在中国应用垂直波束雷达监测褐飞虱和其他水稻害虫迁飞的可行性

近年来,可用于昆虫迁飞研究且可自动运行的垂直波束雷达(vertical-looking radar,VLR)的发展使得对迁飞性害虫的周年长期自动监测成为可能。本文提供了我们对能否将这种雷达应用于中国的褐飞虱和其他水稻害虫的监测与预测体系以改善其综合治理的可行性研究结果。以往的研究已经表明,这些害虫一般在300—2000m高度迁飞;而我们根据褐飞虱的雷达和射有效截面的计算结果表明,目前使用的3．2cm波长的VLR对褐飞虱个体目标的最大可检测高度仅约240m;虽然建造一部8．8mm波长的VLR即可覆盖褐飞虱迁飞高度的绝大部分,但其造价和维护费用均过于昂贵。为此,一个更可行的解决方案是,以3．2cm波长的VLR作为包括大多数水稻害虫在内的个体较大的迁飞性害虫的监测工具。     

昆虫迁飞行为的参数化

通过对雷达昆虫学研究和其他方法得到的研究成果的综合分析,提出一套昆虫迁飞行为参数化方案。即：起飞时间以日出日 晨昏朦影时 基准,降落时间依目标昆虫的迁飞牧场考具体取值;运行高度取边界层顶与目标昆虫飞行低温阈限所在高度之间的气流层。在运行方向取风向值并以目标昆虫的定中以修饰,运行速度与目标昆虫自身行速度的矢量和。这套方案可作为昆虫迁飞数值模拟的基础,为迁飞性害虫异地预测提供一种有效的工具 。     

迁飞昆虫生物学参数反演及种类辨识分析

虫害严重威胁着我国的粮食安全,迁飞昆虫中有许多是农业害虫,其远距离迁飞是导致虫害异地暴发的重要原因.昆虫雷达是观测昆虫迁飞最有效的工具,在迁飞昆虫的监测和预警中发挥着越来越重要的作用,但传统昆虫雷达不能准确获取昆虫的各项生物学参数,因此无法实现昆虫种类的精确识别.随着雷达技术的创新和发展,通过昆虫雷达获得较为准确的昆虫生物学参数成为可能,为基于昆虫雷达实现迁飞昆虫个体种类辨识提供了依据.本文综述了从雷达回波中提取多频和极化散射参量,然后基于不同的电磁散射反演昆虫生物学参数的方法,并对比分析了基于不同方法的昆虫体重、体长、体宽和振翅频率的反演精度.最后基于生物学参数,采用5种机器学习算法以高精度实现了 23种迁飞昆虫的种类辨识,并分析了昆虫生物学参数的测量误差对迁飞昆虫种类辨识精度的影响,初步验证了利用雷达实现高精度迁飞昆虫种类辨识的可行性.     

昆虫迁飞行为的参数化Ⅰ.行为分析

通过对雷达昆虫学研究和其他方法得到的研究成果的综合分析,提出一套昆虫迁飞行为参数化方案。即：起飞时间以日出日没及晨昏朦影时刻为基准,降落时间依目标昆虫的迁飞特性具体取值;运行高度取边界层顶与目标昆虫飞行低温阈限所在高度之间的气流层,运行方向取风向值并以目标昆虫的定向加以修饰,运行速度为风速与目标昆虫自身飞行速度的矢量和。这套方案可作为昆虫迁飞轨迹数值模拟的基础,为迁飞性害虫异地预测提供一种有效的工具     

垂直监测昆虫雷达研究进展

昆虫雷达可以远距离、 大范围、 快速地探测迁飞昆虫, 这极大促进了人类对昆虫迁飞行为的认识。垂直监测昆虫雷达技术是从20世纪70年代发展起来的一种监测高空迁飞昆虫种群的新工具。与传统的扫描雷达相比, 垂直监测昆虫雷达可以获得目标的位移速度、 位移方向、 定向、 体型大小和形状等参数, 因此, 对目标的识别能力更为精确。此外, 垂直监测昆虫雷达实现了在微机控制下的自动运行, 这使得应用昆虫雷达开展迁飞昆虫的日常监测成为可能。本文综述了垂直监测昆虫雷达的发展和应用, 介绍了设计原理和回波参数的解算方法, 讨论了其存在的不足及改进方案, 最后并对其在未来昆虫雷达网络建设中的应用进行了展望。     

北京多普勒天气雷达上的昆虫回波分析

【目的】为了解北京多普勒天气雷达上的昆虫回波信息,探索其在迁飞害虫监测预警中的应用。【方法】选取北京南郊观象台新一代天气雷达CINRAD-SA积累的晴空回波数据和风廓线雷达提供的风速风向数据,基于有关软件分析了昆虫回波的特点,讨论了降水等其他因素对昆虫迁飞的影响。【结果】新一代天气雷达可以探测到空中迁飞昆虫引发的后向散射回波,晴空回波日节律符合夜行性昆虫的朦影起飞和日出降落的行为特点,晴空回波出现的时期是3月至11月,中间有2个高峰期;晴空回波数量与风向关系密切,当天气系统合适时,晴空回波会出现成层和共同定向现象;此外,降水会中断昆虫迁飞。【结论】北京多普勒天气雷达可以探测昆虫迁飞,在迁飞性害虫监测预警及其综合防控工作中具有重大的潜在应用价值,今后农业部门在优先建立昆虫雷达网络的同时,应加强与气象部门合作,发挥天气雷达的补充作用,共同提高迁飞性害虫的监测预警水平。     

昆虫雷达建制技术的发展方向

昆虫雷达是开展迁飞害虫监测与研究的一种重要手段,中国也是较早自主建设与应用昆虫雷达的国家之一。为促进我国昆虫雷达事业的发展,本文对扫描昆虫雷达和垂直监测昆虫雷达的体制和特点进行了总结,介绍了今后昆虫雷达建制技术的发展方向及有关的初步实践与应用。     

追踪天使——雷达昆虫学30年

雷达昆虫学是一门新的学科分支。从它诞生起的30年来,英、美、澳、中四国的观测研究已初步阐明了昆虫在迁飞过程中的成层、定向、集聚等行为现象及其时空分布,揭示了大气结构和运动对昆虫迁飞的影响,为深化人们对昆虫迁飞行为机制的认识提供了许多令人耳目一新的画面;昆虫雷达技术也逐渐从研究走向实用,已经实现了对迁飞性害虫的长期、自动和实时监测。在全国建立VLR网并与GIS相结合,可望实现对我国重大虫灾的及时预警。     

华北二点委夜蛾种群动态监测及北京北部地区虫源性质分析

二点委夜蛾Proxenus lepigone是玉米生产中的一种新发害虫, 2011年曾在黄淮海夏玉米主产区全面暴发, 对夏玉米生产构成严重威胁。为了明确二点委夜蛾的种群动态, 探讨北京北部二点委夜蛾种群是否为迁入虫源, 2012年, 在华北地区的河北省栾城县、 北京市区和北京延庆县等地, 利用高空探照灯诱虫器、 垂直监测昆虫雷达等对二点委夜蛾成虫进行了监测, 并结合气象资料, 对北京延庆的虫源性质进行了综合分析。结果表明： 二点委夜蛾老熟幼虫作茧后可在北京延庆越冬。2012年, 北京延庆诱集二点委夜蛾累计33 951头, 可划分为3个世代。第1代成虫的诱集数量不符合正态分布, 且在姊妹灯下的数量差异符合迁飞种类的特点。在当地条件不适宜的情况下, 北京延庆监测点第1代成虫日均诱虫数量高于条件相对适宜的河北栾城。在北京延庆, 第1代成虫的逐日诱集数量与空中风向密切相关。雷达监测还表明二点委夜蛾可能是雷达回波的目标。综合以上证据表明, 北京延庆第1代成虫包含从周边迁飞而来的个体, 二点委夜蛾可能是一种兼性迁飞昆虫。本研究可为二点委夜蛾成虫能否远距离迁飞提供例证, 对今后提高其预测预报和防治水平具有重要意义。     

南岭稻区褐稻虱、白背飞虱数量预测研究

<正> 褐稻虱、白背飞虱是南岭稻区主要害虫。两种飞虱均属迁飞性害虫,为害虫源来自外地迁入。有关它们的数量预测国内未见报道,为此,南岭稻区迁飞性害虫科研协作组近年来开展了这一课题研究,试图为生产应用提供科学依据。现将研究结果总结如下:     

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.