College education and the poor in China: documenting the hurdles to educational attainment and college matriculation

Xiaobing Wang,Chengfang Liu,Linxiu Zhang,Renfu Luo,Thomas Glauben,Yaojiang Shi,Scott Rozelle,Brian Sharbono 서울대학교 교육연구소 2011 Asia Pacific Education Review Vol.12 No.4

Although universities have expanded in size, it is unclear whether the poor have benefited. If there are high returns to college education, then increasing access of the poor to college has important welfare implications. The objective of this paper is to document the rates of enrollment into college of the poor and to identify the hurdles to doing so. Relying on several sets of data, including a survey of college students from universities in three poor provinces in China, we have found that the college matriculation rate of the poor is substantially lower than students from non-poor families; the same is true for rural women and minorities. Clearly, there are barriers that are keeping the rural poor out. The paper also demonstrates that the real hurdles are not during the years of secondary schooling or at the time of admissions to college. The real impediments keeping the rural poor from pursuing a college education arise long before high school-as early as preschool and elementary school years-and are present throughout the entire schooling system.

A Dynamic Linearization Modeling of Thermally Induced Error Based on Data-Driven Control for CNC Machine Tools

Puling Liu,Xiao-dong Yao,Guang-yan Ge,Zhengchun Du,Xiaobing Feng,Jianguo Yang 한국정밀공학회 2021 International Journal of Precision Engineering and Vol.22 No.2

This paper proposes a novel dynamic linearization modeling method for machine tool thermal errors based on data-driven control theory, with improved accuracy and robustness under various practical working conditions of machine tool. The nonlinear, quasi-static and pseudo-hysteric characteristics of the machine tool temperature field are identified as the main causes for poor robustness in conventional thermal error mathematical models. The theoretical and practical difficulties in applying conventional modeling approaches based on the model-based control theory are demonstrated using two types of CNC machine tools as examples. The data-driven control theory is applied to dynamic linearization modeling and the developed data model has shown significant improvement over the general dynamic model in terms of model accuracy and robustness. The feasibility and effectiveness of the proposed dynamic linearization modeling method has been verified using two experiments, demonstrating excellent robustness and ability to adapt to various machining conditions and to improve machining accuracy.

Dynamic processes of hyporheic exchange and temperature distribution in the riparian zone in response to dam-induced water fluctuations

Dongsheng Liu,Jian Zhao,Xiaobing Chen,Yingyu Li,Shipan Weiyan,Mengmeng Feng 한국지질과학협의회 2018 Geosciences Journal Vol.22 No.3

We examined the dynamic processes of hyporheic exchange and temperature distribution in a riparian zone in response to low-temperature water fluctuations downstream of the Xin’an River Dam, China, using analytical and mainly hydrodynamic methods. For this purpose, we installed six HM21 piezometers (R, P1–P5) between the river water and the groundwater at an interval of approximately 2 m perpendicular to the flow path. We also installed 20 PT100 thermistors (T1–T20) along the transect at depths of 1.19 m to 3.58 m and monitored the temperatures of river and air. Water levels and temperatures were automatically logged every 5 min by the real-time system from November to December 2014 and sent to the remote platform through the remote terminal unit. Results revealed that the intensity and direction of the hyporheic exchange (Q) between the river water and the groundwater varied periodically (t = 1 d) with the water level of the river. In each cycle, the Q was in a counterclockwise loop curve with the water level of the river and with the non-uniform distribution along the transect perpendicular to the river, which showed that the farther the lateral exchange was away from the river, the lower its intensity and the more hysteretic the alteration of its direction. The daily exchange width and residence time had no necessary connection with the average river stage, but mainly depended on the amplitude of the fluctuating river stage and the duration of river infiltration and established a strong linear relationship with their product. The temperature distribution of the riparian aquifer was mainly affected by the surface radiation and river water infiltration. It was characterized as “cool on the surface and warm at the bottom” in the vertical direction and could be divided into low-, medium-, and high-temperature zones along the horizontal direction. The horizontal infiltration distance (L) increased by power functions with the increase in infiltration rate (v) and decrease in river temperature (T).

Automatic Voltage Equalization Circuit Based on Multiple LC Resonant Units for Series-Connected Supercapacitor Strings

Zhang Xiaobing,Zhou Guohua,Liu Shuyi 대한전기학회 2023 Journal of Electrical Engineering & Technology Vol.18 No.3

The series-parallel switched-capacitor (SPSC) equalization circuit has high voltage stress on switch. To overcome this problem, an automatic voltage equalization circuit based on multiple LC resonant units is proposed for series-connected supercapacitor strings in this paper. The proposed equalization circuit shortens the equalization paths among cells and uses multiple LC resonant units, which improves the equalization speed. In the proposed equalization circuit, the maximum voltage stress on switch is only half of that in the SPSC equalization circuit. The configuration and operation principle of the proposed equalization circuit is presented. The power, equalization speed, and efficiency of the proposed equalization circuit are analyzed in detail. Based on the theoretical analysis, design considerations of the equalization circuit and design of modularized equalization circuit are proposed to optimize the equalization performance and to further decrease the voltage stress on switch. Simulation and experimental results are provided to verify the validity of the proposed equalization circuit. The results show that the proposed equalization circuit achieves fast equalization speed, high efficiency, and high equalization accuracy.

Effects of Dietary Flaxseed Lignan Extract on Symptoms of Benign Prostatic Hyperplasia

Wei Zhang,Xiaobing Wang,Yi Liu,Haimei Tian,Brent Flickinger,Mark W. Empie,Sam Z. Sun 한국식품영양과학회 2008 Journal of medicinal food Vol.11 No.2

A flaxseed lignan extract containing 33% secoisolariciresinol diglucoside (SDG) was evaluated for its abilityto alleviate lower urinary tract symptoms (LUTS) in 87 subjects with benign prostatic hyperplasia (BPH). A randomized, dou-ble-blind, placebo-controlled clinical trial with repeated measurements was conducted over a 4-month period using treatmentdosages of 0 (placebo), 300, or 600 mg/day SDG. After 4 months of treatment, 78 of the 87 subjects completed the study.For the 0, 300, and 600 mg/day SDG groups, respectively, the International Prostate Symptom Score (IPSS) decreased . 3.67.1.56, . 7.33. 1.18, and . 6.88. 1.43 (mean. SE, P. .100,. .001, and. .001 compared to baseline), the Quality of Lifescore (QOL score) improved by . 0.71. 0.23, . 1.48. 0.24, and . 1.75. 0.25 (mean. SE, P. .163 and .012 comparedto placebo and P. .103,. .001, and. .001 compared to baseline), and the number of subjects whose LUTS grade changedfrom “moderate/severe” to “mild” increased by three, six, and 10 (P. .188, .032, and .012 compared to baseline). Maximumurinary flows insignificantly increased 0.43. 1.57, 1.86. 1.08, and 2.7. 1.93 mL/second (mean. SE, no statistical sig-nificance reached), and postvoiding urine volume decreased insignificantly by . 29.4. 20.46, . 19.2. 16.91, and . 55.62.36.45 mL (mean. SE, no statistical significance reached). Plasma concentrations of secoisolariciresinol (SECO), enterodiol(ED), and enterolactone (EL) were significantly raised after the supplementation. The observed decreases in IPSS and QOLscore were correlated with the concentrations of plasma total lignans, SECO, ED, and EL. In conclusion, dietary flaxseed lig-nan extract appreciably improves LUTS in BPH subjects, and the therapeutic efficacy appeared comparable to that of com-monly used intervention agents of .1A-adrenoceptor blockers and 5.-reductase inhibitors.

Prognostic Perspectives of STING and PD-L1 Expression and Correlation with the Prognosis of Epstein-Barr Virus-Associated Gastric Cancers

( Qi Sun ),( Yao Fu ),( Xiaobing Chen ),( Lin Li ),( Hongyan Wu ),( Yixuan Liu ),( Haojun Xu ),( Guoren Zhou ),( Xiangshan Fan ),( Hongping Xia ) 대한소화기기능성질환·운동학회 2022 Gut and Liver Vol.16 No.6

Background/Aims: Epstein-Barr virus-associated gastric cancers (EBVaGCs) have unique molecular and clinicopathological characteristics. The cyclic GMP-AMP synthase-stimulator of interferon genes (STING) pathway is recently recognized as the critical innate immunity against pathogens and tumors. STING is also a master regulator in the cancer-immunity cycle and targeting STING could synergize with existing immune-checkpoint therapies. However, the role of STING in GC, especially in EBVaGC, and its correlation with programmed death-ligand 1 (PD-L1) remain largely unclear. Methods: We collected 78 cases of EBVaGCs and 210 cases of EBV-negative GC (EBVnGC) from a total of 1,443 cases of GC analyzed by EBV-encoded small RNA in situ hybridization. We investigated STING and PD-L1 expression and their concomitant prognostic value in EBVaGCs and EBVnGCs using tissue microarray and immunohistochemistry. The effects of STING and PD-L1 expression on the overall survival of patients with EBVaGC or EBVnGC were assessed by univariate and multivariate analysis. Results: We found that both STING and PD-L1 exhibited significantly higher expression in the EBVaGCs than that in the EBVnGCs. The expression of STING was positively correlated with that of PD-L1 in EBVaGCs. Simultaneous negative expression of STING and PD-L1, and positive expression of STING were independent prognostic risk factors for EBVaGC and EBVnGC, respectively. Conclusions: This is the first prognostic retrospective study of STING and PD-L1 expression and the prognosis among EBVaGC and EBVnGC. The expression and prognostic value of STING and PD-L1 are different in the two types of GCs. STING and PD-L1 are promising prognostic biomarkers and therapeutic targets for EBVaGC and EBVnGC. (Gut Liver 2022;16:875-891)

Metabolic Characteristic of the Liver of Dairy Cows during Ketosis Based on Comparative Proteomics

Xu, Chuang,Wang, Zhe,Liu, Guowen,Li, Xiaobing,Xie, Guanghong,Xia, Cheng,Zhang, Hong You Asian Australasian Association of Animal Productio 2008 Animal Bioscience Vol.21 No.7

The objective of the present study was to identify differences in the expression levels of liver proteins between healthy and ketotic cows, establish a liver metabolic interrelationship of ketosis and elucidate the metabolic characteristics of the liver during ketosis. Liver samples from 8 healthy multiparous Hostein cows and 8 ketotic cows were pooled by health status and the proteins were separated by two-dimensional-electrophoresis (2D-E). Statistical analysis of gels was performed using PDQuest software 8.0. The differences in the expression levels of liver proteins (p<0.05) between ketotic and healthy cows were identified by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF-TOF) tandem mass spectrometry. Five enzymes/proteins were identified as being differentially expressed in the livers of ketotic cows: expression of 3-hydroxyacyl-CoA dehydrogenase type-2 (HCDH), acetyl-coenzyme A acetyltransferase 2 (ACAT) and elongation factor Tu (EF-Tu) were down-regulated, whereas that of alpha-enolase and creatine kinase were up-regulated. On the basis of this evidence, it could be presumed that the decreased expression of HCDH, which is caused by high concentrations of acetyl-CoA in hepatic cells, in the livers of ketotic cows, implies reduced fatty acid ??oxidation. The resultant high concentrations of acetyl-CoA and acetoacetyl CoA would depress the level of ACAT and generate more ??hydroxybutyric acid; high concentrations of acetyl-CoA would also accelerate the Krebs Cycle and produce more ATP, which is stored as phosphocreatine, as a consequence of increased expression of creatine kinase. The low expression level of elongation factor Tu in the livers of ketotic cows indicates decreased levels of protein synthesis due to the limited availability of amino acids, because the most glucogenic amino acids sustain the glyconeogenesis pathway; thus increasing the level of alpha-enolase. Decreased protein synthesis also promotes the conversion of amino acids to oxaloacetate, which drives the Krebs Cycle under conditions of high levels of acetyl-CoA. It is concluded that the livers of ketotic cows possess high concentrations of acetyl-CoA, which through negative feedback inhibited fatty acid oxidation; show decreased fatty acid oxidation, ketogenesis and protein synthesis; and increased gluconeogenesis and energy production.

Association between Toll-Like Receptor 9 -1237T/C Polymorphism and the Susceptibility of Inflammatory Bowel Diseases: A Meta-Analysis

Bing Xia,Jian Shang,Xiaobing Wang,Wei Wang,Huaqin Pan,Shi Liu,Lixia Li,Liping Chen 연세대학교의과대학 2016 Yonsei medical journal Vol.57 No.1

Purpose: The -1237T/C polymorphism of the Toll-like receptor 9 (TLR9) gene has been implicated in the susceptibility of inflammatorybowel diseases (IBDs), but the results remain conflicting. We further investigated this association via meta-analysis. Materials and Methods: Multiple electronic databases were extensively searched until February, 2015. The strength of associationwas evaluated by calculating the pooled odds ratios (ORs) and 95% confidence intervals (CIs). Results: A total of 2987 cases and 2388 controls from eight studies were analyzed. Overall, association was found between TLR9 -1237T/C polymorphism and the risk of IBDs when all the studies were pooled (recessive model, OR: 1.59, 95% CI: 1.02–2.47, p=0.04; homozygote comparison, OR: 1.62, 95% CI: 1.04–2.52, p=0.03; allele model, OR: 1.13, 95% CI: 1.00–1.27, p=0.05). Stratificationby ethnicity indicated an association between TLR9 -1237T/C polymorphism and IBDs risk in Caucasians (recessive model,OR: 1.59, 95% CI: 1.02–2.47, p=0.04; homozygote comparison, OR: 1.62, 95% CI: 1.04–2.52, p=0.03; allele model, OR: 1.12, 95% CI: 1.00–1.27, p=0.05). When stratified by disease type, significant correlation were only found in the Crohn’s disease subgroup (recessive model, OR: 1.69, 95% CI: 1.05–2.73, p=0.03; homozygote model, OR: 1.74, 95% CI: 1.07–2.82, p=0.02; allele model, OR: 1.15, 95% CI: 1.01–1.32, p=0.04). Conclusion: The present study suggested that the TLR9 -1237T/C polymorphism might act as a risk factor in the development of IBDs, particularly in Caucasians.

The Silurian−Devonian granitoids in the East Kunlun orogenic belt, northern Qinghai-Tibetan plateau, China: origin and tectonic implications

Namkha Norbu,Yuegao Liu,Jinchao Li,Qunzi Jia,Wei Wang,Xiaobing Song,Yazhi Li,Huilei Kong,Yijie Gao,Xianzheng Guo,Xuegang Yao 한국지질과학협의회 2021 Geosciences Journal Vol.25 No.6

The East Kunlun orogenic belt (EKOB) is located in the northeastern part of the Qinghai-Tibetan Plateau, China. Voluminous Silurian–Devonian granitoids were formed during the Proto-Tethys Ocean subduction and collision process. In this study, zircon U-Pb age dating, in-situ Hf isotope analyses, and whole rock major and trace element analyses have been carried out on granitoids from the central to eastern EKOB. The formation ages of granodiorite in the Bairiqili area, the granodiorite in the Wulonggou area are 410 ± 2 Ma and 396 ± 1 Ma, respectively, and the granodiorites show I-type features. The Wulonggou syenogranite with a formation age of 398 ± 2 Ma has a high differentiation index (D.I. = 89.59–92.43), and may belong to the high fractionated I-type granite. The Lalangmai tonalite with a formation age of 423 ± 2 Ma has high Sr (339–590 μg/g), εHf(t) (1.5–7.3), and low Y (3.45–6.33 μg/g), which are similar to modern adakites. The Lalangmai tonalite is the latest adakite record during the Proto-Tethys evolution in EKOB. Combined with previous studies, it is concluded that the granitoids from Cambrian to Devonian divided into four episodes. The first episode (515–436 Ma) mainly consists of I-type island arc granites and adakite, which are formed in a subduction environment. The second episode (436–427 Ma) is characterized by the S-type granites related to the collision. The third episode (427–420 Ma) is the transition period between the collision and the post-collision environment. In the fourth episodes (420–385 Ma), granitoids were formed in post-collision extensional environment, which is characterized by I-type and A-type granites. The upwelling of asthenosphere material is likely caused by the collapse of the orogenic belt. After 420 Ma, I-type and A-type granites formed at different depths but in the same environment.

The Fate of Soybean Photosynthetic Carbon Varies in Mollisols Differing in Organic Carbon

Jian Jin,Guanghua Wang,Judong Liu,Zhenhua Yu,Xiaobing Liu,Stephen J Herbert 한국토양비료학회 2014 한국토양비료학회 학술발표회 초록집 Vol.2014 No.6