郑州地区夜鹭越冬生态调查

20 0 0～ 2 0 0 3年在郑州森林公园对夜鹭 (Nycticoraxnycticorax)的越冬种群进行了调查。结果表明 ,每年 9月越冬夜鹭在此集群 ,1 2月达到高峰 ,数量为 ( 1 697± 49)～ ( 1 95 0± 73 )只。越冬种群以成体为主 ,亚成体不超过种群的 7 84%。夜鹭在越冬地滞留的时间超过 5个月 ,至翌年 3月初离开越冬地迁往 7km外的市区繁殖。越冬期间 ,夜鹭白天静卧树枝上休息 ,日落后 8～ 3 2min外出觅食 ,日出前约 1h返回林中。隆冬季节部分夜鹭推迟觅食或并非每天外出觅食。在郑州森林公园安全越冬的个体仅为越冬最大种群的 3 4 46% ,导致夜鹭数量减少和死亡的原因主要为低温引起的食物短缺 ,致使部分个体扩散到其它区域或饥饿致死。本区为已报道的夜鹭越冬最北界 ,夜鹭由此产生一系列生态适应 ,白天活动减少 ,下树避风取暖 ,觅食习性也有所改变。     

苏州地区夜鹭越冬生态调查

夜鹭是苏州地区的冬候鸟,自1982年起,每年于9月末陆续飞至著名园林虎丘山的竹林中越冬,11—12月汇成大群,在1500平方米面积内所聚集的夜鹭有1400—1500只,其中幼鹭的数量在种群内约占三分之一。夜鹭白天停歇于枝头竹梢,静伏而眠,入夜由首鹭率领飞至太湖沿岸,觅食鲤、鲫、鲌、蟹条、青鱼和棒花鱼等,日出前仍循原路返回栖息地。越冬后的夜鹭于3月开始分批北迁,至5月上旬全部飞离虎丘山。近年来不仅有延迟飞迁日期的趋势,且有少数个体留居越冬地进行繁殖的情况。     

湖南江口苍鹭越冬生态观察

1992－1997年对湖南鸟洲自然保护区苍鹭越冬种群进行了观察。苍鹭每年11月上旬迁来鸟洲,次年4月中旬迁离,鸟洲保护区及其附近的芦苇沼泽地苍鹭越冬种群数量相对较多。     

四川成都大熊猫繁育研究基地夜鹭种群数量动态的观察

2003~2004年在成都大熊猫繁育研究基地对夜鹭种群数量动态作了观察。5个栖息区的种群数量随着区内生态条件不同而有差异。同一栖息区内种群数量同年变化范围较大,两年观察结果分别是:597~1168只和550~2091只;栖息区的种群密度为169.3~574.2只/hm2和183.3~916.7只/hm2。年度内种群数量变化具有一定规律性。     

黑龙江省熊类资源现状及其保护对策

黑龙江省现分布有 2种熊 ,棕熊 (Ursusarctoslasiotus)和黑熊 (Selenarctosthibetanusussuricus)。棕熊广泛分布于全省各个林区 ;黑熊在大兴安岭无分布 ,仅分布于小兴安岭和东部山地的张广才岭、老爷岭和完达山林区 ,其分布北界为北纬 48～ 49°,东经 1 2 8～ 1 2 9°附近。 2种熊的总分布区虽无明显变化 ,但集中分布区明显向大兴安岭、小兴安岭、东部山地的腹地退缩。 1 996～ 2 0 0 0年全省棕熊的分布数量为 (63 1±1 43 )头 (n =463 9) ,种群密度为 (0 0 0 2 2± 0 0 0 0 5 )头 km2 ;黑熊的分布数量为 (1 1 1 0± 2 93 )头 (n =463 9) ,种群密度为 (0 0 0 65± 0 0 0 1 7)头 km2 。全省森工国有林区熊类分布数量 (1 1 71± 2 98)头 (n =61 2 ) ,与1 992年该林区熊类调查结果 (3 0 5 7± 73 0头 ;n =2 1 3 6)相比较 ,全林区 6年间熊类数量减少了 1 886头 ,减少率达 61 7% ,年递减率为 1 6%。熊类资源呈锐减趋势。其主要原因为 :(1 )森林长期超量采伐引起熊类栖息生境总体质量下降 ;(2 )人类活动导致熊类栖息地片断化日趋严重 ;(3 )人为捕杀是造成熊类数量减少的直接原因。最后 ,提出了今后全省熊类保护管理的 5点建议。     

鄱阳湖保护区白琵鹭越冬种群分布

2007年10月至2010年3月3个冬季的调查显示,鄱阳湖国家级自然保护区白琵鹭(Platakakucorodia)种群数量在12月或1月达到峰值,3个越冬期最大种群数量分别为4 757只、10 385只和7 268只.大湖池、沙湖、常湖池是白琵鹭主要的栖息地,每个越冬期在这3个湖泊栖息的白琵鹭种群数量占保护区总数量的...     

四川青川县大熊猫种群分析

本文研究了青川县大熊猫冬春季对栖息地选择和 2 0世纪 70年代、80年代和 90年代栖息地分布和种群数量的变化 ,表明该地大熊猫冬春季对地形的选择主要为向阳的陡坡和斜坡或较干燥的阴坡 ,郁闭度 0 6以下 ,主要活动在海拔 2 2 0 0～ 2 80 0m区域 ;随着年代的递增 ,栖息地的面积日趋缩小 ,种群数量也逐步减少 ,分别为 114只、6 0只和47只 ;探讨了影响分布和数量的因素。     

太原市南郊大苇莺的种群数量及其环志

1985—1987年的5—9月和1991年的6—8月,在太原市南郊采用取样路线统计法对大苇莺的种群数量及环志进行了调查。调查表明该鸟为夏候鸟,5月中旬迁来,9月下旬迁离;其种群数量为24.73±1.26。每公顷鸟巢数为21.64个。环志后的成鸟与幼鸟,原地回收分别为2.06%和0.25%;幼鸟异地回收为0.25%。大苇莺的野外寿命至少6年。     

苏北地区丹顶鹤越冬种群数量及栖息地分布动态变化

利用资料追踪和历史时期土地利用变化数据深入研究了有资料记载以来苏北地区丹顶鹤越冬种群数量变化与栖息地分布的时空响应。结果显示,20世纪80年代之初,丹顶鹤越冬种群广泛分布于苏北地区,尤其是长江中下游的内陆湖泊、沼泽及江苏沿海滩涂湿地;20世纪90年代之后丹顶鹤分布区域逐渐向沿海滩涂湿地转移,主要分布于盐城市的射阳县境内;进入21世纪,丹顶鹤分布区域集中于盐城国家级珍禽保护区核心区。与此同时,丹顶鹤越冬种群数量也经历了十分明显的变化过程,与20世纪90年代相比,数量减少50%以上。丹顶鹤越冬种群数量及栖息地分布变化与栖息地分布点周围的土地利用方式及人为干扰有关,栖息地面积丧失和景观破碎化是丹顶鹤越冬种群数量减少的主要原因。     

内蒙古图牧吉大鸨种群动态及时空分布稳定性

大鸨（Otis tarda）是我国I级重点保护野生鸟类,对大鸨重要栖息地种群数量的变化趋势进行研究,将为大鸨及其栖息地的保护提供科学依据。2017年至2020年,对内蒙古图牧吉国家级自然保护区内及周边的大鸨种群数量动态进行了全面调查,共选择33个监测地点,对大鸨的数量、性别和分布地点进行了调查。结果表明,大鸨种群数量从2017年193只增加至2020年253只;大鸨1月的越冬种群数量从2017年67只减少至2019年55只,2020年重新恢复至67只。各月大鸨种群数量呈现较大的变化,数量高峰期分别是5月和10月。12月至次年2月,越冬种群数量50 ~ 70只。雌性大鸨从3月开始监测到,数量高峰值出现在4月和5月,达到50 ~ 70只,不同的年份略有差别;6月之后数量开始下降,至9月开始略有回升,在10月以后,野外基本观察不到雌性个体。在野外易于观察的4月,2017至2020年4年中雌雄比的平均值是1︰2。2017年和2018年,大鸨在马鞍山区域分布较多,数量也较为稳定。然而进入2019年,分布地点减少,这可能与当地人类活动的干扰有关;2020年保护区功能区进行了调整,将2014年调整出保护区范围的马鞍山区域重新划入保护区中,湿地和草地面积均有所增加,大鸨分布地点数量逐渐恢复。针对目前保护区存在的问题,建议采取退耕还草、加强保护空缺管理及禁牧等保护措施对大鸨及其栖息地进行保护。     

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.