Search

Understanding soil phosphorus (P) distribution and its key drivers is fundamental for sustainable P management. In this study, a 21-year fertilization experiment on black soil was carried out, setting up five fertilization treatments: unfertilized control (CK), nitrogen and potassium (NK), nitrogen, P and potassium (NPK), NPK plus straw (NPKS), and NPK plus manure (NPKM). The distribution and effecting factors of P pools within soil aggregates were investigated. Compared to CK, the NK and NPK treatments decreased calcium-associated P concentration in all aggregate fractions. Meanwhile, the NPK treatment significantly increased the organic P extracted from NaOH in unaggregated particles (<0.053 mm). This was mainly due to the reduction in soil pH. The NPKS and NPKM treatments increased almost all P forms in aggregates, especially Ca-P. For the NPKM treatment, inorganic P extracted from resin, NaHCO3, and NaOH increased as aggregate size increased. This was mainly because straw or manure addition promoted soil organic carbon (SOC) storage in aggregates, creating more sorption sites via association with amorphous metallic minerals, and, thus, facilitating P accumulation. In conclusion, decreasing soil pH by chemical fertilizers is an effective strategy for mobilizing soil P, whereas increasing SOC by straw or manure facilitates P accumulation. [ABSTRACT FROM AUTHOR]

Phosphorus (P) leaching from excessive P application is the primary pathway of P losses in agricultural soils. Different P fertilizer practices have mixed effects on P leaching. We conducted a meta-analysis of the relevant literature regarding the response of crop yields, soil-available P (AP), and total P (TP) leaching to reduced P input (RP) and an inorganic-organic combination fertilizer (NPKM) for different agricultural land-use types. Compared to conventional P application (CP), RP (10~90% reduction) did not reduce crop yields in vegetable fields (experiments were 1~4 years) but significantly reduced cereal yields by 4.57%. Compared to chemical fertilizer (NPK), NPKM significantly increased cereal yields by 12.73%. Compared to CP, RP significantly reduced AP at 0~60 cm in vegetable and cereal fields. The greatest reduction occurred at 20~40 cm in vegetable fields (40.29%) and 0~20 cm in cereal fields (34.45%). Compared to NPK, NPKM significantly increased the AP at 0~60 cm in vegetable fields, with the greatest increase (52.44%) at 20~40 cm. The AP at 0~40 cm in cereal fields significantly increased under the NPKM treatment, with the greatest increase at 0~20 cm (76.72%). Compared to CP, RP significantly decreased TP leaching by 16.02% and 31.50% in vegetable and cereal fields, respectively. Compared to NPK, NPKM significantly increased TP leaching in vegetable fields (30.43%); no significant difference in leaching occurred in cereal fields. P leaching, in response to RP, was influenced by the P amounts applied (34.49%); soil organic matter (14.49%); and TP (12.12%). P leaching in response to NPKM was influenced by multiple factors: rainfall (16.05%); soil organic matter (12.37%); soil bulk density (12.07%); TP (11.65%); pH (11.41%). NPKM was more beneficial for improving yields in cereal fields with low soil fertility and lower P-leaching risks. [ABSTRACT FROM AUTHOR]

In coastal areas, biofilms are often subject to disturbance by hydrodynamic forcing, bioturbation and human activities. These factors affect the influences biofilms have on the sediment. To reveal these effects, we studied laboratory‐incubated and field‐collected biotic sediments reworked by disturbances, and examined their stabilities and three‐dimensional microstructures using laboratory annular flume tests and a wet‐staining X‐ray microcomputed tomography method. We find that, when subject to disturbance, biofilms do not always establish mat‐like matrices that firmly armor the seabed and bio‐stabilize sediments, but instead, have a range of effects on sediment stability, including both bio‐stabilization and destabilization. Disturbance considerably alters microbial influences on sediment stability, but is not the only control. Given equal disturbance, whether or not sediments are bio‐stabilized largely depends on the state of bio‐sediment formation. At a relatively well‐developed state, an organic‐rich, adhesive polymer network tightly interconnects large amounts of sediment particles into aggregates, forms complex internal structures, and enhances sediment stability. By contrast, some bio‐sediment formations only ever reach a less well‐developed state, where scattered organic patches bind relatively few particles into aggregates and reduce sediment stability. Microbial growth likely has two opposing effects on sediment stability, by enhancing either weight/friction or lift/drag on aggregated particles. The former has the positive effect of enhancing sediment stability, whereas the latter can result in greater flow resistance and so have the opposite effect. A conceptual framework is put forward to characterize the different states of bio‐sediment formation and their distinct effects on sediment stability. [ABSTRACT FROM AUTHOR]

Aims To evaluate the protective effect of intestinal supplementation with Lacticaseibacillus casei CNRZ1874 on the inflammatory response induced by Mycoplasma pneumoniae in C57BL/6 J mice, and provide a potential strategy for alleviating M. pneumoniae pneumonia. Methods and results C57BL/6 J mice were gavaged with L. casei CNRZ1874 or PBS for 7 consecutive days, and then infected with M. pneumoniae on day 8. Treatment with L. casei CNRZ1874 significantly reduced M. pneumoniae loads in the lungs and alleviated the lung inflammation on day 3 and 10 after pathogen infection. Importantly, oral administration with L. casei CNRZ1874 promoted M1 alveolar macrophages activation as evidenced by increased expression of iNOS, TNF-α, and CXCL1, while inhibited M2 alveolar macrophages activation as the expression of Arg1 and Chi3l3 were significantly decreased. In consistent with the M1 alveolar macrophages activation and enhanced mycoplasma clearance, the level of TNF-α was increased while the level of IL-4 was decreased in lung tissue from the L. casei CNRZ1874 group compared with the control group. However, oral administration with L. casei CNRZ1874 may not influence adaptive immunity induced by M. pneumoniae as evaluated by M. pneumoniae specific antibodies and T cells responses in spleen. Conclusions Intestinal supplementation with L. casei CNRZ1874 can promote M1 alveolar macrophages activation, which contributes to the clearance of M. pneumoniae and attenuation of M.pneumoniae pneumonia. [ABSTRACT FROM AUTHOR]

Understanding the effects of a fertilization regime on the long-term accumulation and transformation of soil phosphorus (P) is essential for promoting the development of sustainable management of soil P. Based on a 29-year field experiment in Mollisol, the compositions and changes of P forms using a modified Hedley sequential extraction method, solution 31P-NMR and P K-edge XANES and soil properties were investigated under continuous mono maize with and without manure (NPKM and NPK). Results showed a stronger positive related coefficient between soil total P and labile P, and mid-labile P fraction was found in NPKM than in NPK treatment. It indicated NPKM could improve the availability of soil accumulated P and reduce its transformation to stable P. Accumulated inorganic P (Pi) was dominated by aluminum phosphate (Al-P) and monobasic calcium phosphate monohydrate (MCP) for NPK treatment, Al-P, MCP, and tricalcium phosphate for NPKM treatment with XANES analysis, which contributed to the P availability in Mollisol. Moreover, the proportion of IHP with XANES and ratio of orthophosphate diesters to monoesters in NPK compared to NPKM indicated the higher Po lability with NPK treatment. Pi, especially NaHCO3-Pi and NaOH-Pi, were the potential sources of resin-Pi. Soil organic matter (SOM), organic-bound iron, and alumina oxide (Fep + Alp) showed significant influence on the transformation of P forms. Our research suggested that due to the rise in SOM and Fep + Alp, the fertilization regime significantly increased most highly active soil P fractions, especially in NPKM treatment. This work gives new insight into sustainable P management, which benefits the reduction in soil P accumulation. [ABSTRACT FROM AUTHOR]

Five coal samples obtained from Chinese coal-producing areas were oxidized by hydrogen peroxide (H2O2), and humic acids (HAs) were derived from original coal and its oxidizition samples. HAs were characterized by physical and chemical methods, between which was also comparison. Yield, ash, aromaticity, molecular weight and functional group of HAs showed variance between original coals. While, yield, molecular weight, and the quantity of oxygen-containing groups of HAs increased more from coals oxidized with H2O2. However, the increase of oxygen-containing functional groups depended on original coals. For Yimin lignite, the oxidation of H2O2 could obviously improve the carboxyl group content of HAs, thus promoting the adsorption of nitrogen. This study demonstrated that oxidation of coal by using H2O2 was one pretreatment way to obtain and modify HAs which could be used as prerequisite and functional material in agricultural field. [ABSTRACT FROM AUTHOR]

This paper proposes a parallel computation model for the self-organizing map (SOM) neural network applied to Euclidean traveling salesman problems (TSP). This model is intended for implementation on the graphics processing unit (GPU) platform. The Euclidean plane is partitioned into an appropriate number of cellular units, called cells, and each cell is responsible of a certain part of the data and network. Compared to existing GPU implementations of optimization metaheuristics, which are often based on data duplication or mixed sequential/parallel solving, the advantage of the proposed model is that it is decentralized and based on data decomposition. Designed for handling large-scale problems in a massively parallel way, the required computing resources grow linearly along the problem size. Experiments are conducted on 52 publicly available Euclidean TSP instances with up to 85,900 cities for the largest TSPLIB instance and 71,009 cities for the largest National TSP instance. Experimental results show that our GPU implementations of the proposed model run significantly faster than the currently best-performing neural network approaches, to obtain results of similar quality. [ABSTRACT FROM AUTHOR]

Current accurate stereo matching algorithms employ some key techniques that are not suitable for parallel GPU architecture. It will be tricky and cumbersome to directly take these techniques into GPU applications. Trying to tackle this difficulty, we design two GPU-based stereo matching algorithms, one using a local fixed aggregation window whose size is configurable, and the other using an adaptive aggregation window which only includes necessary pixels. We use the winner-takes-all (WTA) principle for optimization and a plain voting refinement for post-processing; both do not need complex data structures. We aim to implement on GPU platforms fast stereo matching algorithms that produce results with same-level quality as other WTA local dense methods that use window-based cost aggregation. In our GPU-based implementation of the fixed window partially demosaiced CFA stereo matching application, accelerations up to 20 times are obtained for large size images. In our GPU-based implementation of the adaptive window color stereo matching application, experiment results show that it can handle four pairs of standard images from Middlebury database within roughly 100 ms. [ABSTRACT FROM AUTHOR]

Plant NAPDH oxidase (NOX) gene family members are critical producers of ROS and play crucial roles in plant signaling, development, and stress responses. Opisthopappus taihangensis is a pivotal wild genetic resource in Asteraceae. To date, little knowledge exists about the functions of NOXs in O. taihangensis. In this study, seven typical NOXs and seven ferric reduction oxidases (FROs) were identified in O. taihangensis. Dispersed duplication might play a critical role in the expansion of the NOX/FRO gene family in O. taihangensis, and most of the NOX/FRO homologous pairs have undergone purifying selection. Although the results of the collinearity analysis show that these genes were relatively conserved, the gain and loss of members in this gene family occurred frequently during the evolution of Asteraceae. Phylogenetic analysis indicated that the FROs are relatively ancient, and the earliest diverged branch was revealed by the maximum likelihood (ML) tree. The Asteraceae NOXs were divided into six subgroups according to their relationship with Arabidopsis and rice members. The transcriptome profile unveiled tissue-specific expression patterns and complex response modes under drought and salt stresses. OtNOX6 and OtNOX7 could be recognized as important candidates to respond to drought and salt stress. Our results provide clues and references for further in-depth exploration of NOX/FRO function in O. taihangensis and other horticulture plants. [ABSTRACT FROM AUTHOR]

[Display omitted] • Soil erosion and mechanical compaction significantly altered the concentration and quality of DOC in sloping land, leading to changes in CO 2 emissions and a heightened Q 10 response. • Heavy compaction increased CO 2 emissions in the erosional site but decreased them in the depositional site. • Warming may amplify the risk of CO 2 emissions in sloping land, particularly in the context of global climate warming. • Soil compaction and erosion interactions have implications for the carbon cycle in terrestrial ecosystems. Soil erosion and mechanical compaction on sloping arable land can significantly influence soil carbon turnover. However, the interactive effects of soil erosion and mechanical compaction on soil carbon dioxide (CO 2) emissions, temperature sensitivity (Q 10), and dissolved organic carbon (DOC) in sloping arable soils remain uncertain. This study aimed to explore the effects of three mechanical compaction levels: heavy compaction (HP), light compaction (LP), and no compaction (NP), on DOC characteristics, CO 2 emissions, and Q 10 in both erosional and depositional sites. Two locally widely used tractors, a 220 horsepower (high pressure, HP) and a 25 horsepower (low pressure, LP), were used to simulate different levels of soil compaction by traveling back and forth through the ridge and furrow three times. We found that the DOC concentration in the depositional site was 15.8 % higher than that in the erosional site without compaction; however, after HP, the DOC concentration in the depositional site was 82.6 % higher than that in the erosional site. HP reduced DOC concentration in the erosional site by 26.1 %, while DOC concentration in the depositional site increased by 16.5 %. LP reduced DOC concentration in the erosional site but did not result in significant changes in the depositional site. Notably, the effect of HP on C mineralization varied with erosional and depositional sites. In the erosional site, HP increased CO 2 emissions by 29.4 % and 36.7 % at 15 °C and 25 °C, respectively, compared with NP. Conversely, in the depositional site, HP decreased CO 2 emissions by 27.8 % and 31.3 % compared with NP at the same temperatures, respectively. LP did not have a significant effect on CO 2 emissions at the erosional and depositional sites. Furthermore, soil CO 2 emissions from sloping arable land were primarily regulated by soil DOC content and DOC properties such as hydrophobicity and molecular weight. Intensive mechanical compaction significantly altered the concentration and quality of DOC in sloping land, thereby leading to notable changes in CO 2 emissions and a heightened Q 10 response. These findings emphasize the intricate nature of soil compaction and erosion interactions, and their potential implications for the carbon cycle in terrestrial ecosystems. [ABSTRACT FROM AUTHOR]

In recent years, igneous reservoirs have been the focus of natural gas exploration and development, which can help solve the energy demand, and in addition, when oil and gas reservoirs are depleted, volcanic reservoirs provide good storage space, transport channels and storage capacity, and this is very beneficial for CO2 storage. For reservoir prediction and CO2 storage monitoring, fluid discrimination techniques are very important. For igneous rock, the lithology and mineral composition, porosity, and pore structural characteristics are known to all affect the distribution patterns and saturation of fluid. The presence of high resistivity water layers and low resistivity gas layers will affect the accuracy of fluid discrimination using resistivity data. In this study, based on core experiments, the G-B-P (Gassmann-Brie-Patchy)equation was adopted to describe the relationships between the acoustic velocity and fluid saturation values. Then, finite element acoustic logging numerical simulations of wells were carried out to obtain the array logging full waveforms of the different lithology, porosity, and saturation. Finally, the ICEEMDAN(Improved Complete Ensemble Empirical Mode Decomposition with Adaptive Noise) mode decomposition method and SPWVD were used to analyze the time-frequency characteristics of the simulated waveforms, and a fluid discrimination chart of gas layer was established. The results of the synthetic and field data experiments using the proposed method demonstrated that it was a good approach for fluid discrimination processes in igneous gas reservoirs. • ICEEMDAN-SPWVD time-frequency analysis. • Full waveforms simulation based on Gassmann-Brie-Patchy equation. • A Fluid Discrimination Method based on array acoustic logging. [ABSTRACT FROM AUTHOR]

ABSTRACT Chen, X.D.; Wang, J.; Zhang C.K.; Yu S.B.; Zhou J.J.; Zhang N.Y., and Feng, Q., 2018. Biological mediation of sediment erosion: Can we account for tidal effects?. In: Shim, J.-S.; Chun, I., and Lim, H.S. (eds.), Proceedings from the International Coastal Symposium (ICS) 2018 (Busan, Republic of Korea). Journal of Coastal Research, Special Issue No. 85, pp. 421–425. Coconut Creek (Florida), ISSN 0749-0208. Sedimentology and geomorphology have no longer been seen as fields where only physical and chemical processes dominate. Changes in shear stress due to tidal effects may lead to repeated cycles of biofilm growth, erosion, and regrowth that produce conditions different from the steady-state ones often examined in the laboratory. Therefore, repeated cycles of laboratory-controlled experiments were conducted. Algal biofilm was initially developed on the sediment bed under low shear stress (0.06 Pa). After the biofilm reached a quasi-steady state (12 days of cultivation), the bio-bed was eroded with stepwise increment of shear forces, and then allowed to re-grow for only 5 days before being eroded again. The first cycle aimed to test whether the biological cohesion could recover during a relatively short calm period. After then, it was followed by six consecutive times of repeated procedure of 5-days-growth, erosion and regrowth (two under limited nutrients and four under rich nutrients), to investigate the responses of bio-beds under frequent disturbances and different nutrients abundance. The data showed that for the first cycle, the strength of the bio-bed surprisingly restored to the similar level of the bio-bed incubated for 12 days, within a relatively short recovery period of only 5 days after the disturbance. However, with nutrients limitation, the anti-erodibility declined dramatically that after two cycles, the bed stability rapidly reverted back to the non-cohesive condition. After four cycles under high nutrients, the biological cohesion rebuilt gradually but was hard to reach to the original strength. Different from the traditional assumption, our results indicate that in intertidal zones frequent disturbances cannot entirely inhibit the establishment of bio-sediment, and the biological mediation in sediment stability still occurs without nutrients limitation. [ABSTRACT FROM AUTHOR]

Chen, X.D.; Wang, J.; Zhang C.K.; Yu S.B.; Zhou J.J.; Zhang N.Y., and Feng, Q., 2018. Biological mediation of sediment erosion: Can we account for tidal effects?. In: Shim, J.-S.; Chun, I., and Lim, H.S. (eds.), Proceedings from the International Coastal Symposium (ICS) 2018 (Busan, Republic of Korea). Journal of Coastal Research, Special Issue No. 85, pp. 421–425. Coconut Creek (Florida), ISSN 0749-0208. Sedimentology and geomorphology have no longer been seen as fields where only physical and chemical processes dominate. Changes in shear stress due to tidal effects may lead to repeated cycles of biofilm growth, erosion, and regrowth that produce conditions different from the steady-state ones often examined in the laboratory. Therefore, repeated cycles of laboratory-controlled experiments were conducted. Algal biofilm was initially developed on the sediment bed under low shear stress (0.06 Pa). After the biofilm reached a quasi-steady state (12 days of cultivation), the bio-bed was eroded with stepwise increment of shear forces, and then allowed to re-grow for only 5 days before being eroded again. The first cycle aimed to test whether the biological cohesion could recover during a relatively short calm period. After then, it was followed by six consecutive times of repeated procedure of 5-days-growth, erosion and regrowth (two under limited nutrients and four under rich nutrients), to investigate the responses of bio-beds under frequent disturbances and different nutrients abundance. The data showed that for the first cycle, the strength of the bio-bed surprisingly restored to the similar level of the bio-bed incubated for 12 days, within a relatively short recovery period of only 5 days after the disturbance. However, with nutrients limitation, the anti-erodibility declined dramatically that after two cycles, the bed stability rapidly reverted back to the non-cohesive condition. After four cycles under high nutrients, the biological cohesion rebuilt gradually but was hard to reach to the original strength. Different from the traditional assumption, our results indicate that in intertidal zones frequent disturbances cannot entirely inhibit the establishment of bio-sediment, and the biological mediation in sediment stability still occurs without nutrients limitation. [ABSTRACT FROM AUTHOR]

To accurately evaluate altered volcanic reservoirs in the Songliao Basin of China and study the effect of alteration on pore structure, this paper established a methodology for log evaluation based on conventional log data. The volcanic reservoir in the Songliao Basin, China is variable in lithology, complex in pore structure and widespread in alteration phenomena. Because of these problems, the conventional charting method is not good at lithological identification, and the reservoir interpretation conclusions based on interpretation of the conventional logging method are not consistent with the actual logging data, making it difficult to carry out accurate logging evaluation. To solve such problems, this study adopted the particle swarm optimization-support vector machine (PSO-SVM) for carrying out lithological identification. Then, alteration factors were established to evaluate the alteration degree of volcanic reservoirs and obtain the altered clay content by fitting to correct the effect of alteration. Designing the volume model that considered altered clay and selecting the Simandoux model that could correct the influence of clay to calculate relevant petrophysical parameters such as porosity and water saturation, thus formed a methodology of logging evaluation suitable for the altered volcanic reservoir in the study area. At the same time, the study found that for different volcanic rocks, the effects of alteration on pore structure are different. An analysis, in combination with alteration factors and T 2 NMR spectra, showed that for the volcanic reservoir of nonsevere alteration, the higher the alteration degree, the greater the total porosity and the void porosity. However, with increasing alteration degree, the effective porosity of andesite was higher, while that of tuff worsened. The findings may provide a new idea for the analysis of the pore structure of altered volcanic reservoirs. • This paper presents a workflow for logging evaluation of altered volcanic reservoirs. • Proposes a method to evaluate the degree of alteration. • Analyzes the influence of alteration on the pore structure of volcanic reservoir. [ABSTRACT FROM AUTHOR]