Age, growth, mortality and recruitment of thin sharpbelly Toxabramis swinhonis Günther, 1873 in three shallow lakes along the middle and lower reaches of the Yangtze River basin, China

Despite being the most dominant and widespread small fish species in the lakes along the middle and lower reaches of the Yangtze River basin, Toxabramis swinhonis has been paid little attention by fisheries scientists and little is known about its population characteristics. For this reason, we estimated age, growth, mortality and recruitment of this species based on three shallow lakes, Biandantang Lake, Shengjin Lake and Kuilei Lake (BDT, SJH and KLH, respectively) in this region. A total of 13,585 (8,818 in BDT, 2,207 in SJH and 2,560 in KLH) individuals were collected during monthly sampling from July 2016 to September 2017. The results revealed that the age structures of T. swinhonis consisted of four age groups (0+–3+), with 0+–1+ year old fish comprising more than 98% of the samples. Allometric growth patterns were displayed by fish from all sampling sites and the von Bertalanffy growth functions estimated were Lt = 173.25 (1 – e−1.20 (t + 1.09)): BDT; Lt = 162.75 (1 – e−1.20 (t + 1.08)): SJH and Lt = 215.25 (1 – e−1.20 (t + 1.12)): KLH, respectively. The rates of total mortality (Z), natural mortality (M) and fishing mortality (F) at BDT, SJH and KLH were computed as 5.82, 5.50 and 4.55 year−1; 1.89, 1.87 and 1.75 year−1; 3.93, 3.63 and 2.80 year−1, respectively. Meanwhile, growth performance indices (φ′) were 0.68 (in BDT), 0.66 (in SJH) and 0.62 (in KLH), which indicated that T. swinhonis were overfished slightly in all study areas. Area-specific recruitment patterns were similar to each other, displaying evidence of batch spawning, with major peaks in April and August, accounting for 92.21% (BDT), 88.21% (SJH) and 88.73% (KLH) of total recruitment, respectively. These results showed that brief generation-time, fast growth rate, relatively high natural mortality rate and strong reproductive capacity (r-strategies) are reasons why this species became the most dominant species in many lakes of China

An Analysis of the Present Situation of Migrant Workers' Education and Training——Taking Zhejiang as an Example

The education and training of migrant workers is an important way to improve the human capital and quality of migrant workers, is necessary for industrial transformation and upgrading, and is the key to solving issues concerning agriculture, countryside and farmers. Taking the developed coastal province of Zhejiang Province as an example, this paper analyzes the situation of migrant workers' education and training on employment transfer, the characteristics of migrant workers' education and training, and the problems existing in migrant workers' education and training, and puts forward some recommendations. On this basis, some conclusions are drawn

Industrial Upgrade, Vocational Ability and Migrant Worker Education and Training

Economic structure adjustment, industrial upgrade, and demands of migrant workers for vocational ability are direct driving factors for migrant workers participating in education and training. Personal quality of migrant workers not only concerns their survival and development, but also concerns upgrade of modern industrial structure. From the perspective of industrial upgrade, vocational ability and mechanism of migrant worker education and training, this paper analyzed difficulties in migrant worker education and training. On the basis of the difficulties, it came up with some strategies and recommendations

Economic Analysis on Migrant Workers’ Education and Training from the Perspective of Supply and Demand

The education and training are important methods to improve the quality of migrant workers and the key to solve the issues concerning agriculture, farmer and rural area. Based on theoretical and literature analysis, this paper analyzed economic problems in the education and training of migrant workers from the perspective of supply and demand. And it is considered that the supply and demand of migrant workers’ education and training are affected by many factors and present a certain economic phenomenon. And then it discussed the market failure problem of effective supply and demand for migrant workers’ current education and training based on the above

Overexpression of the Mas1 gene mitigated LPS-induced inflammatory injury in mammary epithelial cells by inhibiting the NF-κB/MAPKs signaling pathways

Breast infection is the primary etiology of mastitis in dairy cows, leading to a reduction in the quality of dairy products and resulting in substantial economic losses for animal husbandry. Although antibiotic treatment can eliminate the pathogenic microorganisms that induce mastitis, it cannot repair the inflammatory damage of mammary epithelial cells and blood milk barrier. Mas1 is a G protein-coupled receptor, and its role in lipopolysaccharide (LPS) -induced inflammatory injury to mammary epithelial cells has not been studied. LPS treatment of EpH4 EV cells led to a significant downregulation of Mas1 transcript levels, which attracted our great interest, suggesting that Mas1 may be an important target for the treatment of mastitis. Therefore, this study intends to verify the role of Mas1 in the inflammatory injury of EpH4 EV cells by gene overexpression technology and gene silencing technology. The findings demonstrated that the overexpression of the Mas1 gene effectively reversed the activation of the nuclear factor-κB/mitogen-activated protein kinase (NF-κB/MAPK) signaling pathways induced by LPS, while also suppressing the upregulation of pro-inflammatory mediators. Furthermore, overexpression of the Mas1 gene reversed the downregulation of zonula occludens 1 (ZO-1), Occludin, and Claudin-3 caused by LPS, suggesting that Mas1 could promote to repair the blood-milk barrier. However, the silencing of the Mas1 gene using siRNA resulted in a contrasting effect. These results indicated that Mas1 alleviated the inflammatory injury of mammary epithelial cells induced by LPS

Anthropogenic activities and environmental filtering have reshaped freshwater fish biodiversity patterns in China over the past 120 years

International audienceOver the past centuries, freshwater fish introductions and extinctions have been the major environmental and ecological crises in various water bodies in China. However, consequences of such crises on freshwater fish biodiversity in China remain only partially or locally studied. Furthermore, identifications of relatively sensitive areas along with stressors (i.e., environmental and anthropogenic drivers) influencing freshwater fish biodiversity patterns are still pending. Taxonomic, functional, and phylogenetic facets of biodiversity can well describe and evaluate the underlying processes affecting freshwater fish biodiversity patterns under different dimensionalities. Here we thus evaluated temporal changes in these facets of freshwater fish biodiversity as well as a new developed biodiversity index, multifaceted changes in fish biodiversity, for over a century at the basin level throughout China using both alpha and beta diversity approaches. We also identified the drivers influencing the changes in fish biodiversity patterns using random forest models. The results showed that fish assemblages in Northwest and Southwest China (e.g., Ili River basin, Tarim basin, and Erhai Lake basin) experienced extreme temporal and multifaceted changes in the facets of biodiversity compared with other regions, and environmental factors (e.g., net primary productivity, average annual precipitation, and unit area) largely drove these changes. Since fish faunas in over 80% of China's water bodies covering more than 80% of China's surface were currently undergoing taxonomic, functional, and phylogenetic homogenization, targeted conservation and management strategies should be proposed and implemented, especially for the areas with relatively high changes in biodiversity

Spatial pattern and determinants of global invasion risk of an invasive species, sharpbelly Hemiculter leucisculus (Basilesky, 1855)

Invasive species have imposed huge negative impacts on worldwide aquatic ecosystems and are generally difficult or impossible to be eradicated once established. Consequently, it becomes particularly important to ascertain their invasion risk and its determinants since such information can help us formulate more effective preventive or management actions and direct these measures to those areas where they are truly needed so as to ease regulatory burdens. Here, we examined the global invasion risk and its determinants of sharpbelly (Hemiculter leucisculus), one freshwater fish which has a high invasive potential, by using species distribution models (SDMs) and a layer overlay method. Specifically, first an ensemble species distribution model and its basal models (developed from seven machine learning algorithms) were explored to forecast the global habitat-suitability and variables importance for this species, and then a global invasion risk map was created by combining habitat-suitability with a proxy for introduction likelihood (entailing propagule pressure and dispersal constraints) of exotic sharpbelly. The results revealed that (1) the ensemble model had the highest predictive power in forecasting sharpbelly&#39;s global habitat-suitability; (2) areas with high invasion risk by sharpbelly patchily spread over the world except Antarctica; and (3) the Human Influence Index (HII), rather than any of the bioclimatic variables, was the most important factor influencing sharpbelly&#39; future invasion. Based on these results, the present study also attempted to propose a series of prevention and management strategies to eliminate or alleviate the adverse effects caused by this species&#39; further expansion. (C) 2019 Elsevier B.V. All rights reserved.</p

Base composition, adaptation, and evolution of goose astroviruses: codon-based investigation

ABSTRACT: Goose astroviruses (GoAstVs) are causative agents that account for fatal infection of goslings characterized by visceral urate deposition, resulting in severe economic losses in major goose-producing regions in China since 2017. In this study, we sought to unravel the intrinsic properties associated with adaptation and evolution in the host environment of GoAstVs. Consistent results from phylogenetic analysis and correspondence analysis performed on the codon usage patterns (CUPs) reveal 2 clusters of GoAstVs, namely, GoAstV-1 and GoAstV-2. However, multiple similar compositional characteristics were found, despite the high divergence between GoAstV-1 and GoAstV-2. Studies on the base composition of GoAstVs reveal an A/U bias, indicating a compositional constraint, while natural selection prevailed in determining the CUPs in the virus genome based on our neutrality plot analysis, reflecting high adaptive pressure to fit the host environment. Codon adaptation index (CAI) analysis revealed a higher degree of fitness to the CUPs of the corresponding host for GoAstVs than avian influenza virus and betacoronaviruses, which may be a favorable factor contributing to the high pathogenicity and wide distribution of GoAstVs in goslings. In addition, GoAstVs were less adapted to ducks and chickens, with significantly lower CAI values than to geese, which may be a reason for the different prevalence of GoAstVs among these species. Extensive investigations on dinucleotide distribution revealed a significant suppression of the CpG and UpA motifs in the virus genome, which may facilitate adaptation to the host's innate immune system by evading surveillance. In addition, our study reported the trends of increasing fitness to the host's microenvironment for GoAstVs through increasing adaptation to host CUPs and ongoing reduction of CpG motifs in the virus genome. The present analysis deepens our understanding of the basic biology, pathogenesis, adaptation and evolutionary pattern of GoAstVs, and contributes to the development of novel antiviral strategies

Effect of Puerarin, Baicalin and Berberine Hydrochloride on the Regulation of IPEC-J2 Cells Infected with Enterotoxigenic Escherichia coli

Puerarin, baicalin and berberine hydrochloride are the main components of Gegen Qinlian Decoction, which has been used to treat diarrhoea in China for hundreds of years, yet the biological function and molecular mechanism of these components are not clear. To investigate the effects of puerarin, baicalin, and berberine hydrochloride on the regulation of porcine intestinal epithelial cells (IPEC-J2 cells) infected with enterotoxigenic Escherichia coli (ETEC). IPEC-J2 cells were pretreated with puerarin (200 μg/mL), baicalin (1 μg/mL), and berberine hydrochloride (100 μg/mL) at 37°C for 3 h and then coincubated with the F4ac ETEC bacterial strain 200 at 37°C for 3 h. ETEC infection damaged the structure of IPEC-J2 cells, upregulated mucin 4 (P < 0.01) and mucin 13 mRNA (P < 0.05) expression, increased the apoptosis rate (P < 0.05), and promoted inflammatory responses (IL-6 and CXCL-2 mRNA expression) in IPEC-J2 cells by activating the nuclear factor-κB (NF-κB) signaling pathway. Pretreatment with puerarin, baicalin, and berberine hydrochloride improved the structure and morphology of IPEC-J2 cells and inhibited ETEC adhesion by downregulating specific adhesion molecules. Pretreatment with baicalin decreased the inflammatory response; pretreatment with baicalin and berberine hydrochloride decreased the inflammatory response mediated by the NF-κB signaling pathway. Pretreatment with puerarin, baicalin, and berberine hydrochloride protected IPEC-J2 cells from ETEC infection by inhibiting bacterial adhesion and inflammatory responses

Research progress on pharmacological effects and new dosage forms of baicalin

Abstract Background As a kind of flavonoid, baicalin (C21H18O11) is extracted from Scutellaria baicalensis Georgi, the extract of which can be added to animal feed in China. Objectives The present review will describe the current understanding of the pharmacological effects of baicalin in the regulation of inflammation, oxidative stress anti‐virus and anti‐tumour responses. Methods We highlight emerging literature that the application in livestock health and performance, the biological activities, the molecular mechanisms and the dosage forms of baicalin by analysing and summarising the main points of the cited literatures. Results It is found that baicalin can improve the functions of multiple physiological systems. Baicalin has a strong anti‐inflammatory effect by regulating TLR4‐NFκB‐MAPK signalling pathway; it also can reduce oxidative stress by regulating Nrf2–Keap1 pathway; it can inhabit many kinds of virus such as influenza virus, respiratory virus, hepacivirus and others; it can also inhibit the growth of tumour cells by blocking the cell cycle or inducing apoptosis; and new dosage forms such as cationic solid lipid nanoparticles, cyclodextrin inclusion complexes or nanocrystalline can be applied to improve the deficiency of baicalin. Conclusions In summary, these studies have elucidated a comprehensive report on the anti‐inflammatory, anti‐oxidant, anti‐virus and anti‐tumour of baicalin, these findings thus indicated that baicalin can be used effectively to the field of animal production in future when the appropriate dosage form is determined