Replication,pathogenicity, and transmission of SARS-CoV-2 in minks

Minks are raised in many countries and have transmitted severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to humans. However, the biologic properties of SARS-CoV-2 in minks are largely unknown. Here, we investigated and found that SARS-CoV-2 replicates efficiently in both the upper and lower respiratory tracts, and transmits efficiently in minks via respiratory droplets; pulmonary lesions caused by SARS-CoV-2 in minks are similar to those seen in humans with COVID-19. We further found that a spike protein-based subunit vaccine largely prevented SARS-CoV-2 replication and lung damage caused by SARS-CoV-2 infection in minks. Our study indicates that minks are a useful animal model for evaluating the efficacy of drugs or vaccines against COVID-19 and that vaccination is a potential strategy to prevent minks from transmitting SARS-CoV-2.     

论社会弱势群体的成因及其扶助措施

弱势群体问题关系着社会稳定的大局,已成为时下中国社会关注的热点问题。本文客观剖析了弱势群体产生的原因,提出了扶助社会弱势群体的具体措施。     

认证机构服务质量对关系质量影响实证研究

摘要：本文在认证行业领域,研究了认证机构服务质量对关系质量的影响。在认证机构服务质量4维度结构（即过程服务能力、过程交互质量、潜在服务能力和结果质量）及关系质量3维度结构（即合作性、适应性和关系氛围）的基础上,构建了认证机构服务质量对关系质量的影响模型。对721家企业的实证研究表明,过程服务能力、结果质量两个维度对认证机构和顾客之间的关系质量有显著影响,而过程交互质量、潜在服务能力两个维度对两者关系质量的影响不显著。最后对认证机构如何提高其服务质量,维持良好的顾客关系提出了建议。         

Shadow Play Drama Performed in China’s Xiaoyi

<正>Xiaoyi is a county located in the central part of north China’s Shanxi province. Over the sweep of history, many theatre forms were and developed in Xiaoyi, ...     

发展中国电子商务的几点思考

“电子商务”这个名词在我国已经不在是陌生的名词了,它已经在中国越来越被人们所认可.什么是电子商务?所谓电子商务(ElectronicCommerce)是利用计算机技术、网络技术和远程通信技术,实现整个商务(买卖)过程中的电子化、数字化和网络化。人们不再是面对面的、看着实实在在的货物、靠纸介质单据(包括现金)进行买卖交易。而是通过网络,通过网上琳琅满目的商品信息、完善的物流配送系统和方便安全的资金结算系统进行交易(买卖)。     

Genomic diversity and post-admixture adaptation in the Uyghurs

Population admixture results in genome-wide combinations of genetic variants derived from different ancestral populations of distinct ancestry, thus providing a unique opportunity for understanding the genetic determinants of phenotypic variation in humans. Here, we used whole-genome sequencing of 92 individuals with high coverage (30–60×) to systematically investigate genomic diversity in the Uyghurs living in Xinjiang, China (XJU), an admixed population of both European-like and East-Asian-like ancestry. The XJU population shows greater genetic diversity, especially a higher proportion of rare variants, compared with their ancestral source populations, corresponding to greater phenotypic diversity of XJU. Admixture-induced functional variants in EDAR were associated with the diversity of facial morphology in XJU. Interestingly, the interaction of functional variants between SLC24A5 and OCA2 likely influences the diversity of skin pigmentation. Notably, selection has seemingly been relaxed or canceled in several genes with significantly biased ancestry, such as HERC2–OCA2. Moreover, signatures of post-admixture adaptation in XJU were identified, including genes related to metabolism (e.g. CYP2D6), digestion (e.g. COL11A1), olfactory perception (e.g. ANO2) and immunity (e.g. HLA). Our results demonstrated population admixture as a driving force, locally or globally, in shaping human genetic and phenotypic diversity as well as in adaptive evolution.     

Simultaneous changes in seed size,oil content and protein content driven by selection of SWEET homologues during soybean domestication

Soybean accounts for more than half of the global production of oilseed and more than a quarter of the protein used globally for human food and animal feed. Soybean domestication involved parallel increases in seed size and oil content, and a concomitant decrease in protein content. However, science has not yet discovered whether these effects were due to selective pressure on a single gene or multiple genes. Here, re-sequencing data from >800 genotypes revealed a strong selection during soybean domestication on GmSWEET10a. The selection of GmSWEET10a conferred simultaneous increases in soybean-seed size and oil content as well as a reduction in the protein content. The result was validated using both near-isogenic lines carrying substitution of haplotype chromosomal segments and transgenic soybeans. Moreover, GmSWEET10b was found to be functionally redundant with its homologue GmSWEET10a and to be undergoing selection in current breeding, leading the the elite allele GmSWEET10b, a potential target for present-day soybean breeding. Both GmSWEET10a and GmSWEET10b were shown to transport sucrose and hexose, contributing to sugar allocation from seed coat to embryo, which consequently determines oil and protein contents and seed size in soybean. We conclude that past selection of optimal GmSWEET10a alleles drove the initial domestication of multiple soybean-seed traits and that targeted selection of the elite allele GmSWEET10b may further improve the yield and seed quality of modern soybean cultivars.     

论师资结构对高校体育教育可持续发展的影响

文章运用文献资料法、调查法和数理统计法,通过对甘肃高校公共体育课开设状况及特点、教师比例、学历、职称、年龄结构、教学能力和科研能力等现状的调查与分析.提出了通过增加教师数量,稳定教师队伍,提高教师素质等促进学校体育工作发展的措施.     

六味地黄汤对运动性疲劳大鼠肾脏损害的影响

目的:观察六味地黄汤对运动性疲劳大鼠血Cystatin C和血β2-微球蛋白(β2-MG)的影响,探讨其对运动性疲劳大鼠肾脏的保护机制。方法:采用大鼠游泳运动建立疲劳模型,随机分为安静组(A)、运动即刻组(B)、运动后24h组(C)、六味地黄汤安静组(D)、六味地黄汤运动即刻组(E)、六味地黄汤运动后24h组(F),A、D组休息状态,B、C、E、F组游泳训练。采用颗粒增强透射免疫比浊法和放射免疫法测定大鼠血Cystatin C和β2-MG。结果:A、C、D、F组血Cystatin C和β2-MG值明显低于B、E组(P<0.01)。另外,与B组相比,E组血Cystatin C和β2-MG值明显降低。结论:六味地黄汤可降低血清Cystatin C和β2-MG,直接或间接维持肾小球的通透性,对肾脏损伤有保护作用,对运动性疲劳有消除和延缓作用。     

冰上杂技音乐剧 《爱丽丝梦游仙境》的审美体现

大型冰上杂技音乐剧《爱丽丝梦游仙境》是由黑龙江冰尚杂技舞蹈演艺制作有限公司与融创集团联袂推出的一部精品力作。该剧根据英国童话大师刘易斯·卡罗尔的《爱丽丝漫游仙境》和《爱丽丝镜中奇遇记》及迪士尼以此素材拍摄的3D电影改编而成。经过剪头绪、立主脑,简化了原著的故事情节和人物关系。