Comparative miRNA expression profile analysis of porcine ovarian follicles: new insights into the initiation mechanism of follicular atresia

Follicular atresia occurs in every stage of ovarian development, which is relevant to female fertility. In the past decade, increasing studies have confirmed that miRNAs, a class of short non-coding RNAs, play an important role in follicular atresia by post-transcription regulation of their target genes. However, the function of miRNAs on follicular atresia initiation is unknown. In the present study, high-throughput small RNA sequencing was performed to analyze differential miRNA expression profiles between healthy (HF) follicles and early atretic (EAF) follicles. A total of 237 conserved miRNA were detected, and the miR-143 is the highest expressed in follicles. Meanwhile, we also found wide sequence variations (isomiRs) in porcine ovarian miRNA, including in 5′un-translation region, core seed sequences and 3′untranslation region. Furthermore, we identified 22 differentially expressed miRNAs in EAF groups compared to HF group, of which 3 miRNAs were upregulated, as well as 19 miRNAs were downregulated, and then the RT-PCR was performed to validate these profiles. The target genes of these differentially expressed miRNAs were predicted by using miRwalk, miRDB, and Targetscan database, respectively. Moreover, the gene ontology and KEGG pathway enrichment established that the regulating functions and signaling pathways of these miRNAs contribute to follicular atresia initiation and cell fate. In conclusion, this study provides new insights into the changes of miRNAs in early atretic follicles to demonstrate their molecular regulation in ovarian follicular atretic initiation

Vulnerability of Eco-Hydrological Environment in the Yellow River Delta Wetland

We investigated the relationship between groundwater head and oceanic tidal fluctuations in the Yellow River Delta wetland through on-site hydrological monitoring. Shallow groundwater heads were obviously affected by oceanic tide along the coastal zone. The ranges of the wetland zone can be readily assessed by measuring fluctuation amplitudes or lags. The results show that the influence radius is approximately 12 km to 18 km (when the correlation coefficient is 0.7 to 0.8) under the joint actions of oceanic tide and shallow groundwater seepage flow in clayey silt coastal wetland. A cross-sectional sketch of the coastal wetland model is developed based on monitoring data of groundwater and oceanic tidal fluctuations to study the vulnerability of the eco-hydrological environment in the Yellow River Delta wetland. The coastal wetland consists of three zones (the groundwater seepage zone, the tidal-induced transitional zone, and the tidal zone) with distinctly different hydraulic properties. Analytical solutions are used to estimate the vulnerability of the ecohydrological environment in the wetland aquifer located in the NE part of the Yellow River Delta wetland, Shandong Province, China. Our results show that changes in the shallow groundwater quality of the wetland are significantly affected by natural factors, such as strong cutoff in the lower reaches, storm tides, and human engineering activities. The northern coastal wetland may be submerged without damp proof when the height of a storm tide reaches 2.4 m. The depth of shallow groundwater and the salinity gradient are key factors that contribute to the vulnerability of the ecological environment. The vulnerability of the eco-hydrological environment is derived from the joint actions of groundwater dynamics, hydrochemistry, and tidal-induced processes under sedimentary stress and water pressure.We investigated the relationship between groundwater head and oceanic tidal fluctuations in the Yellow River Delta wetland through on-site hydrological monitoring. Shallow groundwater heads were obviously affected by oceanic tide along the coastal zone. The ranges of the wetland zone can be readily assessed by measuring fluctuation amplitudes or lags. The results show that the influence radius is approximately 12 km to 18 km (when the correlation coefficient is 0.7 to 0.8) under the joint actions of oceanic tide and shallow groundwater seepage flow in clayey silt coastal wetland. A cross-sectional sketch of the coastal wetland model is developed based on monitoring data of groundwater and oceanic tidal fluctuations to study the vulnerability of the eco-hydrological environment in the Yellow River Delta wetland. The coastal wetland consists of three zones (the groundwater seepage zone, the tidal-induced transitional zone, and the tidal zone) with distinctly different hydraulic properties. Analytical solutions are used to estimate the vulnerability of the ecohydrological environment in the wetland aquifer located in the NE part of the Yellow River Delta wetland, Shandong Province, China. Our results show that changes in the shallow groundwater quality of the wetland are significantly affected by natural factors, such as strong cutoff in the lower reaches, storm tides, and human engineering activities. The northern coastal wetland may be submerged without damp proof when the height of a storm tide reaches 2.4 m. The depth of shallow groundwater and the salinity gradient are key factors that contribute to the vulnerability of the ecological environment. The vulnerability of the eco-hydrological environment is derived from the joint actions of groundwater dynamics, hydrochemistry, and tidal-induced processes under sedimentary stress and water pressure

Drought and Waterlogging Characteristics during the Growth Period of

In summer maize growth period, the water supply and demand ratio is regarded as the evaluation index of drought and waterlogging for the summer maize in Liaocheng City. Using GIS, statistics, agrometeorology and other methods, we analyze the precipitation during the summer maize growth period in Luxi Plains from 1961 to 2011. Through the calculation of drought and waterlogging index, it indicates that the disasters of drought and waterlogging frequently occur during the summer maize growth period, mainly affected by the drought; the frequency of occurrence of drought accounts for 80.4%, that is, it is very prone to serious drought phenomenon, seriously affecting the normal growth and development of summer maize during the seedling period. With global warming, the industrial and domestic water demand is increasing year by year, so it is extremely difficult to increase the water diversion to solve the problem of water shortage for the growth of summer maize. Finally we put forth the following recommendations: (i) Selecting drought-resistant varieties, and improving the water resource use efficiency; (ii) Promoting the water and fertilizer coupling, sprinkler irrigation, drip irrigation, micro-irrigation and other water-saving irrigation technologies, and improving the water use efficiency; (iii) Promoting the ditch, ridge and laminating cultivation technology, reducing the field evapotranspiration, keeping warming and conserving moisture, and saving water resources; (iv) Strengthening the construction of water conservancy facilities, so that it can be irrigated during drought and drained during waterlogging; (v) During dry season, timely organizing artificial rainfall operation, and increasing precipitation in arid areas to ease drought; (vi) Rationally exploiting the groundwater, and improving the underground water use efficiency

Effect of Contamination on Electric Field Distribution of DC Voltage Divider

In order to research the influence of the contamination around the external insulating surface of DC voltage divider with different types in the electic field distribution by using the finite element method, a two dimensional axisymmetric model of the DC voltage divider in Longquan convertor station is built. Through the calculation comparison in electrostatic and quasi-electrostatic field, the relative dielectric constant of the dry, moist and the non-uniform mixed contamination layer is discussed under the condition of the material parameters is known in quasi-electrostatic field .Analysis shows that for dry contamination，the field type has no influence on the electric field distribution when the parameters of the materials are same. While for moist contamination，the relative dielectric constant in electrostatic field should be set according to the material resistivity in quasi-electrostatic field and the actual condition. The calculation of the non-uniform contamination prove that the materials parameters in electrostatic filed is reasonable

BeiDou Satellite Unhealthy States and the Impact on System Performance

The BeiDou system satellites may be unhealthy due to many reasons, affecting system performance in different ways. Therefore, it is important to analyze the causes and characteristics of the satellites’ unhealthy states. In this study, these states are classified into five types based on the broadcast ephemeris. Three criteria are presented, based on which a general classification method is proposed. Data from July 2017 to June 2018 are analyzed to validate the method, from which we know that the average unhealthy duration due to satellite maneuvers is much longer than the duration of unhealthy states related to satellite orbit or clock anomalies, and the other unhealthy states may be caused by inbound or outbound satellites. Statistics show that most of the time, the number of unhealthy satellites is no more than two and the average positioning accuracy in the service area will decrease by no more than 0.75 and 1.2 meters when one or two BDS satellites are unhealthy, respectively

Study on temperature distribution and smoke diffusion characteristics of cable shafts in high-rise buildings

The smoke and poisonous gas produced during combustion is one of the direct hazards of cable fire. For power cables laid vertically in the cable shaft of high-rise buildings, the chimney effect will speed up the spread and expand the harm of cable fire. The paper proposes a simulation method based on fire dynamics theory to analyze the diffusion and spread characteristics of cable fire. First, a three-dimensional model of the double-floor cable shaft with multiple cables laid vertically inside was built in the paper. Second, with the abnormal heating caused by overload or insulation breakdown as the excitation condition, the development process of cable fire is simulated. The diffusion of smoke and gas during the whole combustion process is studied and discussed. Then, the paper compares the simulation results of the model with different fire blocking materials. The simulation results show that the application of blocking materials will cause differences between the spread of fire and flue gases, and the difference can be used to evaluate the quality and performance of the fire blocking material. Finally, A test platform is constructed to verify the validity of the simulation analysis

A GIS Partial Discharge Defect Identification Method Based on YOLOv5

The correct identification of partial discharge types is of great significance to the stable operation of GIS. In order to improve the recognition accuracy and result of partial discharge, and to meet the requirements of real-time monitoring of GIS equipment, this paper proposes a GIS partial discharge defect recognition model based on YOLOv5. First, the GIS partial discharge simulation experiment is established to create the dataset of partial discharge PRPD map. Then, a YOLOv5-based GIS partial discharge defect recognition model is constructed, and different training methods are used to optimize the parameters of the model. By comparing with target detection models based on other deep learning methods, such as Faster-RCNN and YOLOv4, the YOLOv5 model discussed in the paper has significantly improved the recognition efficiency and recognition accuracy, in which mAP value is 95.89% and FPS is 28.89. In addition, the model can realize the distinction and identification of multiple PD types in a single PRPD map. At last, the YOLOv5-based GIS partial discharge defect identification model is applied to the test in a 500 kV substation. The model accurately determines the type of GIS partial discharge, which verifies the accuracy and validity of the model