) (also known as Gyrovirus 3, GyV3) (n = 2662), chicken anemia virus (CAV) (n = 482) and Gyrovirus galga1 (GyG1) (also known as avian Gyrovirus 2, AGV2) (n = 11); a plethora of novel CRESS viral genomes (n = 26) and a novel genomovirus. The 27 novel viruses were divided into three clusters. Phylogenetic analysis showed that the GyH1 strain was more closely related to the strains from chicken (MG366592) than mammalian (human and cat), the GyG1 strain was closely related to the strains from cat in China (MK089245) and from chicken in Brazil (HM590588), and the CAV strain was more closely related to the strains from Germany (AJ297684) and United Kingdom (U66304) than that previously found in China. Conclusion: In this study, we revealed that Gyrovirus virome showed high abundance in chickens with TVP, suggesting their potential role in TVP, especially GyH1. This study is expected to contribute to the knowledge of the etiology of TVP. [ABSTRACT FROM AUTHOR]

Background: Gyrovirus homsa1 (GyH1) (also known as Gyrovirus 3, GyV3) is a non-enveloped, small, single-stranded DNA virus, which was first identified in children with acute diarrhea, and was subsequently detected in marketed chickens, broilers with transmissible viral proventriculitis (TVP), and mammals. GyH1 is a pathogenic virus in chickens, causing aplastic anemia, immunosuppression, and multisystem damage. However, the seroepidemiology of GyH1 infection in chickens remains unclear. Here, we investigated the seroprevalence of GyH1 in chickens by ELISA to reveal the endemic status of GyH1 in China. Results: An indirect ELISA with high sensitivity and specificity was developed for investigation of seroepidemiology of GyH1 in chickens in China. The seropositive rate of GyH1 ranged from 0.6% to 7.7% in thirteen provinces, and ranged from 4.1% to 8.1% in eight species chickens. The seropositive rate of GyH1 in broiler breeders was significantly higher than that of in layers. There was a negative correlation between seropositive rate and age of chickens. The highest and lowest seropositive rate were present in chickens at 30–60 days and over 180 days, respectively. Conclusions: The seroepidemiological investigation results demonstrated that natural GyH1 infection is widespread in chickens in China. Different species showed different susceptibility for GyH1. Aged chickens showed obvious age-resistance to GyH1. GyH1 has shown a high risk to the poultry industry and should be highly concerned. [ABSTRACT FROM AUTHOR]

Mitochondrial cytochrome b (Cytb) and partial control region (CR) DNA sequence of 165 individuals out of eight pig breeds (Laiwu Black, Dapulian Black, Licha Black, Yimeng Black, Yantai Black, Wulian Black, Luyan White and Changwei White) from Shandong province of China were sequenced to determine phylogenetic relationships and to what extent they were affected by modern commercial breeds (Landrace, Yorkshire and Duroc) in maternal lineage. The eight breeds from Shandong had lower maternal evolutionary divergence than the three commercial breeds. Additionally, they shared the same haplotype (T2) of Cytb. All these results suggest they may have originated from closely related maternal ancestors, if not from a single ancestor. The fact that haplotypes of Dapulian Black and Laiwu Black formed their own subclades, while those of other breeds of Shandong dispersed in the Asian clade of the tree based on CR, indicates that Dapulian Black and Laiwu Black are indigenous breeds with relatively independent maternal lineage, while the others have extensively gene flow with other breeds. Except in Luyan White, no European haplotypes were found in pig breeds from Shandong, demonstrating the maternal introgression from the modern commercial pigs has had no or very little impact on the breeds from Shandong. Comparatively, CR is more suitable to analyze the phylogenetic relationships of closely related groups, whereas the four SNPs of Cytb are useful to determine whether modern commercial breeds (Duroc, Landrace and sometimes Yorkshire) were used as dam in the breeding process of new breeds or synthetic lines in China. [ABSTRACT FROM AUTHOR]

[Display omitted] • Aeration sponge iron biofilter (SIBF) achieved autotrophic nitrogen removal of 77.2%. • The optimal operation condition of SIBF was HRT of 9 and gas–water ratio (R) of 9:1. • Autotrophic nitrogen removal paths included nitrification, Feammox, NDFO and Anammox. • Nitrisomonas and Thiobacillus as autotrophic nitrifier/denitrifier played major roles. Partial nitrification and anammox process is considered to be a good choice for nitrogen removal. Nevertheless, it is difficult to achieve in low ammonia wastewater because of the need to control further oxidation of nitrite. Nitrification combined with Feammox (anaerobic ammonia oxidation coupled to Fe (III) reduction) and NDFO (nitrate/nitrite-dependent Fe (II) oxidation) can achieve autotrophic removal of low ammonia. And sponge iron can avoid the disadvantage of continuously adding iron sources in this process. Therefore, a sponge iron biofilter (SIBF) treating low ammonia wastewater under aeration was explored in this study. The optimal operating conditions for SIBF were hydraulic retention time (HRT) of 9 h and gas–water ratio (R) of 9:1, at which the total inorganic nitrogen removal efficiency was up to 77.2 %, and effluent ammonia and total inorganic nitrogen concentrations were less than 5 mg/L and 15 mg/L, respectively. This met the 1A discharge standard of municipal wastewater in China. Stable ratio isotope results indicated that Feammox, NDFO and Anammox resulted in high nitrogen loss in SIBF. And different nitrogen transformation contribution tests indicated NDFO had the dominant contribution, which accounted for 55.7 %. Besides, the production of N 2 O was minimum under HRT of 9 h and R of 9:1, in which the N 2 O emission factor was 0.7 %. Stable isotope tracing analysis showed that 92.8 % of N 2 O was derived from ammonia and the dominant production pathway was nitrifier denitrification. The results of microbial community showed that the nitrification bacteria- Nitrosomonas , Nitrotoga , Nitrospira , Feammox bacteria- Dechloromonas , NDFO bacteria- Thiobacillus and anammox bacteria- Brocadia played major roles in SIBF. Therefore, SIBF shows superior performance and application potential in autotrophic nitrogen removal from low-ammonia nitrogen wastewater under aeration. [ABSTRACT FROM AUTHOR]

Haze pollution in China is a serious environmental issue, which does harm both to people's health and to economic development. Simultaneously, as an important industrial development law, agglomeration may result in the increased concentration of manufacturing firms and, consequently, an increase in haze pollution. However, the positive externalities of agglomeration can also improve the efficiency of regional innovation, which curbs haze pollution. In this paper, we construct both theoretical and empirical models to investigate the effects of industrial manufacturing agglomeration on haze pollution. The results reveal the following: (1) By incorporating the effect of agglomeration and haze pollution into a general endogenous growth model, we show an inverted-U relationship between agglomeration and haze pollution on the balance growth path. (2) Based on data concerning haze pollution (PM 2.5 ) and data from 285 Chinese cities, the empirical results verify the findings of the theoretical model. Further, we calculated the values of agglomeration variables, with respect to the inflection points of the inverted-U, which the cities need to reach in order to gain the specific agglomeration values required to enjoy the inhibition effect of agglomeration on haze pollution. (3) A heterogeneity analysis shows that the inverted-U relationship is more obvious among the cities in the middle and northeastern areas of China, as well as medium-size cities. (4) Cities' environmental regulation policies and high-quality institutional environments can restrain the positive effect of agglomeration on haze pollution. (5) Using three measures of innovation, it is also empirically found that innovation is the mechanism (mediator) between agglomeration and haze pollution.