scholarly journals Epidemiology and Evolution of Emerging Porcine Circovirus-like Viruses in Pigs with Hemorrhagic Dysentery and Diarrhea Symptoms in Central China from 2018 to 2021

Viruses ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 2282
Author(s):  
Kankan Yang ◽  
Menghuan Zhang ◽  
Qi Liu ◽  
Yingli Cao ◽  
Wuyin Zhang ◽  
...  

Porcine circovirus-like virus (PCLV) is a type of circular Rep-encoding single-stranded DNA virus and may be associated with the development of diarrheal symptoms in pigs. In this study, we retrospectively analyzed three years of past cases in Anhui, China, and reported a case of hemorrhagic enteritis and death in a pregnant sow possibly caused by PCLV. In addition, we analyzed the evolutionary characteristics of PCLV and found that mutation, recombination and selective pressure all played an important role in the evolution of PCLV. We identified N15D and T17S as well as L56T, T58R, K59Q, M62R, L75I and R190K mutations in two different branches, and we noted recombination events in the Rep of a group of Chinese strains. Analysis of selection pressure revealed that PCLV gained more positive selection, indicating that the virus is in a continuous evolutionary state. The PR2 plot, ENC-plot and neutrality analysis showed a greater role of natural selection than that of mutational pressure in the formation of codon usage patterns. This study is the first to identify PCLV in sows with hemorrhagic dysentery and death, and it provides new epidemiological information on PCLV infection in pigs in China.

2005 ◽  
Vol 201 (11) ◽  
pp. 1709-1714 ◽  
Author(s):  
David G. Bowen ◽  
Christopher M. Walker

The mechanisms by which the hepatitis C virus (HCV) establishes persistence are not yet fully understood. Previous chimpanzee and now human studies suggest that mutations within MHC class I–restricted HCV epitopes might contribute to viral escape from cytotoxic T lymphocyte (CTL) responses. However, there are several outstanding questions regarding the role of escape mutations in viral persistence and their fate in the absence of immune selection pressure.


2016 ◽  
Vol 283 (1825) ◽  
pp. 20152890 ◽  
Author(s):  
John Skelhorn ◽  
Candy Rowe

Camouflage is one of the most widespread forms of anti-predator defence and prevents prey individuals from being detected or correctly recognized by would-be predators. Over the past decade, there has been a resurgence of interest in both the evolution of prey camouflage patterns, and in understanding animal cognition in a more ecological context. However, these fields rarely collide, and the role of cognition in the evolution of camouflage is poorly understood. Here, we review what we currently know about the role of both predator and prey cognition in the evolution of prey camouflage, outline why cognition may be an important selective pressure driving the evolution of camouflage and consider how studying the cognitive processes of animals may prove to be a useful tool to study the evolution of camouflage, and vice versa. In doing so, we highlight that we still have a lot to learn about the role of cognition in the evolution of camouflage and identify a number of avenues for future research.


2011 ◽  
Vol 57 (12) ◽  
pp. 1016-1023 ◽  
Author(s):  
Xue Lian Luo ◽  
Jian Guo Xu ◽  
Chang Yun Ye

In this study, we analysed synonymous codon usage in Shigella flexneri 2a strain 301 (Sf301) and performed a comparative analysis of synonymous codon usage patterns in Sf301 and other strains of Shigella and Escherichia coli . Although there was a significant variety in codon usage bias among different Sf301 genes, there was a slight but observable codon usage bias that could primarily be attributable to mutational pressure and translational selection. In addition, the relative abundance of dinucleotides in Sf301 was observed to be independent of the overall base composition but was still caused by differential mutational pressure; this also shaped codon usage. By comparing the relative synonymous codon usage values across different Shigella and E. coli strains, we suggested that the synonymous codon usage pattern in the Shigella genomes was strain specific. This study represents a comprehensive analysis of Shigella codon usage patterns and provides a basic understanding of the mechanisms underlying codon usage bias.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Jinqiang Wang ◽  
Yaobin Lu ◽  
Si Fan ◽  
Peng Hu ◽  
Bin Wang

PurposeThe purpose of the research is to explore how small and medium enterprises (SMEs) in central China achieve intelligent transformation through the use of artificial intelligence (AI). Because of unequal resource allocation, constraints on the intelligent transformation of SMEs in central China are different from those in economically and technologically well-developed coastal provinces. Hence, the authors focus on SMEs in central China to identify drivers of and barriers to intelligent transformation.Design/methodology/approachThe interview data were collected from 66 SMEs across 20 industries in central China. To verify the validity of the data collection method, the authors used two methods to control for retrospective bias: multi-level informants and enterprises' AI project application materials (Wei and Clegg, 2020). The final data were validated without conflicts. Next, the authors cautiously followed a two-step approach recommended by Venkatesh et al. (2010) and used NVivo 11.0 to analyze the collected text data.FindingsSMEs in central China are enthusiastic about intelligent transformation while facing both internal and external pressures. SMEs need to pay attention to both internal (enterprise development needs, implementation cost, human resources and top management involvement) and external factors (external market pressure, convenience of AI technology and policy support) and their different impacts on intelligent transformation. However, constrained by limited resources, SMEs in central China have been forced to take a step-by-step intelligent transformation strategy based on their actual needs with the technological flexibility method in the short term.Originality/valueConsidering the large number of SMEs and their importance in promoting China's economic development and job creation (SME Bureau of MIIT, 2020), more research on SMEs with limited resources is needed. In the study, the authors confirmed that enterprises should handle “social responsibility” carefully because over-emphasizing it will hinder intelligent transformation. However, firms should pay attention to the role of executives in promoting intelligent transformation and make full use of policy support to access more resources.


CATENA ◽  
2013 ◽  
Vol 109 ◽  
pp. 186-194 ◽  
Author(s):  
Chao Wang ◽  
Fuchun Li ◽  
Huanzhi Shi ◽  
Zhangdong Jin ◽  
Xuhui Sun ◽  
...  

Author(s):  
N. G. Rudova ◽  
V. I. Bolotin ◽  
O. S. Solodiankin ◽  
А. P. Gerilovych

Porcine circovirus type 2 (PCV2) is an emergent single-stranded DNA virus found all over the world in domestic pigs and wild boars that causes infectious disease with a great impact on swine productivity. PCV2 has 1.7 kb genome that includes two main genes, which encode replication-related protein (rep) and the major structural capsid (cap) protein. Both of these genes can be used as target sequences for the primer design for the detection of PCV2 as well as for sequencing of designated regions. We carried out a screening due to the PCV2 circulating among the wild boar population in 10 regions of Ukraine. PCR screening was performed using primer pairs designed on the target sequences of the replicative and capsid genes. According to the results of the research, the presence of genetic material of PCV2 was found in 31.8% of the tested samples. The developed set of primers may be suitable for diagnostics, as well as for the development of specific sites for the purpose of sequencing of PCV2 cap-gene due to the obtained DNA samples during epizootic screening


2021 ◽  
Vol 12 ◽  
Author(s):  
Hirotaka Imada ◽  
Nobuhiro Mifune

Disease-causing parasites and pathogens play a pivotal role in intergroup behavior. Previous studies have suggested that the selection pressure posed by pathogen threat has resulted in in-group assortative sociality, including xenophobia and in-group favoritism. While the current literature has collated numerous studies on the former, strikingly, there has not been much research on the relationship between pathogen threat and in-group cooperation. Drawing upon prior studies on the function of the behavioral immune system (BIS), we argued that the BIS might facilitate cooperation with in-group members as a reactive behavioral immune response to pathogen threat. More specifically, we held that individuals might utilize cooperative behavior to ensure that they can receive social support when they have contracted an infectious disease. We reviewed existing findings pertaining to the potential role of the BIS in in-group cooperation and discussed directions for future studies.


BMC Biology ◽  
2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Richard J. Harris ◽  
K. Anne-Isola Nekaris ◽  
Bryan G. Fry

Abstract Background Snakes and primates have a multi-layered coevolutionary history as predators, prey, and competitors with each other. Previous work has explored the Snake Detection Theory (SDT), which focuses on the role of snakes as predators of primates and argues that snakes have exerted a selection pressure for the origin of primates’ visual systems, a trait that sets primates apart from other mammals. However, primates also attack and kill snakes and so snakes must simultaneously avoid primates. This factor has been recently highlighted in regard to the movement of hominins into new geographic ranges potentially exerting a selection pressure leading to the evolution of spitting in cobras on three independent occasions. Results Here, we provide further evidence of coevolution between primates and snakes, whereby through frequent encounters and reciprocal antagonism with large, diurnally active neurotoxic elapid snakes, Afro-Asian primates have evolved an increased resistance to α-neurotoxins, which are toxins that target the nicotinic acetylcholine receptors. In contrast, such resistance is not found in Lemuriformes in Madagascar, where venomous snakes are absent, or in Platyrrhini in the Americas, where encounters with neurotoxic elapids are unlikely since they are relatively small, fossorial, and nocturnal. Within the Afro-Asian primates, the increased resistance toward the neurotoxins was significantly amplified in the last common ancestor of chimpanzees, gorillas, and humans (clade Homininae). Comparative testing of venoms from Afro-Asian and American elapid snakes revealed an increase in α-neurotoxin resistance across Afro-Asian primates, which was likely selected against cobra venoms. Through structure-activity studies using native and mutant mimotopes of the α-1 nAChR receptor orthosteric site (loop C), we identified the specific amino acids responsible for conferring this increased level of resistance in hominine primates to the α-neurotoxins in cobra venom. Conclusion We have discovered a pattern of primate susceptibility toward α-neurotoxins that supports the theory of a reciprocal coevolutionary arms-race between venomous snakes and primates.


Author(s):  
Paweł Mackiewicz ◽  
Przemysław Biecek ◽  
Dorota Mackiewicz ◽  
Joanna Kiraga ◽  
Krystian Baczkowski ◽  
...  

2016 ◽  
pp. 1447-1464
Author(s):  
Amir Manzoor

The Information Technology (IT) produces significant impact on the emotional and social health of young people. It is obvious that IT is playing an increasingly important part in people's lives. This chapter reviews the current state of youth health and the role of digital landscapes in health education of youth. The chapter also provides insight into how youth, particularly youth of color, use technology to learn, communicate, and discuss various health-related issues. Specific technology needs and usage patterns are identified and success of various initiatives of use of technology for health educations is assessed. Various implications and recommendations are provided for optimizing technology use in young people health education.


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