Moringa oleifera
(moringa) is an important fodder tree species. Although several researches study the effects of fertilization on moringa growth, the response of non-structural carbohydrate (NSC) to ...nitrogen (N) and phosphorus (P) fertilization in moringa seedlings is poorly understood. Here, we employed a pot experiment to investigate the effects of N and P fertilization on NSC dynamics in moringa seedlings in southern China. The results showed that the moringa root NSCs were 427 mg g
−1
in the control treatment (over 50% of the total NSCs, 739.8 mg g
−1
), while the leaf NSCs only stored about 10% of NSCs in the individual tree. Compared to the control treatment, the NSCs in leaf, stem, and root of moringa seedlings were greatly reduced by N and P fertilization, which could be explained by the dilution effects of increased biomass following fertilization. However, the magnitude of NSC change with fertilization varied with tissue and N & P application levels. Our results suggest that there is a trade-off between structural carbohydrates (SCs) and NSCs among different organs in morniga seedlings. As moringa seedlings may have specific nutrient acquiring strategies that differs from their adult tree, long-term and large-scale researches should focus on the effects and underlying mechanisms of fertilization on the trade-off between SC and NSC in seedling and the adult tree of moringa in future.
Heat waves (HWs) can have disastrous impacts on human activities and natural systems, and are one of the current foci of scientific research, particularly in the context of global warming. However, ...there is no standard definition of a HW, which makes assessment of temporal trends a challenge. In this study, based on daily mean, maximum and minimum temperature, and relative humidity datasets from China Meteorological Administration, the patterns, trends and variations of HW in China during 1961–2014 are investigated. Sixteen previously published HW indices (HIs) are calculated, which are divided into two types using relative and absolute threshold temperatures, respectively. During 1961–2014, both relative and absolute threshold HIs show the highest number of HW in Jianghua and South China, geographically consistent with the climate characteristics of China. The majority of HIs shows negative/positive trends of HW days before/after 1990 over the whole of China, but especially in Jianghua and South China, which reflects rapid warming since 1990. There are significant correlations among different HIs in the same type (both absolute and relative), but correlations are weak between relative and absolute threshold HIs. Because relative and absolute HIs show contrasting trends, the choice of HI is therefore critical for future analysis
At present, most of the pitch control methods are based on PI controller, the pitch control system has poor disturbance resistance, and the research of variable parameter feedforward based on Light ...detection and ranging (LIDAR) and the Linear Active Disturbance Rejection controller (LADRC) composite control is rarely studied to reduce the blade root load, so this paper conceives a hybrid intelligent and adaptive pitch control approach to reduce a wind turbine generator speed fluctuation and its blade root load. Specifically, we combine the Radial Basis Neural Network and Finite Impulse Response filter (RBFNNFIR) based on LIDAR wind measurement. We then use a variable bandwidth of LADRC controller. Overall the approach enables and facilitates self-adaption and self-adjustment. We use Matlab s-function to call the multi-freedom mathematical wind turbine model based on FAST code, the composite intelligent control algorithm is established in Simulink. Initial results from the statistical analysis of the experiments under different turbulent wind conditions shows that the hybrid intelligent pitch control approach can reduce the generator speed fluctuation by about 40.8%, and the blade root max value of load moment by about 13.1%, compared with the baseline values of the traditional variable gain PI control algorithm.
•A novel hybrid pitch control algorithm is conceived, developed and evaluated.•The LIDAR-based feedforward control allows a pitch actuator to act in advance.•RBFNNFIR can realize self-adaption/adjustment of the feedforward controller.•The new variable LADRC demonstrates strong anti-interference and robustness.•The hybrid algorithm reduces generator speed fluctuation by 40.8%, blade root load by 13.1%.
Arbuscular mycorrhizal fungi (AMF) are present in paddy fields, where they suffer from periodic soil flooding and sometimes shading stress, but their interaction with rice plants in these ...environments is not yet fully explained. Based on two greenhouse experiments, we examined rice-growth response to AMF under different flooding and/or shading regimes to survey the regulatory effects of flooding on the mycorrhizal responses of rice plants under different light conditions. AMF had positive or neutral effects on the growth and yields of both tested rice varieties under non-flooding conditions but suppressed them under all flooding and/or shading regimes, emphasizing the high importance of flooding and shading conditions in determining the mycorrhizal effects. Further analyses indicated that flooding and shading both reduced the AMF colonization and extraradical hyphal density (EHD), implying a possible reduction of carbon investment from rice to AMF. The expression profiles of mycorrhizal P pathway marker genes (
GintPT
and
OsPT11
) suggested the P delivery from AMF to rice roots under all flooding and shading conditions. Nevertheless, flooding and shading both decreased the mycorrhizal P benefit of rice plants, as indicated by the significant decrease of mycorrhizal P responses (MPRs), contributing to the negative mycorrhizal effects on rice production. The expression profiles of rice defense marker genes
OsPR1
and
OsPBZ1
suggested that regardless of mycorrhizal growth responses (MGRs), AMF colonization triggered the basal defense response, especially under shading conditions, implying the multifaceted functions of AMF symbiosis and their effects on rice performance. In conclusion, this study found that flooding and shading both modulated the outcome of AMF symbiosis for rice plants, partially by influencing the mycorrhizal P benefit. This finding has important implications for AMF application in rice production.
Arbuscular mycorrhizal fungi (AMF) are commonly present in wetlands, but their functional role there is not well understood. We have quantified the carbon (C) allocation from rice to AMF under ...different flooding regimes, using stable isotope labeling (13CO2), and assessed the potential phosphorus (P) delivery from AMF to rice by profiling the expression of plant and fungal P transporter genes. The results showed that the plant-assimilated C was allocated to AMF under all flooding regimes, as evidenced by the significant enrichment of 13C in the AMF signature fatty acids. The plant C allocation to AMF declined at increased flooding intensity, and was strikingly greater at the growth stage when the rice plants had a higher nutrient requirement. The gene expression profiles and rice P levels strongly indicated that a considerable amount of P was transported to plants via the mycorrhizal pathway under wetland conditions, although AMF colonization did not improve rice growth. This work provides the first solid evidence of C‒P exchange in AM symbiosis under flooded conditions, although it is reduced compared to non-flooded conditions. Nonetheless, this means that AMF may have an important function in wetlands, which opens new perspectives on the application of symbiotic AMF in wetlands.
•Plant-assimilated C was allocated to AMF under all flooding regimes.•Plant C allocation to AMF declined at increased flooding intensity.•Plant C allocation to AMF was greater when rice had a higher nutrient requirement.•We found support for mycorrhizal P transport to rice plants in wetland conditions.•This is the first evidence of C–P exchange in AM symbiosis in flooded soil.
Ammonia (NH3) is a major pollutant in livestock houses and atmospheric environment. It has been demonstrated that NH3 can cause a series of damage to animals and human. However, toxicity evaluation ...of NH3 on farm animals was rarely reported, especially in the intestinal microflora. Therefore, in this study, twenty-four 125-day-old fattening pigs were randomly divided into 4 groups: control group, NH3 group (88.2 mg m−3 < NH3 concentration < 90.4 mg m−3), Se group (Se content: 0.5 mg kg−1), and NH3 + Se group (88.2 mg m−3 < NH3 concentration < 90.4 mg m−3, Se content: 0.5 mg kg−1), and the effects of NH3 and L-Selenomethionine on the microbiota composition in the jejunum and the levels of inflammatory markers in feces of fattening pigs were examined by 16S rDNA and ELISA, respectively. Our results showed that the content of Matrix metalloproteinase-9 (MMP-9), Myeloperoxidase (MPO), Lactoferrin (LTF) and Calprotectin in the ammonia group (A group) were significantly elevated compared to the control group, and the content of MMP-9, MPO, LTF and Calprotectin in the A + Se group were significantly reduced. A significant difference in microbiota composition in the phylum, class, family and genus levels was found in the A group and the NH3 + Se group. There was a negative correlation between Streptococcus and Calprotectin. Our results indicated that excessive NH3 inhalation could cause changes in inflammatory markers and beta diversity of intestinal microflora in fattening pigs. We found there was a positive correlation between MPO and Pseudomonas. In addition, we first proposed that L-Selenomethionine could improve the imbalance of microbial flora and the inflammatory injury caused by NH3. Changes in intestinal microflora and inflammatory markers can be used as important indicators to evaluate NH3 toxicity, and studying changes in intestinal microflora is also an important mechanism to reveal NH3 toxicity.
Display omitted
•Ammonia is a typical pollutant in atmospheric environment and livestock production.•Excessive ammonia exposure can cause the changes in inflammatory markers.•Excessive ammonia exposure can cause the imbalance of intestinal microflora.•L-selenomethionine can improve the imbalance of intestinal flora caused by ammonia.•Intestinal flora is involved in the toxic mechanism of ammonia.
Ammonia (NH3) is a major gaseous pollutant in livestock production and has adverse effects on production, health and welfare of animals. The liver is one of the target organs of NH3, and excessive ...NH3 inhalation can induce liver damage. However, the toxicity assessment of NH3 on pig liver and its mechanism have not been reported yet. Recently, transcriptome analysis has become a major method to study the toxic mechanism of pollutants in environmental toxicology. Therefore, in the present study, we examined the effects of excessive NH3 inhalation on the liver of fattening pig through chemical analysis, ELISA, transcriptome analysis and real-time quantitative PCR (qRT-PCR). Our results showed that the transcriptome analysis database of fattening pig liver under excessive NH3 exposure, and 449 differentially expressed genes (DEGs) (including 181 up-regulated DEGs and 168 down-regulated DEGs) were found. Some genes associated with the 3 Gene Ontology (GO) terms (liver function, immune, antioxidant defense) were validated by quantitative real-time PCR. In addition, the activities of GPT and GOT in NH3 group were significantly increased by 63.5% and 37.4% (P < 0.05), respectively. Our results indicated that NH3 exposure could cause changes in transcriptional profiles and liver function, and induce liver damage in fattening pigs through oxidative stress and immune dysfunction. Our study results not only provide a new perspective for the toxicity assessment of NH3, but also enrich the toxicological mechanism of NH3.
Display omitted
•Ammonia exposure caused changes in transcriptional profiles and liver function.•Ammonia exposure induced liver damage through oxidative stress and immune dysfunction.•181 up-regulated DEGs and 168 down-regulated DEGs were screened in the ammonia group.•GO terms concentrated in biological processes, cellular component and molecular function.
Ammonia is an acknowledged environment pollutant in atmosphere with irritating smell. Previous studies have shown that excessive ammonia has toxic effects on farm animals and humans. However, the ...detail toxicity mechanism of ammonia to pigs is still unknown so far. In order to clarify the mechanism of ammonia toxicity, we established a porcine exogenous ammonia poisoning model and assessed the effects of ammonia on the gut-brain axis by transcriptome sequencing, histological observation and chemical analysis. Our results showed that after 30 d of ammonia exposure, 578 differentially expressed genes (DEGs) and 407 DEGs were obtained in the hypothalamus and jejunum, respectively. These DEGs were enriched into Gene Ontology terms associated with inflammation, oxidative metabolism, apoptosis, and the highly expressed genes among these DEGs were verified by real-time quantitative PCR. The content of glutathione and the activities of glutathione peroxidase and superoxide dismutase were significantly decreased, while malondialdehyde content was increased after ammonia exposure. Corticotropin releasing factor, substance P, 5-hydroxytryptamine and ghrelin contents in serum elevated significantly. Furthermore, pathologic observation in the ammonia group revealed infiltration of lymphocytes in the hypothalamus and significant decrease of jejunal epithelial cells. Our results indicated that ammonia exposure mediated changes in transcriptional profiles, pathological damage, oxidative stress and brain-gut peptide of the pig jejunum and hypothalamus, and induced the imbalance of the brain-gut axis through the “oxidative stress-inflammation-apoptosis” interaction network. Our study not only provides a new perspective for the toxicity assessment of ammonia, but also enriches the toxicology mechanism of ammonia.
Display omitted
•Ammonia caused the change of transcriptional profiling in pig gut-brain axis.•Ammonia induced oxidative stress, inflammation and apoptosis in gut-brain axis.•Ammonia exposure caused changes in serum brain-gut peptide.•Ammonia exposure resulted in imbalance of the gut-brain axis.
SUMMARY
Determining a detailed 3-D velocity model with high resolution for the sedimentary layer in the Sichuan Basin is potentially beneficial both to the industrial oil/gas exploration and ...earthquake hazards’ mitigation. In this study, we apply the ambient noise tomography method to construct a 3-D S-wave velocity model. This model focuses on the sedimentary layer of the Sichuan Basin, with a 0.3° × 0.3° grid precision. Dispersion curves of both group and phase velocities of Rayleigh wave at 4 to 40 s periods are utilized, which are extracted from 87 broad-band stations in the Sichuan Basin and the surrounding areas. The 3-D model reveals a thick sedimentary layer of the Sichuan Basin with S-wave velocity ranging from ∼2.0 to 3.4 km s−1. The sediment thickness in the margins of the Sichuan Basin is generally greater than the typical values of 6–10 km in the central areas due to surrounding orogenic activities, with a maximum depth of ∼13 km in the northwestern margin. Moreover, a prominent low S-wave velocity anomaly in the margins may be caused by the sediment accumulations from large-scale landslides and pronounced denudation of the surrounding orogenic belts. Major geologic units in the sedimentary layer are delineated in this study. The S-wave velocity values within each geologic unit and their bottom interfaces are obtained. Based on our model, we calculate synthetic ground motions for the 2013 Lushan earthquake and obtain the distribution of the peak ground acceleration from the earthquake epicentre to the western Sichuan Basin. The result clearly illustrates the basin amplification effect on the seismic waves.
This study presents new seismic data and interpretations for the deep structure in the southwest Cathaysia block comprised of Yunkai, Yuegui and Yuezhong blocks. A dense seismic array consisting of ...112 short-period, three-component seismic stations was deployed to investigate the geodynamic mechanism of the nappe tectonic zone and gold mineralization with 2.5 km spacing across the Luoding-Yunfu region. Based on this dataset, we are able to image the high-resolution crustal structures of the southwest Cathaysia block using the P-wave receiver function method. Our imaging results reveal distinct structural features beneath the study region, including marked lateral variations of Moho discontinuities. Beneath the Luoding-Yunfu nappe tectonic zone, the Moho uplift indicates that its formation is related to deep melt mantle (e.g., Asthenospheric mantle OIB). Moho features depicted by the Ps image are different from those by the PpPs phase along this tectonic zone, which could be ascribed to the local complex structures as illustrated in the forward analysis for different Moho structures. Such a uplift is also observed from the H-κ stacking results and a low average Vp/Vs ratio (~1.65) is found in this region, which could be attributed to its location within a tectonic strain zone. Based on the analysis and comparisons with previous studies, we infer that the crustal uplift in the Luodin-Yunfu area could be a typical scenario of the ore-controlling structure. This study also suggests that upwelling channels of deep melt mantle in the southwest Cathaysia block could facilitate the progress of migration, enrichment and precipitation of gold mineralization.
•We obtain the high-resolution crustal structure in the southwest Cathaysia block with a dense seismic array.•Beneath the Luoding-Yunfu nappe tectonic zone, the Moho uplift indicates that its formation is related to deep melt mantle.•Upwelling channels of deep melt mantle facilitate migration, enrichment and precipitation of gold mineralization.
PDF
