The Role of PTHLH in Ovarian Follicle Selection, Its Transcriptional Regulation and Genetic Effects on Egg Laying Traits in Hens

In hens, follicle selection is an important process affecting egg laying traits. This study investigated the role of parathyroid hormone-like hormone (PTHLH) in chicken follicle selection, its transcriptional regulation and genetic effects on egg laying traits. PTHLH and its receptor PTH1R were mainly expressed in follicles of 6–8 mm in diameter, exhibits differential expression pattern in the theca and granulosa cells of pre- and hierarchal follicles. PTHLH stimulates the proliferation of follicular granulosa and theca cells, the expression of StAR and CYP11A1 mRNA and the production of progesterone (P4) in pre-hierarchal follicles. Treatment with FSH increased PTHLH mRNA expression in pre-hierarchal follicular theca cells and hierarchal follicular granulosa cells. Two critical regions regulating chicken PTHLH transcription were revealed, each of which harbored a SNP: C>T (chr1: 72530014) for AP-1 and a SNP: A>G (chr1: 72531676). Hens with diplotype AC/GT were younger at first laying and laid more eggs at 32 weeks. The haplotype (G-1827T-165) with double mutations had the greatest promoter activity of chicken PTHLH transcription. Collectively, PTHLH plays an important role in chicken follicle selection by stimulating cell proliferation and steroidogenesis. Polymorphisms in chicken PTHLH promoter region are associated with egg laying traits by affecting the binding of transcription factor AP-1

Prevalence of atrial fibrillation in different socioeconomic regions of China and its association with stroke: Results from a national stroke screening survey

Background: Atrial fibrillation (AF) is the most common sustained arrhythmia in clinical practice. This study aimed to estimate the prevalence of AF in different socioeconomic regions of China and identify its association with stroke, through a national survey. Methods: The study included 726,451 adults aged ≥40 years who were participants of the China National Stroke Screening and Prevention Project, a nationally representative cross-sectional study. Stepwise logistic regression analyses were conducted to investigate the association between AF and stroke. Results: The overall standardized prevalence rate of AF was 2.31%. The prevalence of AF was highest in high-income regions (2.54%), followed by middle-income regions (2.33%), and lowest in low-income regions (1.98%). Women had a higher prevalence of AF than men in all regions (low-income regions, 2.30% vs 1.65%; middle-income regions, 2.78% vs 1.89%; and high-income regions, 2.96% vs 2.12%). Compared with urban residents, the prevalence of AF among rural residents was higher in low- (2.03% vs 1.91%) and middle-income regions (2.69% vs 1.90%), but lower in high-income regions (2.44% vs 2.58%). Participants with AF were more likely to have a stroke than those without AF (9.48% vs 2.26%). After adjusting for age, sex, location, overweight or obese, smoking, drinking, physical inactivity, hypertension, diabetes, dyslipidemia, and a family history of stroke, results showed that AF was significantly associated with stroke. Conclusions: The prevalence of AF has increased in recent years, and it was positively correlated with socioeconomic status, sex (women), location (rural areas), and stroke

Confucius Institutes and the limitations of China’s global cultural network

The majority of Anglophone literature tends to portray Confucius Institutes as playing a successful role serving China’s interests in its foreign collaborations. So far, the threat of this institution has been largely stereotyped and even taken for granted. Few scholars question the influence and capacity of the institution on both global and local scales. Relying on cartograms, correlation and national image analyses as well as qualitative studies, this article examines the influence of Confucius Institutes as the institution globalized and localized. This article reports three main findings: (1) the geopolitical influence of Confucius Institutes is uneven in different regions and they are engaged in an ongoing process of geopolitical construction; (2) analyses of correlation with China’s national image show that not only does the influence of the institution vary in regions but also that the project could have a negative impact on bilateral cooperation, suggesting that, contrary to popular thinking, Confucius Institutes have not had a positive impact on China’s global interests; and (3) the capacity of the institutes in everyday operations is systematically limited, reflecting China’s inexperience in managing this global cultural network. Confucius Institutes are generous in making economic concessions but are hesitant during political negotiations, which can be said to mirror China’s patchy performance in economic and political reform

The ray-tracing mapping operator in an asymmetric atmosphere

In a spherically symmetric atmosphere, the refractive index profile is retrieved from bending angle measurements through Abel integral transform. As horizontal refractivity inhomogeneity becomes significant in the moist low atmosphere, the error in refractivity profile obtained from Abel inversion reaches about 10%. One way to avoid this error is to directly assimilate bending angle profile into numerical weather models. This paper discusses the 2D ray-tracing mapping operator for bending angle in an asymmetric atmosphere. Through simulating computations, the retrieval error of the refractivity in horizontal inhomogeneity is assessed. The step length of 4 rank Runge-Kutta method is also tested. (c) 2007 National Natural Science Foundation of China and Chinese Academy of Sciences. Published by Elsevier Limited and Science in China Press. All rights reserved

Original data used in figures of the paper

The data file includes all the experimental and theoretical data shown in Figure 5 to Figure 9

Robust Sliding Mode Control of the Permanent Magnet Synchronous Motor with an Improved Power Reaching Law

To improve the suppression ability of uncertain disturbance of the sliding mode control driving system of the surface-mounted permanent magnet synchronous motor (SPMSM) and to reduce the chattering of the control output, a robust sliding mode control strategy with an improved power reaching law (IPRL) is proposed in this paper. Compared with the traditional fast power reaching law (FPRL), the IPRL incorporates the sum of the power terms of the system state variables into the conventional power terms, and uses hyperbolic tangent saturation function to replace the piecewise function, which can effectively suppress the sliding mode chattering and improve the convergence speed of the system state to the sliding mode surface. Furthermore, the robust sliding mode speed controller and sliding mode current controller of the SPMSM are designed separately with the IPRL, and detailed simulation verification is carried out to reveal the effectiveness of the IPRL. Simulation and experimental results show that compared with the FPRL, the proposed IPRL can reduce the inherent chattering phenomenon in sliding mode control, and the IPRL-based speed and current control strategy can effectively improve the dynamic performance and robustness of the system

中国优质基础教育资源空间格局形成机制及综合效应

Education is not only important for strengthening a country's population quality and comprehensive power but key in reshaping the "man-land" relations in a country. This article reviews studies on the distribution of educational resources in both Chinese and Anglophone literature and summarizes the research gaps in the Chinese literature, which include but are not limited to the downplay of the analysis of mechanism and comprehensive effects of the spatial structure of educational resources. Employing different map-making technologies and mechanism-analysis methods, this article dives into three findings. First, though spatial features are slightly different between primary school level and middle school level, eastern regions generally have higher quality educational resources than western regions. In addition, urban agglomeration, including Beijing-Tianjin-Hebei, Shanghai-Ningbo-Hangzhou, and the Pearl River Delta, have an advantage in attracting and cultivating high-quality educational resources. Second, the quantity of high-quality primary school resources is positively correlated with annual per capita disposable income of urban households and number of full-time primary school teachers. The quantity of high-quality middle school resources is positively correlated with the comprehensive economic and social performance of the city. Third, when affected by multiple mechanisms, the spatial structure of China's high-quality educational resources is dynamic and deeply intertwines with the interrelations between cities as well as between the societies within each city. This article contributes both to the understanding of the unequal spatial structure of high-quality educational resources in China and to the analysis of complex socio-political effects on this transforming structure. Its findings encourage further research on the connection between the spatial structure of a region's educational resources and its cooperation and geopolitics as well as on the resulting social mobility among different social strata. Study limitations include: place-related elements, such as local political resources, were not sufficiently considered when selecting factors; there is a lack of longitudinal analysis; and not enough attention is paid to the combination of number-based data and geo-information-based data in analyses

Data from: Dynamic analysis of liquid annular seals with herringbone grooves on the rotor based on perturbation method

Annular seals have significant effects on the hydraulic and rotordynamic performances turbomachinery. In this paper, an analysis method for calculating the leakage rate and dynamic characterisitcs of liquid annular seals with herringbone grooves on the rotor is proposed and verified. Leakage flow rates and dynamic characteristics of the model seals under different operating conditions are theoretically analyzed and compared to those of the plain and spiral-grooved seals of the same size. Besides, the influence of geometric parameters such as spiral angle and the lengths of the constituent parts on the sealing and rotordynamic coefficients of seals with herringbone grooves are also discussed in this paper. The results show that seals with herringbone grooves have better sealing performance, while providing bigger support actions and better damping characteristics than the other two seal types under the same operating conditions. The seal geometric parameters including spiral angle, the lengths of the constituent parts and the clearance value have great influence on the dynamic characteristics of seals with herringbone grooves

Development of Equivalent Circuit Models of Permanent Magnet Synchronous Motors Considering Core Loss

Permanent magnet synchronous motor (PMSM) possesses the advantages of low power loss, high power density and high torque density and, hence, has achieved broad applications in both industrial drives and home appliances. With the increasing demands for high power density, the PMSM often operates at high speed and high frequency, leading to high power loss and temperature rise. Consequently, proper consideration of power loss, including the core loss, has attracted much attention for the modelling, designing, controlling and optimizing of PMSMs. However, the widely used equivalent circuit model, capable of providing good analysis results with fast calculation, often ignores the core loss, which may lead to unsatisfactory motor performance. This paper aims to investigate the development of equivalent circuit models, with predictable core loss for PMSMs, and proposes novel equivalent circuit models, which improve the core loss prediction accuracy in the load conditions. Some thoughts about the further improvement of the models are proposed and discussed