62 research outputs found
Diversity and assembly of active bacteria and their potential function along soil aggregates in a paddy field
No full textNumerous studies have found that soil microbiomes differ at the aggregate level indicating they provide spatially heterogeneous habitats for microbial communities to develop. However, an understanding of the assembly processes and the functional profile of microbes at the aggregate level remain largely rudimentary, particularly for those active members in soil aggregates. In this study, we investigated the diversity, co-occurrence network, assembly process and predictive functional profile of active bacteria in aggregates of different sizes using H
2
18O-based DNA stable isotope probing (SIP) and 16S rRNA gene sequencing. Most of the bacterial reads were active with 91 % of total reads incorporating labelled water during the incubation. The active microbial community belonged mostly of Proteobacteria and Actinobacteria, with a relative abundance of 55.32 % and 28.12 %, respectively. Assembly processes of the active bacteria were more stochastic than total bacteria, while the assembly processes of total bacteria were more influenced by deterministic processes. Furthermore, many functional profiles such as environmental information processing increased in active bacteria (19.39 %) compared to total bacteria (11.22 %). After incubation, the diversity and relative abundance of active bacteria of certain phyla increased, such as Proteobacteria (50.70 % to 59.95 %), Gemmatimonadetes (2.63 % to 4.11 %), and Bacteroidetes (1.50 % to 2.84 %). In small macroaggregates (SMA: 0.25-2 mm), the active bacterial community and its assembly processes differed from that of other soil aggregates (MA: microaggregates, <0.25 mm; LMA: large macroaggregates, 2-4 mm). For functional profiles, the relative abundance of important functions, such as amino acid metabolism, signal transduction and cell motility, increased with incubation days and/or in SMA compared to other aggregates. This study provides robust evidence that the community of active bacteria and its assembly processes in soil aggregates differed from total bacteria, and suggests the importance of dominant active bacteria (such as Proteobacteria) for the predicted functional profiles in the soil ecosystem.
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Dynamic Optimized Cleaner Production Strategies to Improve Water Environment and Economic Development in Leather Industrial Parks: A Case Study in Xinji, China
No full textThe leather industry has contributed significantly to economic development, but serious water environmental problems have arisen due to manufacturing processes in this industry. The leather industry must implement sustainable development by improving cleaner production capabilities under the Chinese ecological development background. The Xinji industrial park in China has the largest leather production base in which the leather industry is the leading industry that contributes nearly 50% of economic gains. This study investigated optimal cleaner production strategies for the leather industrial park by adopting an improved multi-objective simulation approach integrating the environmentally extended input–output and system dynamics models. Simulations were able to estimate the socio-economic and water environment development of the Xinji industrial park from 2015 to 2025. Adopting cleaner approaches, including production efficiency enhancing, sewage pre-treatment facility construction in leather companies, and reclaimed water recycling, simulation results indicated that, with steady economic growth (optimal 7.7% annual growth rate), it is possible to conserve 18% of the water resources, with an 80 % and 90% reduction for the chemical oxygen demand (COD), ammonia (NH3-N) water pollutant emission intensity, respectively. The cleaner development path and measures analyzed in this study are of great significance to promote the sustainable development of leather industrial parks
Atmospheric methane oxidation is affected by grassland type and grazing and negatively correlated to total soil respiration in arid and semiarid grasslands in Inner Mongolia
No full textMethane (CH
4) is an important trace greenhouse gas and atmospheric CH
4 uptake by high-affinity methanotrophs in grassland soil accounts for an important proportion of the terrestrial CH
4 sink. However, our understanding of the comprehensive effects of grassland type and grazing treatment on active soil methanotrophs and atmospheric CH
4 uptake is still under debate. This study investigates the impact of grazing on CH
4 oxidation rate and active atmospheric CH
4 oxidizing methanotroph communities in two arid and semiarid grassland ecosystems (meadow and desert) by detecting transcripts of methane monooxygenase (pmoA) genes. Atmospheric CH
4 oxidation rates differed according to grassland type and grazing treatment. The highest activity was found in desert grasslands with moderate grazing and the lowest activity in meadow grasslands with exclosures. The differences in activities were linked with changes in abundance, composition and co-occurrence network patterns of active methanotrophs and CO
2 production rate. Redundancy, correlation and random forest analyses indicated that pmoA transcripts, available phosphorus (AP), NO
3
−-N, and CO
2 production rate were the most important factors predicting active methanotroph community composition and atmospheric CH
4 oxidation activity in these grassland ecosystems. A glucose amendment incubation experiment showed that addition of glucose increased heterotrophic microbial respiration and inhibited atmospheric CH
4 oxidation. This study provides evidence that CO
2 production rate is an important factor associated with atmospheric CH
4 oxidation activity in arid and semiarid grassland ecosystems and suggests that interactions between methanotrophs and other heterotrophs influence methanotroph activity in grassland ecosystems.
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Origin and paleoenvironmental reconstruction of phosphorus–bearing sandstones of the Cambrian Xinji Formation, southwestern margin of Ordos Basin, China
No full textIncreasing exploration interest in oil and gas hosted by early Cambrian strata has focused research effort on early Cambrian sandstones. The origin of phosphorus and the paleoenvironment of phosphorus-bearing sandstones from the Xinji Formation are discussed in this paper. X-ray diffraction, optical microscopy, grain size analysis, total organic carbon (TOC), and the concentrations of major, trace, and rare earth elements (REEs) are analyzed in this work. The sandstones are mostly sublitharenite, with calcareous cement. The quartz content of the sandstone samples is 39.8–73.9%, with illite (7.9–27.6%) and calcite (4.5–29%). The mineral particles of sandstone samples are mainly well sorted with fine particle size, suggesting strong paleohydrodynamic force. The value of SiO2 is 37.69–78.19%, followed by Al2O3 (6.11–13.67%). Compared with UCC, the boron of sandstone samples is relatively enriched, while Sc, Sr, and Ba are relatively depleted. The ΣREE content is 124.46–323.99 ppm. Phosphorus is biogenic origin and enriched by upwelling current. The source of the Xinji Formation sandstone samples was mainly a mixture of sedimentary rock, granite and alkali basalt, with the provenance of terrestrial clastic materials. The sandstone deposited under oxic condition and warm and humid paleoclimate with saline to brackish feature in the passive continental margin. Phosphorus occurred in sandstones is sensitive to paleoclimate that can be used as an indicator to judged paleoclimate, and is more enriched in warm and humid weather.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author
Tetracycline treatment of type III prostatitis nanobacteria infection of 100 cases report
No full textAssessing non-inferiority with time-to-event data via the method of non-parametric covariance
No full text Non-parametric methods have been well recognised as useful tools for time-to-event (survival) data analysis because they provide valid statistical inference with few assumptions. Tangen and Koch have proposed the use of the method of non-parametric covariance for time-to-event data in a traditional superiority setting. In this article, we extended their method to assess non-inferiority of two treatments. To evaluate this non-parametric method versus the classical semi-parametric Cox proportional hazards regression model, simulations in terms of the Type 1 error rate and power were performed and compared. The results showed that the two methods were generally comparable regarding the Type 1 error rate when adjustment for the covariates correlated with the survival time was made. In the non-inferiority setting, the covariate-adjusted non-parametric analysis was shown to always increase power. However, this was not necessarily the case for the adjusted Cox model where results were inconsistent to those seen in the superiority setting. For illustration, an application of the proposed non-parametric method to a trial involving pemetrexed, a recently approved drug for first-line treatment of non-small cell lung cancer, is included. </jats:p
State self-earned income and welfare provision in China
No full textLocal governments in China in the 1990s relied increasingly on self-earned income, but little is known about the impact of this on the provision of public goods, especially in wealthy urban areas. This paper shows how departments charged with providing welfare and social services to the poor have been supplementing budgetary expenditures with other, self-earned, finance. Based on research in the city of Tianjin, it argues that although self-earned income can increase spending on welfare and social services, increasing reliance on such income, and variation in departmental capacities to generate it, exacerbate already inequitable welfare provision even within this wealthy city. It also creates conflicts of interest and problems for local government spending controls
Research on Blasting Technology in Large Cross Section Roadway Heading in Hard Rock at Depth
No full textAccording to the high hardness rock in Xinji 2nd Mine, the problem of low utilization of blasthole, an undesirable effect of blasting, and low circulating footage in the roadway construction has arisen. By analyzing the factors of the blasting effect in large section hard rock roadway excavation, it is to optimize the blasthole diameter, charge diameter, cutting modes, and other parameters of blasting. The results show that the improvement ensures good formation of large cross section roadway in hard rock while the heading speed and blasting efficiency are greatly enhanced by occupying the double wedge cut, increasing the number of ultra-deep middle cut, and expanding the diameter of the blasthole
Forward prediction for tunnel geology and classification of surrounding rock based on seismic wave velocity layered tomography
No full textExcavation under complex geological conditions requires effective and accurate geological forward-prospecting to detect the unfavorable geological structure and estimate the classification of surrounding rock in front of the tunnel face. In this work, a forward-prediction method for tunnel geology and classification of surrounding rock is developed based on seismic wave velocity layered tomography. In particular, for the problem of strong multi-solution of wave velocity inversion caused by few ray paths in the narrow space of the tunnel, a layered inversion based on regularization is proposed. By reducing the inversion area of each iteration step and applying straight-line interface assumption, the convergence and accuracy of wave velocity inversion are effectively improved. Furthermore, a surrounding rock classification network based on autoencoder is constructed. The mapping relationship between wave velocity and classification of surrounding rock is established with density, Poisson's ratio and elastic modulus as links. Two numerical examples with geological conditions similar to that in the field tunnel and a field case study in an urban subway tunnel verify the potential of the proposed method for practical application
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