四川卧龙国家级自然保护区三种高山同域鸡形目鸟类的时空生态位比较

高海拔山区气候条件恶劣, 资源匮乏, 探究同域分布的近缘物种如何利用有限的资源以实现稳定共存, 对于了解高山生态系统生物多样性格局的形成和维持机制具有重要意义。鸡形目鸟类飞行能力弱, 属于典型的地栖物种, 生态位空间相对狭窄, 可能面临更高的种间竞争压力。本研究旨在比较几种同域分布的鸡形目鸟类的时空生态位, 为了解高山生态系统同域物种的共存机制提供新的研究案例。2020年4-9月, 研究人员在四川卧龙国家级自然保护区海拔3,300-4,200 m的高山区域进行了野外调查, 通过样线法和样方法对鸡形目鸟类群落优势物种绿尾虹雉(Lophophorus lhuysii)、雉鹑(Tetraophasis obscurus)和雪鹑(Lerwa lerwa)繁殖期的微生境进行调查, 使用红外相机对其活动节律进行监测, 并运用核密度估计法从微生境利用和日活动节律两个生态维度进行了种间生态位比较。结果显示, 雪鹑在微生境利用和日活动节律上均与其他两个物种存在显著差异。绿尾虹雉与雉鹑在微生境的利用上具有相似偏好; 但绿尾虹雉的早活动高峰晚于雉鹑, 晚活动高峰早于雉鹑, 表现出显著的种间日活动节律差异; 然而, 整合两个维度后, 绿尾虹雉和雉鹑的整体生态位仍然高度重叠, 没有显著分化。本研究表明高山鸡形目物种间的生态位分化体现于多个不同的生态维度, 并且不同物种之间的分化方式有所差异。在空间和时间生态位上的显著分化使雪鹑与同域物种间的竞争压力相对较小, 有利于其实现稳定共存。而绿尾虹雉与雉鹑的整体生态位高度重叠, 建议进一步对其食性开展研究, 探讨营养生态位上的潜在种间分化。     

中国生物多样性核心监测指标遥感产品体系构建与思考

生物多样性的稳定维持关乎人类生存发展与地球健康。生物多样性核心监测指标(Essential Biodiversity Variables, EBVs)旨在结合地面调查与遥感技术, 为大尺度、长时间序列的生物多样性监测提供新的解决方案。然而, 目前学界仍然缺乏一套国家尺度标准化EBVs遥感监测产品数据集, 以进行生物多样性评估。本研究旨在对中国生物多样性核心监测指标遥感产品进行体系构建与思考, 首先综述了目前EBVs的遥感研究概况, 并根据EBVs研究文献的数量进行调研分析; 同时, 本文在已有遥感生物多样性产品优先标准的基础上, 添加了“可重复性”的新标准, 并据此构建了中国EBVs遥感产品体系与监测数据集的指标清单, 最终对中国EBVs遥感研究存在的问题进行思考与讨论。本研究可为中国的生物多样性遥感监测提供科学依据, 有望为中国生物多样性政策的制定提供支撑。     

生命早期益生菌干预预防儿童过敏性疾病的Meta分析CSCD

目的 系统评价生命早期益生菌干预预防儿童过敏性疾病的疗效。方法 采用计算机检索万方、中国知网、CBM、PubMed、Cochrane library、Embase和Web of science数据库有关生命早期益生菌干预对儿童过敏性疾病预防作用的随机对照试验研究,检索时间为建库至2020年9月,应用Stata 11.0软件对纳入研究进行Meta分析。结果 最终纳入36篇随机对照试验文献。Meta分析结果显示,生命早期益生菌干预对预防湿疹(RR=0.84,95%CI:0.73~0.98,P=0.022)和食物过敏(RR=0.82,95%CI:0.68~0.98,P=0.028)作用显著,但对预防哮喘(RR=0.92,95%CI:0.80~1.06,P=0.231)、喘息(RR=0.98,95%CI:0.89~1.07,P=0.635)、过敏性鼻炎(RR=0.99,95%CI:0.78~1.26,P=0.945)和过敏性鼻结膜炎(RR=1.13,95%CI:0.86~1.49,P=0.376)无显著作用。结论 生命早期益生菌干预对儿童湿疹、食物过敏具有预防作用,但对哮喘、喘息、过敏性鼻炎和过敏性鼻结膜炎无预防作用,对于其机制仍需进一步研究。     

Interaction between GAMs and Mean Flow Shear During SMBI Injection into HL-2A Tokamak

Plasma Physics Reports - The interactions among geodesic acoustic modes (GAMs), mean flow, and mean flow shear were investigated using Langmuir probe arrays under periodic supersonic molecular beam...     

Ungulate bocaparvovirus 4 and rodent bocavirus are different genotypes of the same species of virus

Bocaviruses are associated with many human infectious diseases, such as respiratory tract infections, gastroenteritis, and hepatitis. Rats are known to be reservoirs of bocaviruses, including rodent bocavirus and rat bocavirus. Recently, ungulate bocaparvovirus 4, a known porcine bocavirus, has also been found in rats. Thus, investigating bocaviruses in rats is important for determining the origin of the viruses and preventing and controlling their transmission. To the best of our knowledge, no study to date has investigated bocaviruses in the livers of rats. In this report, a total of 624 rats were trapped in southern China between 2014 and 2017. Liver and serum samples from rats were tested for the prevalence of bocaviruses using PCR. Sequences related to ungulate bocaparvovirus 4 and rodent bocavirus were detected in both liver and serum samples. Interestingly, the prevalence of ungulate bocaparvovirus 4 (reference strain:KJ622366.1) was higher than that of rodent bocavirus (reference strain:KY927868.1) in both liver (2.24% and 0.64%, respectively) and serum samples (2.19% and 0.44%, respectively). The NS1 regions of ungulate bocaparvovirus 4 and rodent bocavirus related sequences displayed over 84% and 88% identity at the nucleic acid and amino acid levels, respectively. Furthermore, these sequences had similar genomic structure, genomic features, and codon usage bias, and shared a common ancestor. These viruses also displayed greater adaptability to rats than pigs. Our results suggested that ungulate bocaparvovirus 4 and rodent bocavirus may originate from rats and may be different genotypes of the same bocavirus species.     

Albumin uptake and distribution in the zebrafish liver as observed via correlative imaging

Although liver transport routes have been extensively studied in rodents, live imaging under in situ and in vivo conditions of large volumes is still proven to be difficult. In this study, we took advantage of the optical transparency of zebrafish and their small size to explore their usefulness for correlative imaging studies and liver transport experimentations. First, we assessed the micro-architecture of the zebrafish liver and compared its fine structure to the rodent and humans’ literature. Next, we investigated the transport routes and cellular distribution of albumin using combined and correlative microscopy approaches. These methods permitted us to track the injected proteins at different time points through the process of liver uptake and clearance of albumin.We demonstrate strong structural and functional resemblance between the zebrafish liver and its rodents and humans’ counterparts. In as short as 5?min post-injection, albumin rapidly accumulated within the LSECs. Furthermore, albumin entered the space of Disse where it initially accumulated then subsequently was taken up by the hepatocytes. We propose the zebrafish as a viable alternative experimental model for hepatic transport studies, allowing swift multimodal imaging and direct quantification on the hepatic distribution of supramolecular complexes of interest.     

Expression and functional analysis of flotillins in Dugesia japonica

FLOTILLIN-1 and FLOTILLIN-2 are membrane rafts associated proteins that have been implicated in insulin and growth factor signaling, endocytosis, cell migration, proliferation, differentiation, cytoskeleton remodeling and membrane trafficking. Furthermore, FLOTILLINs also play important roles in the progression of cancer and neurodegenerative diseases. In this study, the roles of flotillins are investigated in planarian Dugesia japonica. The results show that Djflotillin-1 and Djflotillin-2 play a key role in homeostasis maintenance and regeneration process by regulating the proliferation of the neoblast cells, they are not involved in the maintenance and regeneration of the central nervous system in planarians.     

A correlational study between serum asymmetric dimethylarginine level and impaired glucose tolerance patients associated with obesity

Asymmetric dimethylarginine (ADMA) plays a vital role in the regulation of insulin sensitivity and has been shown as a potential marker for various disease, including type 2 diabetes mellitus (DM2). However, the correlation between ADMA and impaired glucose tolerance (IGT) and obesity has not been studied. A total of 195 subjects were involved in our study. The characteristics of the subjects in the study cohort were measured and analyzed. We found that the serum ADMA and C-reactive protein levels were significantly increased in IGT and diabetic patients, whereas the levels of lipoprotein A and adiponectin were decreased, especially in diabetic patients with obesity. The serum ADMA level was positively correlated to a homeostatic model assessment for insulin resistance, and multivariate regression analysis further indicated that ADMA was an independent factor for DM patients with obesity. Our study expands the understanding of the complicated relationship between obesity, insulin resistance, IGT, and ADMA. In addition, we demonstrated that the serum ADMA level could serve as a diagnositic biomarker of the early signs for IGT patients with obesity.