Radio pulsar B0950++08: Radiation in Magnetosphere and Sparks above Surface

The nearby radio pulsar B0950$+$08 with full duty cycle is targeted by the Five-hundred-meter Aperture Spherical radio Telescope (FAST, 110 minutes allocated), via adopting polarization calibration on two ways of baseline determination, in order to understand its magnetospheric radiation geometry as well as the polar cap sparking. % The radiation of the main pulse could not be informative of magnetic field line planes due to its low linear polarization ($<10 \%$) and the position angle jumps, and the polarization position angle in the pulse longitudes whose linear fractions are larger than $\sim 30 \%$ is thus fitted in the classical rotating vector model (RVM). % The best RVM fit indicates that the inclination angle, $\alpha$, and the impact angle, $\beta$, of this pulsar are $100.5^{\circ}$ and $-33.2^{\circ}$, respectively, suggesting that the radio emission comes from two poles. % Polar cap sparking in the vacuum gap model, either the annular gap or the core gap, is therefore investigated in this RVM geometry, resulting in a high-altitude magnetospheric emission at heights from $\sim 0.25R_{\rm LC}$ to $\sim 0.56R_{\rm LC}$, with $R_{\rm LC}$ the light cylinder radius. % It is evident that both sparking points of the main and inter pulses are located mainly away from the magnetic pole, that is meaningful in the physics of pulsar surface and is even relevant to pulsar's inner structure.Comment: 13 pages, 9 figures, submitte

Comparison of the Effects of Different Testicular Sperm Extraction Methods on the Embryonic Development of Azoospermic Men in Intracytoplasmic Sperm Injection (ICSI) Cycles: A Retrospective Cohort Study

Background. The effects of different testicular sperm extraction methods on the embryonic development and clinical outcome of azoospermic men in intracytoplasmic sperm injection (ICSI) cycles have not been researched. Our goal was to evaluate the effect of different sperm retrieval methods used for patients with OA or NOA on the embryonic development and clinical outcomes during the ICSI cycles. Methods. This was a retrospective cohort study. A total of 530 azoospermic patients who underwent 570 ICSI cycles met the study criteria. ICSI was performed using testicular sperm by TESA in 282 cycles (TESA group); ICSI with testicular sperm by mTESE was performed due to NOA in 90 cycles (mTESE group); ICSI with testicular sperm by MESA was performed in 198 cycles (MESA group). The embryonic development and clinical outcomes of the three groups were counted. Results. The general characteristics of the three groups were comparable. Our findings showed that the three groups were matched in terms of infertility durations and age. The mean age and the mean BMI of the female partners were similar in the three groups. Also, our findings showed there were no significant differences in the three groups regarding day 3 of the menstrual cycle FSH and days of stimulation. The research results showed that the total dose of FSH and E2 on the HCG administration day was also not statistically different in the three groups. The number of oocytes retrieved had no significant differences in the three groups. However, the number of 2PNs per cycle and the number of cleavages per cycle were higher in the MESA group than in the other two groups; the TESA group and mTESE group were similar. The number of good quality D3 embryos and the number of good quality D5 embryos were significantly decreased in the mTESE group as compared to the other two groups. Good quality D3 embryos and the rate of good quality D5 embryos in the mTESE group were lower than those in the other two groups. Moreover, the clinical pregnancy rates of the TESA group (50.71%) and the MESA group (51.52%) were similar, but both were much higher than that of the mTESE group (32.22%). Conclusions. The mTESE provides a good clinical outcome for NOA patients with severe spermatogenic impairment, including the rate of good quality D3 embryos, the rate of good quality D5 embryos, and the clinical pregnancy rate. However, our data suggested that both the TESA and MESA groups had better embryonic development and clinical outcomes than the mTESE group

Damage Properties of the Block-Stone Embankment in the Qinghai–Tibet Highway Using Ground-Penetrating Radar Imagery

The block-stone embankment is a special type of embankment widely used to protect the stability of the underlying warm and ice-rich permafrost. Under the influence of multiple factors, certain damages will still occur in the block-stone embankment after a period of operation, which may weaken or destroy its cooling function, introducing more serious damages to the Qinghai–Tibet Highway (QTH). Ground-penetrating radar (GPR), a nondestructive testing technique, was adopted to investigate the damage properties of the damaged block-stone embankment. GPR imagery, together with the other data and methods (structural characteristics, field survey data, GPR parameters, etc.), indicated four categories of damage: (i) loosening of the upper sand-gravel layer; (ii) loosening of the block-stone layer; (iii) settlement of the block-stone layer; and (iv) dense filling of the block-stones layer. The first two conditions were widely distributed, whereas the settlement and dense filling of the block-stone layer were less so, and the other combined damages also occurred frequently. The close correlation between the different damages indicated a causal relationship. A preliminary discussion of these observations about the influences on the formation of the damage of the block-stone embankment is included. The findings provide some points of reference for the future construction and maintenance of block-stone embankments in permafrost regions

Route Plans for UAV Aerial Surveys according to Different DEMs in Complex Mountainous Surroundings: A Case Study in the Zheduoshan Mountains, China

Accurate and error-free digital elevation model (DEM) data are a basic guarantee for the safe flight of unmanned aerial vehicles (UAVs) during surveys in the wild, especially in moun-tainous areas with large topographic undulations. Existing free and open-source DEM data gen-erally cover large areas, with relatively high spatial resolutions (~90, 30, and even 12.5 m), but they do not have the advantage of timeliness and cannot accurately reflect current and up-to-date topographical information in the survey area. UAV pre-scanning missions can provide highly accurate and recent terrain data as a reference for UAV route planning and ensure security for subsequent aerial survey missions; however, they are time consuming. In addition, being limited to the electric charge of the UAV, pre-scanning increases the human, financial, and time consumption of field missions, and it is not applicable for field aerial survey missions in reality, unless otherwise specified, especially in harsh environments. In this paper, we used interferometric synthetic aper-ture radar (InSAR) technology to process Sentinel-1a data to obtain the DEMs of the survey area, which were used for route planning, and other free and open-source DEMs were also used for flightline plans. The digital surface models (DSMs) were obtained from the structure of the UAV pre-scan mission images, applying structure for motion (SfM) technology as the elevation reference. Comparing the errors between the InSAR-derived DEMs and the four open-source DEMs based on the reference DSM to analyze the practicability of flight route planning, the results showed that among the four DEMs, the SRTM DEM with a spatial resolution of 30 m performed best, which was considered as the first reference for UAV route plans when the survey area in complex mountainous regions is covered with a poor or inoperative network. The InSAR-derived DEMs from the Sentinel-1 images have great potential value for UAV flight planning, with a large perpendicular baseline and short temporal baseline. This work quantitatively analyzed the errors among the different DEMs and provided a discussion regarding UAV flightline plans based on external DEMs. This can not only effectively reduce the manpower, materials, and time consumption of field operations, improving the efficiency of UAV survey tasks, but it also broadens the use of InSAR technology. Furthermore, with the launch of high-resolution SAR satellites, InSAR-derived DEMs with high spatial and temporal resolutions provide an optimistic and credible strategy for UAV route planning with small errors

Route Plans for UAV Aerial Surveys according to Different DEMs in Complex Mountainous Surroundings: A Case Study in the Zheduoshan Mountains, China

Accurate and error-free digital elevation model (DEM) data are a basic guarantee for the safe flight of unmanned aerial vehicles (UAVs) during surveys in the wild, especially in moun-tainous areas with large topographic undulations. Existing free and open-source DEM data gen-erally cover large areas, with relatively high spatial resolutions (~90, 30, and even 12.5 m), but they do not have the advantage of timeliness and cannot accurately reflect current and up-to-date topographical information in the survey area. UAV pre-scanning missions can provide highly accurate and recent terrain data as a reference for UAV route planning and ensure security for subsequent aerial survey missions; however, they are time consuming. In addition, being limited to the electric charge of the UAV, pre-scanning increases the human, financial, and time consumption of field missions, and it is not applicable for field aerial survey missions in reality, unless otherwise specified, especially in harsh environments. In this paper, we used interferometric synthetic aper-ture radar (InSAR) technology to process Sentinel-1a data to obtain the DEMs of the survey area, which were used for route planning, and other free and open-source DEMs were also used for flightline plans. The digital surface models (DSMs) were obtained from the structure of the UAV pre-scan mission images, applying structure for motion (SfM) technology as the elevation reference. Comparing the errors between the InSAR-derived DEMs and the four open-source DEMs based on the reference DSM to analyze the practicability of flight route planning, the results showed that among the four DEMs, the SRTM DEM with a spatial resolution of 30 m performed best, which was considered as the first reference for UAV route plans when the survey area in complex mountainous regions is covered with a poor or inoperative network. The InSAR-derived DEMs from the Sentinel-1 images have great potential value for UAV flight planning, with a large perpendicular baseline and short temporal baseline. This work quantitatively analyzed the errors among the different DEMs and provided a discussion regarding UAV flightline plans based on external DEMs. This can not only effectively reduce the manpower, materials, and time consumption of field operations, improving the efficiency of UAV survey tasks, but it also broadens the use of InSAR technology. Furthermore, with the launch of high-resolution SAR satellites, InSAR-derived DEMs with high spatial and temporal resolutions provide an optimistic and credible strategy for UAV route planning with small errors

Radio Pulsar B0950+08: Radiation in the Magnetosphere and Sparks above the Surface

We observed the nearby radio pulsar B0950+08, which has a 100% duty cycle, using the Five-hundred-meter Aperture Spherical Radio Telescope. We obtained the polarization profile for its entire rotation, which enabled us to investigate its magnetospheric radiation geometry and the sparking pattern of the polar cap. After we excluded part of the profile in which the linear polarization factor is low (≲30%) and potentially contaminated by jumps in position angle, the rest of the swing in polarization position angle fits a classical rotating vector model (RVM) well. The best-fit RVM indicates that the inclination angle, α , and the impact angle, β , of this pulsar, are 100.°5 and −33.°2, respectively, suggesting that the radio emission comes from two poles. We find that, in such RVM geometry, either the annular vacuum gap model or the core vacuum gap model would require that the radio emissions come from a high-altitude magnetosphere with heights from ∼0.25 R _LC to ∼0.56 R _LC , with R _LC being the light cylinder radius. Both the main and interpulses’ sparking points are located away from the magnetic pole, which could relate to the physical conditions on the pulsar surface

Modified cementitious materials incorporating Al2O3 and SiO2 nanoparticle reinforcements: An experimental investigation

This research presents the improvement effect and influence mechanism of nano-Al2O3 (NA) and nano-SiO2 (NS) on concrete performance from the macro and micro scales. The crucial parameter investigated in this research is the various concentrations of the nano-reinforcement 1, 2, and 3 wt% of cement, the results show that NA and NS can improve the compressive strength and resistance to chloride penetration (RCP) ability of concrete, the amount of 1 and 2 wt% exhibiting the best effect, especially in terms of compressive strength, which can be increased by more than 20 %. As nanoscale particles, NA and NS can fill the capillary pores in concrete and can also promote the cement hydration to produce more C-S-H gel, thereby reducing the total porosity of concrete by about 2 %, making its internal pores and cracks less and the microstructure denser. Based on the correlation analysis, the most important factors affecting the compressive strength and RCP ability of concrete were found, and the linear relationship equation between compressive strength and RCP ability was obtained

MicroRNA Profiling Reveals an Abundant miR-200a-3p Promotes Skeletal Muscle Satellite Cell Development by Targeting TGF-β2 and Regulating the TGF-β2/SMAD Signaling Pathway

MicroRNAs (miRNAs) are evolutionarily conserved, small noncoding RNAs that play critical post-transcriptional regulatory roles in skeletal muscle development. Chicken is an optimal model to study skeletal muscle formation because its developmental anatomy is similar to that of mammals. In this study, we identified potential miRNAs in the breast muscle of broilers and layers at embryonic day 10 (E10), E13, E16, and E19. We detected 1836 miRNAs, 233 of which were differentially expressed between broilers and layers. In particular, miRNA-200a-3p was significantly more highly expressed in broilers than layers at three time points. In vitro experiments showed that miR-200a-3p accelerated differentiation and proliferation of chicken skeletal muscle satellite cells (SMSCs) and inhibited SMSCs apoptosis. The transforming growth factor 2 (TGF-&beta;2) was identified as a target gene of miR-200a-3p, and which turned out to inhibit differentiation and proliferation, and promote apoptosis of SMSCs. Exogenous TGF-&beta;2 increased the abundances of phosphorylated SMAD2 and SMAD3 proteins, and a miR-200a-3p mimic weakened this effect. The TGF-&beta;2 inhibitor treatment reduced the promotional and inhibitory effects of miR-200a-3p on SMSC differentiation and apoptosis, respectively. Our results indicate that miRNAs are abundantly expressed during embryonic skeletal muscle development, and that miR-200a-3p promotes SMSC development by targeting TGF-&beta;2 and regulating the TGF-&beta;2/SMAD signaling pathway

Bibliometric Analysis of the Permafrost Research: Developments, Impacts, and Trends

Permafrost is a significant part of the cryosphere, which has gained increasing attention from scientists, policy-makers, and the general public due to global warming, environmental degradation, water shortages, and intense human activities. Although many permafrost research review articles have been published, these studies were predominantly limited to either one subject or one field, while systematic studies about permafrost based on bibliometric analysis methods remain limited. We aim to fill this gap by conducting a bibliometric analysis of 13,697 articles in the field of permafrost research from 1942 to 2021, collected from the Web of Science core collection database. The results indicate that permafrost research is a typically multi-author, multi-country, and multi-institution cooperative field, involved in many research fields. The cumulative number of publications has presented an exponential increase over the past 80 years, with an average annual growth rate of 10.40%. Since 2000, China has seen a rapid growth in the number of publications per year, surpassing the USA in 2016 and leading in the years since then. In addition, the authors from China have great contributions in publications, and there is good room for permafrost development in the future according to the authors’ M-index ranking. After the analysis of authors’ keywords, we found that, compared to the conventional methods, machine learning and interferometric synthetic aperture radar (InSAR) are new technological approaches introduced in recent years, and the Qinghai–Tibet Plateau has become a popular study area. The results presented here can help related researchers, scholars, and students in the field to better understand the past developments, current status, and future trends of permafrost research. Furthermore, this paper presents and expands the general process of the bibliometric method used in permafrost studies, which can provide researchers with new inspirations and improve discipline research approach