南京江心洲鸟类群落特征

2004～2006年,分冬夏两季对南京江心洲4种典型生境(居民区、农田区、林区及湿地区)的鸟类资源进行了调查。共记录鸟类67种,隶属10目25科。对冬夏两季不同生境中鸟类群落的密度、现存生物量、多样性指数、均匀度、优势度的对比研究表明,冬季鸟类密度、物种多样性和均匀度均高于夏季,而优势度、现存生物量则夏季高于冬季。在不同生境中,林区鸟类密度、多样性指数最高;居民区优势度最高;均匀度指数冬季林区最高,夏季居民区最高。     

芜湖市冬夏季鸟类多样性分析

2004年5月至2005年2月,对芜湖市4种典型生境（农田居民区、城市园林、河漫滩湿地和河流湿地）的冬夏季鸟类进行调查,并探讨4种生境冬夏两季鸟类多样性指数.共记录鸟类117种,隶属于15目31科.农田居民区、城市园林和河漫滩湿地夏季鸟的种类数、G-F指数高于冬季,河流湿地冬季鸟的种类数、Shannon-Wiener指数、Pielou指数均明显高于夏季.城市园林鸟的种类数、G-F指数最高,河漫滩湿地Shannon-Wiener指数、Pielou指数最高.夏季的农田居民区和冬季的城市园林鸟类密度最大,分别为31.1140和42.9160 ind·hm^-2,而河流湿地鸟的种类数、密度、Shannon-Wiener指数、G-F指数均最低.增加栖息地异质性、减少人为干扰可以提高鸟类多样性.     

内蒙古乌兰察布地区鸟类区系组成及生态分布

2012年10月至2013年12月对内蒙古乌兰察布地区的鸟类区系及生态分布进行了调查研究。共记录到鸟类215种,隶属于17目48科。其中留鸟42种,夏候鸟101种,旅鸟67种,冬候鸟5种;繁殖鸟143种,构成区系的主体。繁殖鸟中古北界种类有118种,占繁殖鸟总数的82.5%,鸟类区系具有典型的古北界特征。国家Ⅰ级重点保护鸟类有5种,国家Ⅱ级重点保护鸟类有28种。依据地形地貌和植被类型,将该地区划分为湿地、林地、草地、农田、居民区5种生境,其中,湿地鸟类丰富度、多样性指数和均匀度指数最高,居民区鸟类丰富度、多样性指数和均匀度指数最低;优势度指数在居民区最高,在湿地生境中最低。从不同生境鸟类群落间β多样性的变化看,湿地与林地之间物种更替变化最大,群落相似性小;农田与居民区物种更替变化小,群落相似性大,与聚类分析的结果相一致。对该地区不同生境鸟类群落结构及其之间的关系进行了分析,探讨鸟类对栖息环境的选择以及鸟类与环境的关系。     

陕西省黄河湿地冬季鸟类群落初步研究

1998～2008年,采用直接计数法对陕西省黄河湿地冬季鸟类群落组成、鸟类物种多样性及数量变化进行了调查.在预先设置的5条调查样带中共记录到鸟类14目33科117种.观察结果表明,该地区鸟类多样性指数和均匀度指数分别为4.497和0.654.栖息地可分为人工渔塘、芦苇沼泽、滩涂湿地、农田和人工林5种类型.这些生境中鸟类组成及物种多样性差异均较大,其鸟类多样性指数分别为2.826、3.571、3.202、1.205、2.496,以芦苇沼泽中的鸟类多样性指数最高,滩涂湿地中鸟类数量最多,农田中鸟类优势度最高.通过对该地区鸟类群落组成及多样性分析研究以及黄河湿地冬季鸟类栖息地现状评价,为湿地鸟类资源的保护提供科学依据.     

内蒙古乌兰察布地区鸟类群落结构及季节变化

为了解内蒙古自治区乌兰察布地区的鸟类群落结构季节变化及其影响因素,于2012年10月至2013年12月,采用固定半径样点法和样带法对该地区6种生境类型的鸟类进行调查。共记录到鸟类17目45科153种,其中夏候鸟76种,旅鸟38种,留鸟34种,冬候鸟5种。春、夏、秋季均以夏候鸟为主,冬季则留鸟占优势。非雀形目鸟类所占比例明显高于雀形目。鸟类多样性指数为春季秋季夏季冬季,均匀性指数为春季夏季秋季冬季;聚类分析表明,春季和秋季鸟类群落结构最为相似。不同季节各生境鸟类群落结构亦存在差异,春、夏、秋季的湿地鸟类群落多样性均最高,而农田和居民区的鸟类群落较为相似。栖息地类型、食物资源及候鸟迁徙是该地区鸟类群落结构季节变化的主要影响因素。     

宁夏沙坡头自然保护区四种生境夏季鸟类群落变化

1999年夏季采用样线法调查了宁夏沙坡头自然保护区 4种生境鸟的种数和数量 ,并与 1986年用相同取样方法得到的数据 (Liu&Chang ,1990 )进行比较 ,以了解 13年间鸟类群落的变化并探讨其原因。 1999年共记录到 6 7种鸟 ,比 1986年新增 36种 ,同时减少 10种。荒漠生境鸟类的数量减少到不足 1986年的 5 0 % ,但种数、群落多样性和优势度与 1986年接近 ;湿地生境鸟类的种数和数量都增加 1倍多 ,群落多样性和优势度略有增加 ;固沙林生境鸟类的种数从 8种增加到 34种 (增加了食虫、荒漠鸟类 ) ,但数量略减少 ,群落多样性增加 6 7% ,优势度减少 6 3% ;村庄农田生境鸟类种数与 1986年接近 ,数量、群落多样性和优势度都减少。湿地鸟类群落的状态变好 ,是鱼塘水域增加的结果 ;固沙林鸟类群落的状况看似好转 ,但潜伏着虫害所致的荒漠化危机 ;村庄农田生境鸟类群落状态变差 ,与农村传统土房大量消失有关。     

广西山口红树林保护区海陆交错带夏季鸟类多样性调查

2011年6～8月采用样带法对山口地区海陆交错带的5种生境的鸟类多样性及群落相似性进行了研究,共记录到夏季鸟类31种,隶属于9目20科。在5种生境的鸟类群落中,红树林生境的鸟类群落Shannon-Wiener指数最高,农田生境的均匀度指数最高,农田生境和红树林生境的鸟类群落相似性指数最高,为0.759,桉树林生境和农田生境的相似性指数最低,为0.240。同时还对海陆交错带不同生境鸟类群落的多样性和相似性方面的问题进行了讨论。     

内蒙古伊金霍洛旗红海子湿地公园鸟类种类组成及生态分布

2012年10月—2013年9月,对红海子湿地公园鸟类资源进行调查。结果表明:共发现鸟类116种,隶属于16目36科,其中,夏候鸟49种,冬候鸟9种,留鸟24种,旅鸟34种;鸟类种类和数量有所增加;依据地形地貌和植被类型,在调查区选择了湿地、林地、草地和居民区4种生境,其中,湿地鸟类多样性指数(3.042)和均匀度指数(0.687)最高,居民区多样性指数(0.599)和均匀度指数(0.227)最低,优势度指数湿地最低(0.079),居民区最高(0.766),相似性指数林地和草地最高(0.667),湿地和居民区最低(0.204);本文对该湿地主要优势鸟种与环境的关系、湿地鸟类种类和数量较前几年增加的原因进行了分析,推测出水质变化可能是导致鸟类疾病发生和死亡的原因。     

扎兰屯成吉思汗机场鸟类多样性与鸟击防范

机场及其周边鸟类种类调查及其多样性研究对于新建机场开展鸟击防范工作具有重要意义。2015年1—12月,采用样线法和固定半径样点法对内蒙古扎兰屯成吉思汗机场及其周边8 km范围内的区域进行鸟类多样性调查。调查期间记录到鸟类82种,隶属于15目31科。根据对鸟类的群落结构分析:机场围界内春季的鸟类多样性指数(0.740)和均匀度指数(0.819)最高;冬季的优势度(0.683)最高;夏季的平均密度(2.83 ind·hm-2)最高。机场围界外:夏季湿地的多样性指数最高,为1.576;冬季的草地均匀度指数最高,为0.902;冬季的居民区优势度最高,为2.113;春季的湿地平均密度最高,为28.60 ind·hm-2。本文综合鸟类的体积、数量、出现次数、飞行高度、与机场的距离、出现的样带数以及是否集群7个因子对鸟类的危险值重新赋值并计算得出危险值,严重危险鸟类有普通鸬鹚(Phalacrocorax carbo)、麻雀(Passer montanus)、赤麻鸭(Tadorna ferruginea)等14种。根据调查结果提出不同季节、不同区域以及不同鸟种的针对性防范意见以及机场管理对策,为今后扎兰屯机场鸟击防范工作提供科学依据。     

江西齐云山自然保护区鸟类区系与多样性分析

2006年11月和2007年2～9月,对齐云山保护区的鸟类进行了本底调查和物种监测,共记录到鸟类257种,隶属于17目54科.其中留鸟120种,候鸟(夏候鸟、冬候鸟和旅鸟)137种;古北界种类97种(37.7%),东洋界种类141种(54.9%),广布种有19种(7.4%);国家重点保护鸟类8科34种;发现江西省新纪录鸟类4种.多样性分析结果显示,该区鸟类群落Shannon-Wiener指数、Pielou指数、和Simpson指数分别为3.875、0.791和0.964.从各生境群落多样性指数看,农田居民区中鸟类群落多样性指数最大,其次是灌草丛和阔叶林,溪流水域的多样性指数最小;优势度指数在不同生境的变化趋势与群落多样性指数相似;灌草丛中鸟类群落均匀度指数最高,阔叶林中的鸟类群落均匀度指数最低.通过与周边包括九连山、井冈山、江西武夷山和广东车八岭4个保护区的鸟类进行物种多样性G-F指数对比分析,得出齐云山鸟类多样性与九连山相当,而高于其他3个保护区.     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.     

Comparative morphology of the carpel in the Liliaceae: Hewardieae, Petrosavieae, and Tricyrteae

The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.     

Enterovirus 71 3C proteolytically processes the histone H3 N-terminal tail during infection

Highlights
1. The N-terminal tail of histone H3 is specifically cleaved during EV71 infection.
2. Viral protease 3C is identified as a protease responsible for proteolytically processing the N-terminal H3 tail.
3. Our finding reveals a new epigenetic regulatory mechanism for Enterovirus 71 in virus-host interactions.     

Detection of EBV and HHV6 in the Brain Tissue of Patients with Rasmussen’s Encephalitis

Rasmussen’s encephalitis (RE) is a rare pediatric neurological disorder, and the exact etiology is not clear. Viral infection may be involved in the pathogenesis of RE, but conflicting results have reported. In this study, we evaluated the expression of both Epstein-Barr virus (EBV) and human herpes virus (HHV) 6 antigens in brain sections from 30 patients with RE and 16 control individuals by immunohistochemistry. In the RE group, EBV and HHV6 antigens were detected in 56.7% (17/30) and 50% (15/30) of individuals, respectively. In contrast, no detectable EBV and HHV6 antigen expression was found in brain tissues of the control group. The co-expression of EBV and HHV6 was detected in 20.0% (6/30) of individuals. In particular, a 4-year-old boy had a typical clinical course, including a medical history of viral encephalitis, intractable epilepsy, and hemispheric atrophy. The co-expression of EBV and HHV6 was detected in neurons and astrocytes in the brain tissue, accompanied by a high frequency of CD8⁺ T cells. Our results suggest that EBV and HHV6 infection and the activation of CD8⁺ T cells are involved in the pathogenesis of RE.     

Perinatal Vertical Transmission of Chikungunya Virus in Ruili,a Town on the Border between China and Myanmar

正Dear Editor,Chikungunya virus (CHIKV), an arbovirus in the family of Togaviridae, genus Alphavirus, is transmitted by the A.aegyptii or A. albopictus mosquito, and causes disease in humans characterized by fever, rash, and arthralgia (Silva and Dermody 2017; Suhrbier 2019). It was first reported in 1953 in Tanzania, and caused only a few outbreaks and sporadic cases in Africa and Asia in last century. However, in the epidemic in 2004, CHIKV acquired mutations that conferred enhanced transmission by the A. albopictus mosquito(Schuffenecker et al. 2006). Since then, it has successively caused outbreaks in Africa, the Indian Ocean, South East Asia, the South America, and Europe (Zeller et al. 2016).     

Development of a Novel Reverse Transcription Loop-Mediated Isothermal Amplification Method for Rapid Detection of SARS-CoV-2

In conclusion, the novel visual RT-LAMP assay is a simple, rapid, and sensitive approach for detection of SARS-CoV-2, and it is ready for application in primary care and community hospitals or health care centers, and even patients' own houses in response to the current SARS-CoV-2 epidemic because the assay does not require sophisticated equipment and skilled personnel. Furthermore, it is also ready to be used in fields for screening samples from wild animals and environments to facilitate the identification of potential intermediate hosts that mediate the cross-species transmission of SARS-CoV-2 from bats to humans.