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•Soil was a net CH4 sink in semi-arid regions; diffusive influx decreased with increasing soil depth.•CH4 transformation was greatest above 20 cm; CH4 consumption peaked at depth of ...10–20 cm.•N fertilizer promoted CH4 diffusion, and organic manure stimulated CH4 consumption.•Soil moisture inhibited CH4 diffusion and accelerated biochemical transformation.
To better understand the effects of fertilizer on soil methane (CH4) diffusion and consumption in semi- arid region, we investigated the subsurface CH4 concentrations at seven depths in the mineral soil and analysed the CH4 fluxes between soil horizons at the Changwu Agro-Ecological Station on China’s Loess Plateau. The results showed that dryland soil was a weak net CH4 sink. The CH4 concentration and diffusion decreased with increasing depth to a depth of 50 cm, and then remained low from 50 to 100 cm. Much of the soil CH4 diffusion and transformation occurred in the top 20 cm, but maximum CH4 production occurred at a depth of 7 cm, and maximum CH4 consumption occurred at a depth of 15 cm. Soil moisture could significantly inhibit gas diffusion and accelerate the biochemical transformation of CH4. In high-yield production system, the application of nitrogen fertilizer promoted CH4 diffusion, especially in the surface soil, but did not affect the transformation of CH4; thus, organic matter promoted CH4 diffusion and stimulated CH4 transformation, especially for CH4 consumption at a depth of 15 cm. Overall, the integrated application of manure and nitrogen fertilizer can not only have optimum yield, but also successfully play a very low risk of CH4 emission.
This study examines the impact of employment values on college students’ choice intention of slow employment, as well as the role of employment anxiety and social support in this process. A ...questionnaire survey is conducted among students from several universities in Haidian and Changping Districts of Beijing to test a theoretical model. It is found that the employment long-term income orientation and employment cost avoidance orientation significantly positively predicted the choice intention of slow employment, and employment anxiety plays a mediating role in this relationship. The short-term income orientation of employment significantly negatively affects the choice intention of slow employment. Social support moderates the impact of the long-term and short-term employment income orientation on employment anxiety and the mediation effect of employment anxiety. This study contributes to the literature on college students’ employment psychology and behavior, and it provides an approach for colleges and universities, society at large, families, and college students to reduce the choice intention of slow employment and achieve fuller employment.
Constant monitoring of driving conditions and observation of the surrounding area are essential for achieving reliable, high-quality autonomous driving. This requires more reliable sensors and ...actuators, as there is always the potential that sensors and actuators will fail under real-world conditions. The sensitive condition-monitoring methods of sensors and actuators should be used to improve the reliability of the sensors and actuators. They should be able to detect and isolate the abnormal situations of faulty sensors and actuators. In this paper, a developed model-based method for condition monitoring of the sensors and actuators in an electric vehicle is presented that can determine whether a sensor has a fault and further reconfigure the sensor signal, as well as detect the abnormal behavior of the actuators with the reconfigured sensor signals. Through the simulation data obtained by the vehicle model in complex road conditions, it is proved that the method is effective for the state detection of sensors and actuators.
Iron oxyhydroxides for heavy metal treatment have attracted wide attention. In this work, iron oxyhydroxides of isomeric FeOOH (GpI) and tunnel-structural schwertmannite/akaganéite (GpII) were ...selected to study chromium (Cr(III)) adsorption removal from acidic aqueous solutions by batch experiments, under various reaction time, adsorbate/adsorbent level, pH and anions. Adsorption processes well fitted to pseudo-second-order kinetics (R
= 0.992-0.999, except for 0.829 for Lep). Isotherm data could be fitted by Langmuir (R
= 0.901-0.985), Freundlich (R
= 0.884-0.985) and Temkin (R
= 0.845-0.961) models at pH 3.7. Langmuir maximum adsorption capacities (mg/g) were 10.4-18.8 (FeOOH, except for 3.08 for Gth2) in GpI, and 20.60/43.40 (Sch-Chem/Sch-Bio) and 12.80/24.70 (Aka-Chem/Aka-Bio) in GpII. Adsorption capacities would gradually increase as Cr(III) concentrations increased within 0-40 mg/L, and could be markedly affected by the SO
and H
PO
anions. There were stable adsorption capacities at about pH 3.7, and then increased at pH 3.7-4.1. The Fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS) results showed that adsorption mechanisms were electrostatic interaction and surface complexation. In addition, three optimal bio-/chem-schwertmannite and lepidocrocite adsorbents had good reusable properties and treating abilities of Cr(III)-polluted waters at pH 4.0. These results could provide a theoretical basis for the application of iron oxyhydroxides in removing Cr(III) from acid wastewaters.
The aim of present investigation was to elucidate the unrevealed beneficial role of diosgenin against an experimental model of TNBS (2,4,6-trinitrobenzenesufonic acid)-induced ulcerative colitis ...(UC). Colitis was induced in Sprague-Dawley rats by intrarectal administration of TNBS (in 50% ethanol). Then animals were treated with diosgenin (50, 100, and 200 mg/kg) for 14 days. Various biochemical, behavioral, molecular, and histological analysis was performed. Diosgenin significantly decreased (p < 0.05) TNBS-induced elevated colonic oxido-nitrosative damage, myeloperoxidase, hydroxyproline, mRNA expressions of proinflammatory cytokines (TNF-α, IL-1β, IL-6, and IFN-γ) and inflammatory markers (iNOs and COX-2) induced by TNBS. Western blot analysis relevated that TNBS-induced up-regulated protein expressions of NF-κB, IκBα, Bax, and Caspase-1 were markedly decreased (p < 0.05) by diosgenin treatment. It also markedly ameliorated the histological insults induced in the colon by TNBS. In conclusion, diosgenin exerts its colon-protective efficacy probably through the inhibition of NF-κB/IkB-α and Bax/Caspase-1 signaling pathways to experimental TNBS-induced ulcerative colitis.
ANOVA: Analysis of variance; 5-ASA: 5-aminosalicylic acid; Bax: Bcl-2-associated X protein; COX-2: Cyclooxygenase-2; DAI: Disease Activity Index; DMSO: Dimethyl sulfoxide; GAPDH: Glyceraldehyde 3-phosphate dehydrogenase; GSH: Glutathione; HP: Hydroxyproline; IAEC: International Animal Ethics Committee; IBD: Inflammatory Bowel Disease; IBS: Inflammatory Bowel Syndrome; IL's: Interleukin's; IFN-γ: Interferon-gamma; IκBα: nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor-alpha; iNOs: Inducible nitric oxide synthase; LTB4: Leukotriene B4; MDA: Malondialdehyde; MPO: Myeloperoxidase; NO: Nitric Oxide; NF-κB: Nuclear Factor-κB; ROS: Reactive Oxygen Species; SOD: Superoxide Dismutase; TNBS: Trinitrobenzene Sulfonic Acid; TNF-α: Tumor necrosis factor-α
Diosgenin inhibited NF-κB/IkB-α pathway to ameliorate TNBS-induced ulcerative colitis
Soil–water supply is the main factor limiting crop production across the Loess Plateau in China. A two-year field experiment was conducted to evaluate three possible water management practices – film ...mulching (FM), supplementary irrigation (SI) and rain-fed (RF, control) – in terms of resource capture and use efficiency in maize (
Zea mays L.) in this area. The cumulative intercepted photosynthetically active radiation (PAR
i), air thermal time (TT
air), soil thermal time (TT
soil) and evapotranspiration (ET) were monitored during both crop growing seasons, and the effects of the three treatments on the growth dynamics and grain yield (GY) of the maize crops were compared. The results showed that the FM treatment significantly accelerated development of the crop plants, and the SI treatment induced more rapid development in the vegetative stage than the RF treatment. Both FM and SI treatments markedly increased the shoot dry matter (DM) and GY (
p
<
0.05). The cumulative PAR
i, TT
air and TT
soil during the reproductive stage were all significantly increased by both the FM and SI treatments relative to the RF treatment (
p
<
0.05), correlating well with observed increases in DM and GY. Both the FM and SI treatments also resulted in significantly higher (
p
<
0.05) radiation use efficiency, and the FM treatment significantly increased the water use efficiency, by 23–25%, in both years (
p
<
0.05). The results show that the tested water management practices have significant effects on soil moisture and thermal conditions, and hence the rates of growth and development of maize, in fields on the Loess Plateau, China.
Although the goal of doubling food demand while simultaneously reducing agricultural environmental damage has become widely accepted, the dominant agricultural paradigm still considers high yields ...and reduced greenhouse gas (GHG) intensity to be in conflict with one another. Here, we achieved an increase in maize yield of 70% in on‐farm experiments by closing the yield gap and evaluated the trade‐off between grain yield, nitrogen (N) fertilizer use, and GHG emissions. Based on two groups of N application experiments in six locations for 16 on‐farm site‐years, an integrated soil‐crop system (HY) approach achieved 93% of the yield potential and averaged 14.8 Mg ha−1 maize grain yield at 15.5% moisture. This is 70% higher than current crop (CC) management. More importantly, the optimal N rate for the HY system was 250 kg N ha−1, which is only 38% more N fertilizer input than that applied in the CC system. Both the N2O emission intensity and GHG intensity increased exponentially as the N application rate increased, and the response curve for the CC system was always higher than that for the HY system. Although the N application rate increased by 38%, N2O emission intensity and the GHG intensity of the HY system were reduced by 12% and 19%, respectively. These on‐farm observations indicate that closing the yield gap alongside efficient N management should therefore be prominent among a portfolio of strategies to meet food demand while reducing GHG intensity at the same time.
Background Research findings indicate a putative indirect or latent association between phenylalanine (Phe) and Parkinson’s disease (PD). In this study, we aimed to analyze the causal relationship ...between Phe and PD by two sample Mendelian randomization (MR) analysis. Methods In this study, the PD-related dataset and Phe-related dataset were downloaded from Integrative Epidemiology U1nit (IEU) Open Genome-Wide Association Study (GWAS) database. Four algorithms (MR Egger, maximum likelihood, inverse variance weighting (IVW) and unweighted regression) were used to perform MR analysis. The sensitivity analysis (heterogeneity test, horizontal pleiotropy test and Leave-One-Out (LOO) analysis) was used to assess the reliability of MR analyses. Results In the forward MR analysis, Phe was a safety factor for PD ( p -value < 0.05 and odds ratios (OR) < 1). The results of reverse MR analysis showed that there was no causal relationship between PD and Phe ( p -value > 0.05). In addition, sensitivity analysis showed that MR analysis was reliable. Conclusion The results of this study revealed that Phe was a safety factor for PD, meaning that Phe reduced the risk of PD.
•Gravel and plastic film mulching improved soil moisture and temperature.•N2O emissions showed no difference between the mulched and non-mulched treatments.•Mulching treatments markedly reduced ...yield-scaled N2O emissions.•Plastic film mulching is more effective in reducing yield-scaled N2O emissions.•Rational N input is essential to reduce yield-scaled N2O emissions.
Plastic film and gravel mulching have long been used to improve crop production, but few studies have focused on the effects of these mulching practices on nitrous oxide (N2O) emissions. Understanding the response of N2O emission to soil surface mulching is beneficial for improving management practices. We performed two field experiments over two years in northwestern China to measure the annual N2O emissions using the static chamber technique: first, we compared the N2O emissions from non-mulched (BP), gravel-mulched (GM) and plastic film-mulched (FM) maize (Zea mays L.) fields that received an equivalent nitrogen (N) application rate; second, we monitored the N2O emissions from film-mulched maize fields that received different N application rates N applied at 0 (N0), 250 (N250) and 380 (N380) kgNha−1. Compared to the BP treatment, both the GM and FM treatments markedly improved the soil temperature and moisture, which significantly increased the maize yields and N uptake but did not increase the N2O emissions, most likely because the decreased soil mineral N content limited the N2O production. As a result, the yield-scaled N2O emissions were markedly reduced in the GM and FM treatments, and a greater reduction was observed in the FM treatment due to the higher grain yield. The N2O emissions persistently increased with an increasing N rate, but the grain yield peaked in the N250 treatment in which the N input was nearly equivalent to the maize N uptake. Consequently, low yield-scaled N2O emissions were obtained in the N250 treatment (125 and 155gN2O–NMg−1 grain in 2011–2012 and 2012–2013, respectively). Thus, we conclude that film mulching combined with an appropriate N input is a preferable management practice to improve the grain yield and to simultaneously minimize the direct N2O emission intensity in agriculture.
Mulching is widely used to increase crop yield in semiarid regions in northwestern China, but little is known about the effect of different mulching systems on the microbial properties of the soil, ...which play an important role in agroecosystemic functioning and nutrient cycling. Based on a 4-year spring maize (Zea mays L.) field experiment at Changwu Agricultural and Ecological Experimental Station, Shaanxi, we evaluated the responses of soil microbial activity and crop to various management systems. The treatments were NMC (no mulching with inorganic N fertilizer), GMC (gravel mulching with inorganic N fertilizer), FMC (plastic-film mulching with inorganic N fertilizer) and FMO (plastic-film mulching with inorganic N fertilizer and organic manure addition). The results showed that the FMO soil had the highest contents of microbial biomass carbon and nitrogen, dehydrogenase activity, microbial activity and Shannon diversity index. The relative use of carbohydrates and amino acids by microbes was highest in the FMO soil, whereas the relative use of polymers, phenolic compounds and amines was highest in the soil in the NMC soil. Compared with the NMC, an increased but no significant trend of biomass production and nitrogen accumulation was observed under the GMC treatment. The FMC and FMO led a greater increase in biomass production than GMC and NMC. Compare with the NMC treatment, FMC increased grain yield, maize biomass and nitrogen accumulation by 62.2, 62.9 and 86.2%, but no significant difference was found between the FMO and FMC treatments. Some soil biological properties, i.e. microbial biomass carbon, microbial biomass nitrogen, being sensitive to the mulching and organic fertilizer, were significant correlated with yield and nitrogen availability. Film mulching over gravel mulching can serve as an effective measure for crop production and nutrient cycling, and plus organic fertilization additions may thus have improvements in the biological quality of the soil and its sustainability in the rainfall-limited semiarid region.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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