北京小龙门发现淡尾鹟莺

我们在北京小龙门林场(40°00'N,115°26'E)发现淡尾鹟莺(Seicercus soror):2011年6月发现1只;2012年6月发现5只.该鸟在海拔约1 100 m的阔叶林中上部活动,生境中乔木多为核桃楸(Juglans mandshurica)和辽杨(Populus maxuimowiczii). 北京小龙门个体灰色,顶冠纹不超过眼先、金黄色的眼圈完整、无明显翼斑、外侧两对尾羽内羽片末端白色.这些特征可与金眶鹟莺种组(Seicercus complex)的其他物种相区分,确认其为淡尾鹟莺.对2只个体各10句鸣唱进行测量,语句长度分别为(1.086±0.060)s(平均值±标准差)和(1.179±0.056)s;最高频率分别为(7.532±0.742) kHz和(7.351±0.591)kHz;最低频率分别为(2.476±0.312) kHz和(2.442±0.297) kHz.     

棕眉柳莺鸣唱声谱分析及其地理差异的初步研究

2002、2005、2007年5-8月,在甘肃莲花山、宁夏贺兰山和内蒙阿拉善贺兰山等自然保护区对棕眉柳莺(Phylloscopus armandii)的鸣唱进行了采集,共录到18只108 min的鸣声.通过声谱分析,棕眉柳莺鸣唱的频率范围在2.63-6.32 kHz之间;音素数平均为5.56±2.47(n=124);持续时间为(1.07 4-0.30)s(rg=124).最长可达2.68 s.棕眉柳莺鸣唱音节之间的间隔时间差异较大,范围在2～18 8之间;从18只个体共589个音节中总结出61种音节类型,其中37种为共享音节,24种为特有音节,分别占总数的60.7%和39.3%.不同棕眉柳莺个体的鸣唱音节类型组成不同,没有任何两只棕眉柳莺个体的音节曲目完全一致.莲花山和内蒙贺兰山两个地区内个体之间的音节相似性系数存在显著差异(P=0.001).通过对棕眉柳莺鸣唱的地理变异分析,发现越是邻近分布的个体其鸣唱也越相似.     

斑背大尾莺繁殖期鸣声行为分析

2009年5-7月,在辽宁双台河口保护区录制了20只繁殖期斑背大尾莺雄性个体的鸣声.根据行为特征,该鸟鸣声定义为3种鸣声类型:求偶炫耀鸣唱、报警声和联络声.利用Wavesurfer软件对20只斑背大尾莺雄性个体543个鸣声的句子持续时间、句子音节个数、音节持续时间、音节间隔时间等4个参数进行分析测量,发现求偶炫耀鸣唱由节奏逐渐加快的前部句子和音节组成复杂的主体部两个句子组成; 报警声和联络声的句子均由单音节组成.音节类型总数为38种,其中包括前部句子的音节类型6种.采用单因素方差分析(one-way ANOVA)对求偶炫耀鸣唱的4个参数进行差异性检验发现,不同个体的各个参数均呈极显著差异(P<0.01).     

腾冲拟髭蟾繁殖期鸣声特征

为了研究腾冲拟髭蟾(Leptobrachium tengchongense)的繁殖期鸣声特征,2018年2月27日,利用TASCAM DR-40专业录音机,在野外录制了6只个体总共78个有效鸣声,随后利用Raven Pro?v.1.5声音分析软件对鸣声进行分析。结果表明,繁殖期的雄性腾冲拟髭蟾发出求偶鸣声及竞争鸣声两种不同类型鸣声,均为单音节鸣叫,且鸣声主频均为1.31～1.50 kHz。求偶鸣声的时长为(147±30.1)ms,所含脉冲数为(15±2.4)pulses/s;竞争鸣声为雄蟾听到附近其他个体鸣叫后所发出的较拖长的鸣声,其鸣声时长为(610±187.0)ms,所含脉冲数为(28±10.7)pulses/s。不同个体之间的鸣叫时长和鸣叫间隔存在差异,这可能与个体的体型大小有关,但需要更多的数据去证实。我们根据调查结果,分析讨论当前腾冲拟髭蟾所面临的主要威胁及其保育策略。     

高黎贡山火尾绿鹛的鸣声特征分析

鸣声在鸟类通讯、配偶吸引和领域保卫等方面均有重要作用。本研究旨在探讨雀形目火尾绿鹛(Myzornispyrrhoura)繁殖期的鸣声类型及其生物学意义。于2013和2014年的3至7月在云南高黎贡山片马垭口、独龙江垭口录制了成鸟(n=30)、3个家庭的幼鸟(n=6)和1巢雏鸟(n=2)的鸣声。依据鸣声发出时的个体行为特征,将录制的成鸟鸣声分为3种类型,即联络鸣叫、报警鸣叫和雄性鸣唱。其中,雄鸟鸣唱的语图明显比其他鸣叫声更复杂。而样本量较多的多声联络鸣叫和报警鸣叫的声学特征在个体间有显著差异。雏鸟随着日龄的增加,其鸣声的音节数和持续时间均增加,但峰频率随日龄增加而降低,至20日龄雏鸟和幼鸟鸣叫特征十分相似。野外观察发现,火尾绿鹛在繁殖期的鸣唱较少,其原因尚需进一步研究。     

白头鹎的鸣唱结构及其鸣唱微地理变异

对武汉市区白头鹎(Pycnonotus sinensis)的鸣唱类型和音节类型进行了统计、分析,并按照采样地点划分为组(微地理种群),对组间、组内不同白头鹎个体间的鸣唱差异进行了探讨.分析来自市区5个样点的26只雄性白头鹎的667个鸣唱,共发现18种基本鸣唱型、53种音节类型.每只雄性白头鹎具有1-3种基本鸣唱型,每只个体能唱6.7(4-1 4)种音节类型.平均每个鸣唱由5.0(3-11)个音节、4.6(3-8)种音节类型组成.白头鹎的鸣唱顺序模式为平稳过渡型,并能通过以下三种方式在基本鸣唱型的基础上产生鸣唱变异:1)省略、添加或替换鸣唱中的个别音节;2)对鸣唱中的某个部分进行重复或重复不同次数;3)将不同的鸣唱型进行拼接组合.每只个体每种基本鸣唱型至少具有2.0(1-5)个变 异类型,这种变异在个体间和个体内普遍存在.个体间能共享1-2种鸣唱型.所划分的5个组内普遍存在鸣唱型和音节类型的共享,而组间则无鸣唱型共享,有音节类型共享.采用Jaccard相似性系数衡量白头鹎个体间音节的共享情况,发现个体间的音节共享程度在组内 明显大于组间,因此认为越是邻近分布的白头鹎个体具有越相似的鸣唱     

圆蟾舌蛙鸣声特征分析

为研究体型较小的蛙类的鸣声特征,2012年7~8月,采用录音机和指向性话筒,在野外录制51只雄性圆蟾舌蛙(Phrynoglossus martensii)鸣声并对应测量了录音个体的体重、体长及头宽等体征数据。雄性圆蟾舌蛙的体重为(1.26±0.55)g,体长为(21.04±2.57)mm,头宽为(6.76±0.75)mm。该种蛙可发出广告鸣声和争斗鸣声。广告鸣声为单音节鸣叫,主频(3 782.25±167.78)Hz,3 100~4 349 Hz;基频(1 519.69±70.60)Hz,1 057~1 765 Hz。广告鸣声主频和基频均与体重、体长、头宽呈显著负相关,而音节间隔与体重和头宽呈正相关(相关性分析)。争斗鸣声主频(3 752.64±174.47)Hz,(3 304~4 081)Hz;基频(1 674.88±79.88)Hz,1 367~1 870 Hz。与广告鸣声相比,争斗鸣声的基频显著增高(t=﹣5.374,df=56,P0.001),音节时长和音节间隔显著降低(P0.05),而主频在两种鸣声类型中无显著差异(t=0.436,df=56,P=0.665)(独立样本T检验)。结果表明,作为体型较小的蛙类,体型影响了圆蟾舌蛙的鸣声结构和类型。     

云南柳莺鸣声特点及地理差异的初步分析

1997、2002和2005年5～7月,在陕西省、四川省和甘肃省内共7个地区采集云南柳莺(Phylloscopus yunnanensis)的鸣声样本,并分析采自不同地区的共40只个体的鸣声.发现云南柳莺的鸣唱(song)和鸣叫(calls)在同一地区存在一定的差异.比较99段云南柳莺的鸣唱声,发现持续时间与间隔时间之间存在显著的负相关Pearson,r=-0.276,P=0.006,t=99).单因素方差分析表明,不同地区云南柳莺鸣唱的最高频率、最低频率和持续时间没有显著差异,而音节的间隔时间及音素数量均存在显著差异(P=0.006;P=0.000).结果表明,不同海拔、地区之间个体鸣唱音节间隔时间与海拔成正相关(Pearson,r=0.425,P=0.03,n=26).     

红蹼树蛙繁殖期鸣声特征及鸣叫节律

鸣叫是无尾两栖类声音通讯的重要环节之一。许多蛙类的鸣叫行为具有节律性,且受温度和湿度的影响。为研究红蹼树蛙(Rhacophorus rhodopus)的鸣声特征和鸣叫节律,2016年5—6月,采用录音机和指向性话筒,在野外录制了61只雄性红蹼树蛙的鸣声,并通过悬挂录音笔和自动温湿度记录仪研究其鸣叫节律(22 d)。结果发现:红蹼树蛙的鸣声分为单音节和多音节(音节数2~20;平均6.27±2.94)2种类型。与多音节鸣声的主频(2213.32±106.95 Hz)、音节时长(14.83±1.27 ms)和音节间隔(60.66±8.56 ms)相比,单音节鸣声的主频(2289.87±120.14 Hz)、音节时长(16.93±1.68 ms)和音节间隔(610.99±178.48ms)显著升高(P0.05),而2种鸣声的基频(单音节鸣声:212.51±21.63 Hz;多音节鸣声:225.39±26.80 Hz)无显著差异(P0.05)。红蹼树蛙每晚19:00至次日03:00具有鸣叫行为,22:00为高峰期。结果表明:红蹼树蛙主要通过改变鸣声的主频、音节时长、音节间隔以及音节数提高声音通讯效率。红蹼树蛙的鸣叫行为具有昼夜节律,且在一定程度上受温度和湿度的影响。     

叉尾斗鱼繁殖行为的观察

采用室内研究法对叉尾斗鱼(Macropodus opercularis)的繁殖行为进行了观察,结果表明,叉尾斗鱼分批产卵。雌雄鱼交配于21:35~21:55时开始,00:44~1:56时结束,整个过程持续约3~4 h,交配20~37次(Mean=28.83,n=6),时间跨度从8.9~18.6 s(11.31±2.61,n=141);只交配但雌鱼未产卵的伪交配4~6次(Mean=5.17,n=6),时间跨度从6.2~15.5 s(10.27±2.51 s,n=27);只完成交配第一步的伪交配36~117次(Mean=76.83,n=6),时间跨度1.4~15.0 s(5.69±2.31 s,n=440)。生殖期产卵8~9批,每批卵62~1 316粒(Mean=793.36,n=11);孵卵、护幼由雄性担当。卵从产出到孵化成鱼苗离开泡巢历时约4 d。野生叉尾斗鱼6~9月繁殖,产卵期水温22.4~33.5℃,溶解氧量1.1~4.2 mg/L,pH值6.0~7.0。     

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.     

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     

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.     

鸡传染性法氏囊病病毒研究进展

传染性法氏囊病(Infection bursal disease, IBD)是由鸡传染性法氏囊病毒(Infectious bursal disease virus, IBDV)引起的鸡和火鸡的一种高度接触性传染病,给世界各国的禽养殖业带来了巨大损失.自IBDV发现至今新的变异株不断出现,分子结构的改变导致病毒致病力的改变及宿主对疫苗应答的改变,使得传统的疫苗已不能控制其流行,因此各国学者对其基因组结构和功能进行了广泛深入的研究,并积极研制新型有效的疫苗以达到防治的目的.     

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.     

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).