Abstract
This paper takes the level of high-quality agricultural development and ecological construction in 31 provinces of China from 2011 to 2021 as the research object. The coupling coordination ...degree model and Moran index are used to explore the coupling coordination stage, types and spatiotemporal evolution trend of agricultural high-quality development and ecological construction in China. The obstacle model is used to determine the key obstacle factors influencing the coupling development of high-quality agricultural and ecological construction in China. The results are as follows: from 2011 to 2021, high-quality agricultural development and ecological construction in 31 provinces maintained a relatively stable growth trend. However, the coupling coordination level between the two is low, and thus such level belongs to the high-quality development lag type of primary coordination agriculture. The agricultural externality index, land yield rate and per capita rural power generation are the biggest obstacles to the coordinated development of high-quality agricultural development and ecological construction in China.
The long-term and stable development of agriculture is the key to China's economic development and social stability. Agricultural total factor productivity and the digital economy have become new ...kinetic energy and new engines driving agricultural high-quality development. It is of great significance to verify whether there are significant spatial and threshold effects in the process of high-quality development of agriculture and to explore the intrinsic relationship between high-quality development of agriculture and agricultural total factor productivity and digital economy. This paper takes 31 provinces in China from 2011 to 2020 as the research object. The coefficient of variation method is used to estimate the comprehensive evaluation index of agricultural high-quality development and digital economy. And Dea-Malmquist index method is used to estimate agricultural total factor productivity. On this basis, the spatial Durbin model and threshold regression model are constructed to explore the spatial and threshold effects of agricultural total factor productivity, digital economy and other factors and high-quality agricultural development. The conclusion is as follows: the high-quality development of agriculture has significant spatial autocorrelation. Agricultural total factor productivity and digital economy have significant direct effect and indirect spillover effect on the high-quality development of agriculture. Agricultural total factor productivity has stage differences in each range of digital economy level, but its influence on agricultural high-quality development shows a positive state. Based on this, the paper puts forward some countermeasures to promote the high-quality development of agriculture.
•The energy flow through the soil nematode food webs of four ecosystems was evaluated.•Carbon flux may be determined by resource quantity rather than disturbance intensity.•The total carbon flux of ...the soil food web was positively correlated with the structure index, maturity index and genus diversity of the soil food web.•The carbon flux through the plant-energy channel was unaffected by the food web structure.
Energy flux in food webs is a fundamental feature of ecosystems and an important link between biodiversity and ecosystem function. Studies of energy flow through the soil nematode food web have emerged in recent year; however, it is not clear whether and how the nematode food web structure affects the energy flow. In this study, the structures and carbon flux of soil nematode food webs in four different ecosystems, namely, forageland, cropland, secondary forest, and grass-shrubland, were assessed. The food web structure was represented by nematode community indices such as maturity index, structure index, genus and trophic group diversity, and slope of size spectra. The results showed that carbon flux through the nematode food webs was the highest and lowest in the secondary forest and forageland, respectively. The total carbon flux of nematode food web was higher in the cropland than that in the grass-shrubland. The magnitudes of bacterial and fungal energy channels were basicallyequal in the forageland and secondary forest. The energy flow through the bacterial channel was greater than that through the fungal channel in the grass-shrubland, whereas the pattern was reversed in the cropland. The total carbon flux through the nematode food web, the carbon fluxes through the bacterial or fungal channel, and the energy flow uniformity were positively correlated with the nematode structure index, maturity index, and genus diversity index. The trophic group diversity and size spectra slope of nematode communities were not significantly correlated with the carbon flux. The results indicate that mature and complex soil communities support high energy flux across soil food webs.
This review describes major advances in the use of functionalized molecular metal oxides (polyoxometalates, POMs) as water oxidation catalysts under electrochemical conditions. The fundamentals of ...POM-based water oxidation are described, together with a brief overview of general approaches to designing POM water oxidation catalysts. Next, the use of POMs for homogeneous, solution-phase water oxidation is described together with a summary of theoretical studies shedding light on the POM-WOC mechanism. This is followed by a discussion of heterogenization of POMs on electrically conductive substrates for technologically more relevant application studies. The stability of POM water oxidation catalysts is discussed, using select examples where detailed data is already available. The review finishes with an outlook on future perspectives and emerging themes in electrocatalytic polyoxometalate-based water oxidation research.
A facile and efficient method for the precise editing of large viral genomes is required for the selection of attenuated vaccine strains and the construction of gene therapy vectors. The type II ...prokaryotic CRISPR-Cas (clustered regularly interspaced short palindromic repeats (CRISPR)-associated (Cas)) RNA-guided nuclease system can be introduced into host cells during viral replication. The CRISPR-Cas9 system robustly stimulates targeted double-stranded breaks in the genomes of DNA viruses, where the non-homologous end joining (NHEJ) and homology-directed repair (HDR) pathways can be exploited to introduce site-specific indels or insert heterologous genes with high frequency. Furthermore, CRISPR-Cas9 can specifically inhibit the replication of the original virus, thereby significantly increasing the abundance of the recombinant virus among progeny virus. As a result, purified recombinant virus can be obtained with only a single round of selection. In this study, we used recombinant adenovirus and type I herpes simplex virus as examples to demonstrate that the CRISPR-Cas9 system is a valuable tool for editing the genomes of large DNA viruses.
Cultivation of legume plants is well known to improve soil N level and net primary productivity; besides, it may deliver other ecosystem benefits such as increasing soil carbon sequestration and soil ...food web complexity. However, little is known about whether legumes can improve the resistance of soils to ecosystem disturbances. In the present study, we compared the resistance of soils to an ecosystem disturbance (understory removal) in the presence or absence of a legume species (
) in mixed tree species plantations in southern China. Soil physico-chemical and biotic properties were employed to quantify the resistance of soils to understory removal. Our results showed that the resistance indices of soil water content, omnivorous-predacious nematode abundance and nematode channel index to understory removal were greater in the presence of legumes than those without legumes in wet season. The resistance indices of fungal to bacterial ratio, fungivorous nematode abundance and total arthropod abundance were greater in the presence of legume than those without legume species in dry season. Our results indicate that legumes may enhance the resistances of soil physico-chemical and biological properties to the ecosystem disturbance. Our findings could provide a better understanding of the myriad ways in which legumes can positively affect ecosystem functioning.
In south China, eucalyptus plantations typically consist of a single-species overstory (a eucalyptus monoculture) and a dense understory of a dominant fern species. In the current study, we assessed ...the effects of four treatments control (CK), understory removal (UR), tree removal (TR), and all-plant removal (PR) on the abundances of soil nematode genera, which can provide insight into the ecological functions of understory plants and trees. Soil nematodes were sampled six times (once before and five times after treatments were implemented) at 0–5 and 5–10 cm soil depths. The temporal dynamics of nematode genera were analyzed by the principle response curves (PRC) method. At 0–5 cm depth, the abundances of most nematode genera rapidly increased shortly after vegetation removal but then gradually decreased; the effects of UR were stronger than the effects of TR. The results might be explained by the pulsed input of plant debris to soil and its subsequent depletion. At 5–10 cm depth, the nematode communities were relatively unaffected by vegetation removal within the first 162 days, but the abundances of most genera sharply decreased on day 258 and then sharply increased on day 379 (the last sampling time). The results indicated that most nematode genera, even
r
-selected genera, were sensitive to vegetation removal in the upper soil layer and that understory vegetation can greatly affect soil nematode communities and presumably soil food webs. The nematode genera
Prismatolaimus
and
Diphtherophora
may be good indicators of the effects of vegetation removal. The results increase our understanding of the relationships between soil nematode genera and forest plant communities and of how soil biota is affected by forest management practices.
Chronic cerebral hypoperfusion (CCH) is the leading cause of cerebral small vessel disease (CSVD). CCH is strongly associated with blood-brain barrier (BBB) dysfunction and white matter lesions ...(WMLs) in CSVD. However, the effects of CCH on BBB integrity and components and the cellular and molecular mechanisms underlying the effects of BBB dysfunction remain elusive. Whether maintaining BBB integrity can reverse CCH-induced brain damage has also not been explored.
In this study, we established a rat model of CSVD via permanent bilateral common carotid artery occlusion (2VO) to mimic the chronic hypoperfusive state of CSVD. The progression of BBB dysfunction and components of the BBB were assessed using immunostaining, Western blotting, transmission electron microscopy (TEM) and RNA sequencing. We also observed the protective role of imatinib, a tyrosine kinase inhibitor, on BBB integrity and neuroprotective function following CCH. The data were analyzed using one-way or two-way ANOVA.
We noted transient yet severe breakdown of the BBB in the corpus callosum (CC) following CCH. The BBB was severely impaired as early as 1 day postoperation and most severely impaired 3 days postoperation. BBB breakdown preceded neuroinflammatory responses and the formation of WMLs. Moreover, pericyte loss was associated with BBB impairment, and the accumulation of serum protein was mediated by increased endothelial transcytosis in the CC. RNA sequencing also revealed increased transcytosis genes expression. BBB dysfunction led to brain damage through regulation of TGF-β/Smad2 signaling. Furthermore, imatinib treatment ameliorated serum protein leakage, oligodendrocyte progenitor cell (OPC) activation, endothelial transcytosis, microglial activation, and aberrant TGF-β/Smad2 signaling activation.
Our results indicate that reduced pericyte coverage leads to increased BBB permeability via endothelial transcytosis. Imatinib executes a protective role on the BBB integrity via inhibition of endothelial transcytosis. Maintenance of BBB integrity ameliorates brain damage through regulation of TGF-β/Smad2 signaling following CCH; therefore, reversal of BBB dysfunction may be a promising strategy for CSVD treatment.
Production of gamma-aminobutyric acid (GABA) was carried out in Erlenmeyer flasks by
Lactobacillus brevis
NCL912. Traditional methods were first adopted to select the key factors that impact the GABA ...production to preliminarily determine the suitable concentration ranges of the key factors. It was found that glucose, soya peptone, Tween-80 and MnSO
4
·4H
2
O were the key factors affecting GABA production. Then, response surface methodology was applied to analyze the optimum contents of the four key factors in the medium, and the production of GABA was predicted as 349.69 mM under the optimized conditions with this model. Afterward, the experiment was performed under the optimized conditions, and the yield of GABA reached 345.83 mM, which was 130% higher than the initial medium. The results showed that experimental yield and predicted values of GABA yield were in good agreement.
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