The One-Child Policy and Privatization of Education in China

China’s one-child policy is one of the most significant, yet controversial, programs of planned fertility. While the focus of the controversy is on the nature of the policy (for example, whether the policy is humane, or whether it violates the basic human rights of individual freedom), the impact of such population control program on China’s educational policy and practices is understudied. Moreover, the relationship between the one-child policy and the privatization of K-12 education in China remains insufficiently understood. Therefore, the purpose of this article is to address this gap in the literature and to explore the impact of one-child policy on privatization of education, and the transformation of education policy in China since 1979

Statistical Investigation of the Widths of Supra-arcade Downflows Observed During a Solar Flare

Supra-arcade downflows (SADs) are dark voids descending towards the post-reconnection flare loops and exhibit obvious variation in properties like width. However, due to the lack of further statistical studies, the mechanism behind such variations hitherto remains elusive. Here we statistically investigated widths of 81 SADs observed in one flare by the Solar Dynamics Observatory (SDO). For each of SADs, six moments were selected with equal time intervals to measure their widths at different stages of their evolution. It is found that most SADs show a roughly monotonous width decrease during their descents, while some SADs with small initial widths can have complex evolutions. 3D reconstruction results based on SDO and Solar Terrestrial Relations Observatory Ahead (STEREO-A) images and thermal properties analysis reveal that differences in magnetic and plasma environments may result in that SADs in the north are overall wider than those in the south. Additionally, correlation analysis between the width and other parameters of SADs was further conducted and revealed that: (1) SADs with different initial widths show no significant differences in their temperature and density evolution characteristics; (2) SADs with small initial widths usually appear in lower heights, where more frequent collisions between SADs could lead to their intermittent acceleration, width increment, and curved trajectories. These results indicate that SADs with different initial widths are produced the same way while different environments (magnetic field or plasma) could affect their subsequent width evolutions.Comment: 15 pages, 12 figures, 1 table. Accepted for publication in MNRA

Directed evolution of glycosyltransferase for the artificial biosynthesis of natural product glycosides

Over one fifth natural product drugs (including protein biopharmaceuticals), cosmetics, and nutraceuticals have a diverse set of sugars in their structures. These glycosylations dramatically influence the physicochemical and pharmacological properties of these compounds. Glycosyltransferases (GTs) offer very attractive approaches to the biosynthesis of complex glycosylated natural products. However, the limited number of available GTs, together with their instability and strict substrate specificity, have severely hampered the broad application of these enzymes. In the past few years, we have used directed evolution as a tool to tailor the GTs with desired substrate specificity and higher catalytic activity. Here I will introduce some of our efforts in 1) the semi-rational design of a glucosyltransferase UGT51 from S. cerevisiae to repurposing its promiscuous activity towards the biosynthesis of rare ginsenoside Rh2; and 2) the directed evolution of an α1,3-fucosyltransferase using a single-cell ultrahigh-throughput screening method. I will also discuss the development of new tools for the high-throughput screening method for GTs and the mechanistic insight we found during the evolution of these enzymes

Age-related sensitivity and pathological differences in infections by 2009 pandemic influenza A (H1N1) virus

<p>Abstract</p> <p>Background</p> <p>The highly pandemic 2009 influenza A H1N1 virus infection showed distinguished skewed age distribution with majority of infection and death in children and young adults. Although previous exposure to related antigen has been proposed as an explanation, the mechanism of age protection is still unknown.</p> <p>Methods</p> <p>In this study, murine model of different ages were inoculated intranasally with H1N1 (A/Beijing/501/09) virus and the susceptibility and pathological response to 2009 H1N1 infection were investigated.</p> <p>Results</p> <p>Our results showed that the younger mice had higher mortality rate when infected with the same dose of virus and the lethal dose increased with age. Immunohistochemical staining of H1N1 antigens in mice lung indicated infection was in the lower respiratory tract. Most bronchial and bronchiolar epithelial cells in 4-week mice were infected while only a minor percentage of those cells in 6-month and 1-year old mice did. The young mice developed much more severe lung lesions and had higher virus load in lung than the two older groups of mice while older mice formed more inducible bronchus-associated lymphoid tissue in their lungs and more severe damage in spleen.</p> <p>Conclusions</p> <p>These results suggest that young individuals are more sensitive to H1N1 infection and have less protective immune responses than older adults. The age factor should be considered when studying the pathogenesis and transmission of influenza virus and formulating strategies on vaccination and treatment.</p

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

MODIS Cloud Detection Evaluation Using CALIOP over Polluted Eastern China

Haze pollution has frequently occurred in winter over Eastern China in recent years. Over Eastern China, Moderate Resolution Imaging Spectroradiometer (MODIS) cloud detection data were compared with the Cloud&ndash;Aerosol Lidar with Orthogonal Polarization (CALIOP) for three years (2013&ndash;2016) for three kinds of underlying surface types (dark, bright, and water). We found that MODIS and CALIOP agree most of the time (82% on average), but discrepancies occurred at low CALIOP cloud optical thickness (COT &lt; 0.4) and low MODIS cloud top height (CTH &lt; 1.5 km). In spring and summer, the CALIOP cloud fraction was higher by more than 0.1 than MODIS due to MODIS&rsquo;s incapability of observing clouds with a lower COT. The discrepancy increased significantly with a decrease in MODIS CTH and an increase in aerosol optical depth (AOD, about 2&ndash;4 times), and MODIS observed more clouds that were undetected by CALIOP over PM2.5 &gt; 75 &mu;g m&minus;3 regions in autumn and particularly in winter, suggesting that polluted weather over Eastern China may contaminate MODIS cloud detections because MODIS will misclassify a heavy aerosol layer as cloudy under intense haze conditions. Besides aerosols, the high solar zenith angle (SZA) in winter also affects MODIS cloud detection, and the ratio of MODIS cloud pixel numbers to CALIOP cloud-free pixel numbers at a high SZA increased a great deal (about 4&ndash;21 times) relative to that at low SZA for the three surfaces. As a result of the effects of aerosol and SZA, MODIS cloud fraction was 0.08 higher than CALIOP, and MODIS CTH was more than 2 km lower than CALIOP CTH in winter. As for the cloud phases and types, the results showed that most of the discrepancies could be attributed to water clouds and low clouds (cumulus and stratocumulus), which is consistent with most of the discrepancies at low MODIS CTH

The relationship between plasma total testosterone and osteocalcin levels in males with newly diagnosed type 2 diabetes

Objective: To explore the relationship between plasma total testosterone and osteocalcin levels in males with newly diagnosed type 2 diabetes. Methods: A total of 146 males with newly diagnosed type 2 diabetes mellitus admitted from January 2018 through June 2020 were enrolled in the study. The patients were divided into four groups according to the level of osteocalcin: Q1 group (&lt;8.0 nmol/L), Q2 group (8.0-&lt;10.9) nmol/L, Q3 group (10.9-&lt;14.7 nmol/L) and Q4 group (&#x02265;14.7 nmol/L). The parameters of glucose and lipid metabolism and total testosterone levels were compared among groups and multiple linear regression was adopted to analyze the relationship of osteocalcin, total testosterone and other indexes. Results: It revealed that 58 (39.72%) patients also had hypogonadism, with the level of osteocalcin decreased to (11.27&#x000b1;5.62) nmol/L, significantly lower than patients with normal gonadal function(13.22&#x000b1;5.83 nmol/L)(P&lt;0.05). The total testosterone level in males with newly diagnosed type 2 diabetes increased along with osteocalcin (P&lt;0.05). Pearson correlation analysis showed that osteocalcin was positively correlated with total testosterone, serum creatinine and serum calcium (P&lt;0.05). Partial correlation analysis showed that after adjusting for age, body mass index (BMI), smoking, drinking, serum creatinine, blood calcium, total cholesterol, triglyceride, fasting insulin (FINS), glycosylated hemoglobin (HbA1c) and insulin resistance index(HOMR-IR), the level of osteocalcin was still positively correlated with total testosterone(P&lt;0.01). Patients with higher osteocalcin had higher levels of total testosterone and blood calcium(Q4 Group), but lower BMI, HOMR-IR, fasting blood glucose and HbA1c. Multiple stepwise regression analysis revealed that high osteocalcin was an independent factor for elevated level of total testosterone (&#x003b2; value 0.197, P&lt;0.05). Conclusions: Plasma total testosterone level is positively correlated with osteocalcin in newly diagnosed male patients with type 2 diabetes mellitus

Damping Properties of Arc Ion Plating NiCrAlY Coating with Vacuum Annealing

NiCrAlY coating was prepared on a stainless steel substrate by an arc ion plating machine and the annealing experiments were carried out at different temperatures using a tube furnace. The effects of annealing temperatures on the morphology, structure, chemical composition and phase structure of the coating were characterized by SEM, EDS and XRD, respectively. The change of microstructure is discussed. Dynamic mechanical analyzer results determined the suitable annealing temperature for the best damping performance. The effect of annealing temperature on the microstructure and damping properties of NiCrAlY coating are also discussed. The relationship between annealing temperature and damping properties are explained by microstrcuture, grain size and phase structure