Common genetic variants in ADCY5 and gestational glycemic traits.

Two meta-analysis of genome wide association studies identified two variants at adenylate cyclase 5 (ADCY5) associated with type 2 diabetes mellitus, fasting and 2-hour glucose in non-pregnant individuals of European descent. The objective of our study was to explore the role of common variants in ADCY5 on gestational glycemic traits, including plasma glucose, insulin values, β cell function and insulin resistance in the fasted state as well as plasma glucose 1 hour after a 50-gram glucose challenge test among Chinese Han women. Homoeostasis model assessment (HOMA) was used to quantify β cell function (HOMA1-β and HOMA2-β) and insulin resistance (HOMA1-IR and HOMA2-IR). Thirty-five single nucleotide polymorphisms (SNPs) in ADCY5 were genotyped in 929 unrelated Chinese Han women with singleton pregnancies. Three SNPs (rs6797915, rs9856662 and rs9875803) displayed evidence for association with plasma glucose 1 hour after a 50-gram glucose challenge test (P = 0.042, 0.018 and 0.018, respectively), one (rs6777397) displayed evidence for association with HOMA1-β (P = 0.014), and one (rs6762009) displayed evidence for association with HOMA1-IR (P = 0.033). These results provide additional insight into the effects of genetic variation within ADCY5 in glucose metabolism, especially during pregnancy and in non-European descent populations

Paternal Genetic Structure of Hainan Aborigines Isolated at the Entrance to East Asia

BACKGROUND: At the southern entrance to East Asia, early population migration has affected most of the Y-chromosome variations of East Asians. METHODOLOGY/PRINCIPAL FINDINGS: To assess the isolated genetic structure of Hainan Island and the original genetic structure at the southern entrance, we studied the Y chromosome diversity of 405 Hainan Island aborigines from all the six populations, who have little influence of the recent mainland population relocations and admixtures. Here we report that haplogroups O1a* and O2a* are dominant among Hainan aborigines. In addition, the frequency of the mainland dominant haplogroup O3 is quite low among these aborigines, indicating that they have lived rather isolated. Clustering analyses suggests that the Hainan aborigines have been segregated since about 20 thousand years ago, after two dominant haplogroups entered East Asia (31 to 36 thousand years ago). CONCLUSIONS/SIGNIFICANCE: Our results suggest that Hainan aborigines have been isolated at the entrance to East Asia for about 20 thousand years, whose distinctive genetic characteristics could be used as important controls in many population genetic studies

Stealthy Configuration Optimization Design and RCS Characteristics Study of Microsatellite

Firstly, the radar cross section (RCS) test results of the stealthy microsatellite of TianXun-1(TX-1) in the anechoic chamber are compared with the RCS numerically simulated by the physical optics method, and the accuracy of the physical optical method is verified. On this basis, in order to improve the radar stealth performance of the microsatellite, a satellite stealth configuration optimization design method is proposed with the multi-prismatic stealth configuration of TX-1 as the initial configuration, and two olive stealth satellite configurations are obtained. By comparing the RCS simulation and radar detection probability of the optimized Olive-A and Olive-B satellite stealth configurations in multiple directions, it is demonstrated that the stealth performance of the Olive-B configuration is better. Finally, the anechoic chamber test is conducted on the metallic Olive-B model, and the test results show that the test results and simulation results of Olive-B are in good agreement, which again verifies that the stealth performance of Olive-B is better than that of TX-1 and Olive-A

Stealthy Configuration Optimization Design and RCS Characteristics Study of Microsatellite

Firstly, the radar cross section (RCS) test results of the stealthy microsatellite of TianXun-1(TX-1) in the anechoic chamber are compared with the RCS numerically simulated by the physical optics method, and the accuracy of the physical optical method is verified. On this basis, in order to improve the radar stealth performance of the microsatellite, a satellite stealth configuration optimization design method is proposed with the multi-prismatic stealth configuration of TX-1 as the initial configuration, and two olive stealth satellite configurations are obtained. By comparing the RCS simulation and radar detection probability of the optimized Olive-A and Olive-B satellite stealth configurations in multiple directions, it is demonstrated that the stealth performance of the Olive-B configuration is better. Finally, the anechoic chamber test is conducted on the metallic Olive-B model, and the test results show that the test results and simulation results of Olive-B are in good agreement, which again verifies that the stealth performance of Olive-B is better than that of TX-1 and Olive-A

Effect of Modifiers on the Rutting, Moisture-Induced Damage, and Workability Properties of Hot Mix Asphalt Mixtures

The present study aims to examine the effect of modifiers (Styrene-Butadiene-Styrene and crumb rubber) on the rutting, moisture-induced damage, and workability properties of hot mix asphalt (HMA) mixtures. In this study, three types—namely, control (CB), crumb rubber-modified (CRMB), and polymer-modified (PMB)—of mixtures/binders were evaluated. The rutting properties were evaluated using a wheel tracking device and the Multiple Stress Creep Recovery (MSCR) test. The moisture-induced damage properties were evaluated using the Indirect Tensile Strength (modified Lottman) and bitumen bond strength (BBS) tests. The workability properties were evaluated using densification indices (Bahia and locking point method) and a viscosity test. The results indicate that CRMB mixtures were less workable and exhibited a better resistance to rutting than the PMB and CB mixtures. Further, the PMB mixtures had increased resistance to moisture-induced damage, while the effect of the CRMB mixtures was negligible compared to the CB mixtures

Viscoelastic Analysis of the Damping Asphalt Mixtures (DAMs) Made with a High Content of Asphalt Rubber (AR)

Damping asphalt mixtures (DAMs) have been developed to resist vibration and noise caused by traffic loads, and the ultimate design goal in this process is to increase damping. However, while optimizing its damping characteristics, the viscoelastic properties are not yet clear. In the present study, two DAMs are designed based on the open-graded (OG) aggregate structure, and the viscoelastic properties are evaluated subsequently by the dynamic mechanical testing. The results show that the proposed mix-design method for DAMs can meet the mechanical requirements specified in the standards; DAMs are detected to have higher phase angle and lower stiffness modulus compared with traditional mixtures, and the antifatigue performance is excellent but resistance to rutting may face challenges

Development of an Ensemble Intelligent Model for Assessing the Strength of Cemented Paste Backfill

Cemented paste backfill (CPB) is an eco-friendly composite containing mine waste or tailings and has been widely used as construction materials in underground stopes. In the field, the uniaxial compressive strength (UCS) of CPB is critical as it is closely related to the stability of stopes. Predicting the UCS of CPB using traditional mathematical models is far from being satisfactory due to the highly nonlinear relationships between the UCS and a large number of influencing variables. To solve this problem, this study uses a support vector machine (SVM) to predict the UCS of CPB. The hyperparameters of the SVM model are tuned using the beetle antennae search (BAS) algorithm; then, the model is called BSVM. The BSVM is then trained on a dataset collected from the experimental results. To explain the importance of each input variable on the UCS of CPB, the variable importance is obtained using a sensitivity study with the BSVM as the objective function. The results show that the proposed BSVM has high prediction accuracy on the test set with a high correlation coefficient (0.97) and low root-mean-square error (0.27 MPa). The proposed model can guide the design of CPB during mining

Modelling Hydration Swelling and Weakening of Montmorillonite Particles in Mudstone

It is of paramount importance to understand the hydration swelling and weakening properties of clay minerals, such as montmorillonite, to determine their mechanical responses during deep underground argillaceous engineering. In this study, the mineral components and microscopic structure of mudstone were characterised using X-ray powder diffraction and field-emission scanning electron microscopy. Experimental schemes were devised to determine the properties of mudstone under the influence of underground water and stress; these involved compacting montmorillonite particles with various water contents and conducting uniaxial compression tests. Experimental results demonstrated that compaction stress changes the microscopic structure of the montmorillonite matrix and affects its properties, and stress independency was found at particular water and stress conditions. Two equations were then obtained to describe the swelling and weakening properties of the montmorillonite matrix based on the discrete element method; further, the hydration swelling equation represents the linear decrease in the density of the montmorillonite matrix with an increase in the water content. It was also determined that the water dependency of uniaxial compressive strength can be described by negative quartic equations, and the uniaxial compressive strength of the montmorillonite matrix is just 0.04 MPa with a water content of 0.6. The experimental results are in good agreement with the calculated solutions and provide an important experimental basis to the understanding of the mechanical properties of montmorillonite-rich mudstones under the influence of underground water and stress

Stability Control for the Rheological Roadway by a Novel High-Efficiency Jet Grouting Technique in Deep Underground Coal Mines

In maintaining the efficiency of coal mining, the stability of roadway plays a significant role, as it is closely related to the production of coal and the safety of personnel. In deep underground coal mines, the rheological deformation of roadway normally occurs, which affects its service life. To address this problem, in this paper, a novel high-efficiency Jet Grouting (JG) technique was presented, and its control effect on roadway stability was investigated. A creep test of a coal specimen in a laboratory scale was performed, and its creep behavior was revealed. The rheology of the coal mass surrounding the roadway was further analyzed according to the field-monitoring results of roadway deformation. A time-dependent numerical model with a Burger-creep visco-plastic model (CVISC) was established and validated by comparing the calculated displacement with in-situ measurement. The JG technique was tested in the field, and its applicability and practicability were confirmed. According to the validated model and field test results of JG, a numerical model with CVISC by JG support was established to analyze the effect of JG on the roadway. The results showed that the JG support can effectively reduce roadway deformation, optimize stress conditions, and reduce the extent of the plastic zone around the roadway. The rheological properties of the soft coal roadway were constrained and long-term stability was ensured. This pioneering work can guide the application of JG for the stability control of roadways and promote the sustainability of coal mining efficiently