The LAMOST Survey of Background Quasars in the Vicinity of the Andromeda and Triangulum Galaxies -- II. Results from the Commissioning Observations and the Pilot Surveys

We present new quasars discovered in the vicinity of the Andromeda and Triangulum galaxies with the LAMOST during the 2010 and 2011 observational seasons. Quasar candidates are selected based on the available SDSS, KPNO 4 m telescope, XSTPS optical, and WISE near infrared photometric data. We present 509 new quasars discovered in a stripe of ~135 sq. deg from M31 to M33 along the Giant Stellar Stream in the 2011 pilot survey datasets, and also 17 new quasars discovered in an area of ~100 sq. deg that covers the central region and the southeastern halo of M31 in the 2010 commissioning datasets. These 526 new quasars have i magnitudes ranging from 15.5 to 20.0, redshifts from 0.1 to 3.2. They represent a significant increase of the number of identified quasars in the vicinity of M31 and M33. There are now 26, 62 and 139 known quasars in this region of the sky with i magnitudes brighter than 17.0, 17.5 and 18.0 respectively, of which 5, 20 and 75 are newly-discovered. These bright quasars provide an invaluable collection with which to probe the kinematics and chemistry of the ISM/IGM in the Local Group of galaxies. A total of 93 quasars are now known with locations within 2.5 deg of M31, of which 73 are newly discovered. Tens of quasars are now known to be located behind the Giant Stellar Stream, and hundreds behind the extended halo and its associated substructures of M31. The much enlarged sample of known quasars in the vicinity of M31 and M33 can potentially be utilized to construct a perfect astrometric reference frame to measure the minute PMs of M31 and M33, along with the PMs of substructures associated with the Local Group of galaxies. Those PMs are some of the most fundamental properties of the Local Group.Comment: 26 pages, 6 figures, AJ accepte

New genetic loci link adipose and insulin biology to body fat distribution.

Body fat distribution is a heritable trait and a well-established predictor of adverse metabolic outcomes, independent of overall adiposity. To increase our understanding of the genetic basis of body fat distribution and its molecular links to cardiometabolic traits, here we conduct genome-wide association meta-analyses of traits related to waist and hip circumferences in up to 224,459 individuals. We identify 49 loci (33 new) associated with waist-to-hip ratio adjusted for body mass index (BMI), and an additional 19 loci newly associated with related waist and hip circumference measures (P < 5 × 10(-8)). In total, 20 of the 49 waist-to-hip ratio adjusted for BMI loci show significant sexual dimorphism, 19 of which display a stronger effect in women. The identified loci were enriched for genes expressed in adipose tissue and for putative regulatory elements in adipocytes. Pathway analyses implicated adipogenesis, angiogenesis, transcriptional regulation and insulin resistance as processes affecting fat distribution, providing insight into potential pathophysiological mechanisms

Joint analysis of three genome-wide association studies of esophageal squamous cell carcinoma in Chinese populations

We conducted a joint (pooled) analysis of three genome-wide association studies (GWAS) 1-3 of esophageal squamous cell carcinoma (ESCC) in ethnic Chinese (5,337 ESCC cases and 5,787 controls) with 9,654 ESCC cases and 10,058 controls for follow-up. In a logistic regression model adjusted for age, sex, study, and two eigenvectors, two new loci achieved genome-wide significance, marked by rs7447927 at 5q31.2 (per-allele odds ratio (OR) = 0.85, 95% CI 0.82-0.88; P=7.72x10−20) and rs1642764 at 17p13.1 (per-allele OR= 0.88, 95% CI 0.85-0.91; P=3.10x10−13). rs7447927 is a synonymous single nucleotide polymorphism (SNP) in TMEM173 and rs1642764 is an intronic SNP in ATP1B2, near TP53. Furthermore, a locus in the HLA class II region at 6p21.32 (rs35597309) achieved genome-wide significance in the two populations at highest risk for ESSC (OR=1.33, 95% CI 1.22-1.46; P=1.99x10−10). Our joint analysis identified new ESCC susceptibility loci overall as well as a new locus unique to the ESCC high risk Taihang Mountain region

Scalar Perturbations of Black Holes in the f(R)=R&minus;2&alpha;R Model

In this paper, we study the perturbations of the charged static spherically symmetric black holes in the f(R)=R&minus;2&alpha;R model by a scalar field. We analyze the quasinormal modes spectrum, superradiant modes, and superradiant instability of the black holes. The frequency of the quasinormal modes is calculated in the frequency domain by the third-order WKB method, and in the time domain by the finite difference method. The results by the two methods are consistent and show that the black hole stabilizes quicker for larger &alpha; satisfying the horizon condition. We then analyze the superradiant modes when the massive charged scalar field is scattered by the black hole. The frequency of the superradiant wave satisfies &omega;&isin;(&mu;2,&omega;c), where &mu; is the mass of the scalar field, and &omega;c is the critical frequency of the superradiance. The amplification factor is also calculated by numerical method. Furthermore, the superradiant instability of the black hole is studied analytically, and the results show that there is no superradiant instability for such a system

Scalar Perturbations of Black Holes in the <inline-formula><math display="inline"><semantics><mrow><mi mathvariant="bold-italic">f</mi><mrow><mo mathvariant="bold">(</mo><mi mathvariant="bold-italic">R</mi><mo mathvariant="bold">)</mo></mrow><mo mathvariant="bold">=</mo><mi mathvariant="bold-italic">R</mi><mo mathvariant="bold">−</mo><mn mathvariant="bold">2</mn><mi mathvariant="bold-italic">α</mi><msqrt><mi mathvariant="bold-italic">R</mi></msqrt></mrow></semantics></math></inline-formula> Model

In this paper, we study the perturbations of the charged static spherically symmetric black holes in the f(R)=R−2αR model by a scalar field. We analyze the quasinormal modes spectrum, superradiant modes, and superradiant instability of the black holes. The frequency of the quasinormal modes is calculated in the frequency domain by the third-order WKB method, and in the time domain by the finite difference method. The results by the two methods are consistent and show that the black hole stabilizes quicker for larger α satisfying the horizon condition. We then analyze the superradiant modes when the massive charged scalar field is scattered by the black hole. The frequency of the superradiant wave satisfies ω∈(μ2,ωc), where μ is the mass of the scalar field, and ωc is the critical frequency of the superradiance. The amplification factor is also calculated by numerical method. Furthermore, the superradiant instability of the black hole is studied analytically, and the results show that there is no superradiant instability for such a system

Research Progresses of Flash Evaporation in Aerospace Applications

Liquid is overheated and evaporated quickly when it enters into the environment with lower saturation pressure than that corresponding to its initial temperature. This phenomenon is known as the flash evaporation. A natural low-pressure environment and flash evaporation have unique characteristics and superiority in high altitude and outer space. Therefore, flash evaporation is widely used in aerospace. In this paper, spray flash evaporation and jet flash evaporation which are two different forms were introduced. Later, key attentions were paid to applications of flash evaporation in aerospace. For example, the flash evaporation has been used in the thermal control system of an aircraft and the propelling system of a microsatellite and oil supply system of a rocket motor. Finally, the latest progresses in the calculation model and numerical simulation of flash evaporation were elaborated

Serum liver fibrosis markers predict hepatic decompensation in compensated cirrhosis

Abstract Background and aim The literature is sparse on the association between serum liver fibrosis markers and the development of hepatic decompensation in patients with compensated cirrhosis. We aimed to assessed whether the serum liver fibrosis markers are predictive of the occurrence of hepatic decompensation. Methods We ascertained 688 cirrhotic patients with varying etiologies, between December 2015 to December 2019. Serum hyaluronic acid (HA), laminin (LN), collagen IV (CIV), and N-terminal propeptide of type III collagen (PIIINP) levels were measured at enrollment. All subjects were followed for at least 6 months for occurrence of hepatic decompensation. Cox proportional hazard regression models were used to estimate the hazard ratios (HRs) of hepatic decompensation during follow-up. Results During a median follow-up of 22.0 (13.0–32.0) months, decompensation occurred in 69 (10.0%) patients. Multivariate analysis indicated that higher LN (HR: 1.008, 95% confidence interval [CI]: 1.002–1.014, P = 0.011) and CIV (HR: 1.004, 95% CI: 1.001–1.007, P = 0.003) levels were independently associated with hepatic decompensation. Furthermore, patients in the tertile 2 and tertile 3 groups for CIV levels had HRs of 4.787 (1.419, 16.152) (P = 0.012) and 5.153 (1.508, 17.604) (P = 0.009), respectively, for occurrence of decompensation event compared with those in the tertile 1 group. Conclusion Serum liver fibrosis markers, particularly in CIV, appeared to be reliable biomarkers of disease progression and liver decompensation in patients with compensated cirrhosis with varying etiologies

Mechanical Behavior and Thermal Stability of (AlCrTiZrMo)N/ZrO₂ Nano-Multilayered High-Entropy Alloy Film Prepared by Magnetron Sputtering

A new type of high-entropy alloy, a nitride-based (AlCrTiZrMo)N/ZrO2 nano-multilayered film, was designed to investigate the effect of ZrO2 layer thickness on the microstructure, mechanical properties, and thermal stability. The results show that when the thickness of the ZrO2 layer is less than 0.6 nm, it can be transformed into cubic-phase growth under the template effect of the (AlCrTiZrMo)N layer, resulting in an increased hardness. The (AlCrTiZrMo)N/ZrO2 film with a ZrO2 layer thickness of 0.6 nm has the highest hardness and elastic modulus of 35.1 GPa and 376.4 GPa, respectively. As the thickness of the ZrO2 layer further increases, ZrO2 cannot maintain the cubic structure, and the epitaxial growth interface is destroyed, resulting in a decrease in hardness. High-temperature annealing treatments indicate that the mechanical properties of the film decrease slightly after annealing at less than 900 °C for 30 min, while the mechanical properties decrease significantly after annealing for 30 min at 1000–1100 °C. The hardness and elastic modulus after annealing at 900 °C are still 24.5 GPa and 262.3 GPa, showing excellent thermal stability. This conclusion verifies the “template” effect of the nano-multilayered film, which improves the hardness and thermal stability of the high-entropy alloy