中国寄蝇科狭颊寄蝇属研究(双翅目:寄蝇科)

综合研究中国狭颊寄蝇属73种的鉴别方法、分布、寄主种类;研究并发现一些种类的变异特点,♀、♂异型等现象;文中附有73种的检索表及特征图,15个新种的描述;订正了5种为新异名.重建了狭颊寄蝇属的分类系统.     

中国寄蝇科狭颊寄蝇属研究

综合研究中国狭颊寄蝇属73种的鉴别方法、分布、寄主种类;研究并发现一些种类的变异特点,♀、♂异型等现象;文中附有73种的检索表及特征图,15个新种的描述;订正了5种为新异名。重建了狭颊寄蝇属的分类系统。     

中国寄蝇二新种(双翅目:寄蝇科)

本文记述采自北京和云南的寄蝇二新种。新种模式标本保存于中国科学院动物研究所。 黑棒鞘寄蝇 Thecocarcalia melanohalterata, 新种(图1—5) 头、胸、腹全部黑色。侧额及胸部背面覆黄褐色粉被,其余部分覆灰色粉被;沿腹部背中线具一狭窄的黑纵条,粉被在腹部占第3背板基部的1/5,第4,5背板的1/2—3/5;上下腋瓣,平衡棒基半部、爪垫、唇瓣及雌蝇下颚须端半部黄褐色,平衡棒端半部黑褐色,翅灰色透明。     

中国寄蝇科的记述黄角寄蝇属新属

在整理研究埃内寄蝇族Ernestiini标本的过程中,发现一个新属,即黄角寄蝇属Flavicorniculum新属,分布于我国浙江、四川、广西、云南诸省。共包括四个新种,现记述于后。 所有模式标本均保存于中国科学院动物研究所。     

中国寄蝇科的记述Ⅵ.蜉寄蝇属

蜉寄蝇属Phorocera R.-D.,1830年,目前在世界范围内共包括4种,是寄蝇亚科中一个较小的属;根据我国现有标本已发现7种,其中有3个新种。本属的种类均为大卵型寄蝇,多寄生于鳞翅目害虫,特别是Ph.agilis R.-D.(=silvestris R.-D.)为舞毒蛾的重     

中国寄蝇科的记述Ⅷ.刺蛾寄蝇属

刺蛾寄蝇属Chaetexorista B.B.1894目前在世界范围内已记载有4种,即Ch.javanaB.B.1894,Ch.eutachinoides Bar.1932,Ch.solomonensis Bar.1936和Ch.klapperichiMesnil 1960;在我国,现共发现6种,其中有3个是新种,另有1种为我国初次记录。 本属寄蝇的寄主,文献中尚无记载,通过野外采集和室内饲养,我们得知,这一属的寄蝇是刺蛾科幼虫的重要天敌。 本文以记述新种为主,其余3种的主要特征仅在检索表内加以说明;对于它们的生物学特性和寄主种类,将在经济昆虫志内做详细介绍。新种的模式标本均保存于中国科学院动物研究所。     

中国金绿寄蝇属记述：双翅目：寄蝇科

金绿寄蝇属Chrysocosmius在全世界已记载5种(古北界3种,东洋界2种),本文报道我国7种,其中包括4新种和2中国新纪录。新种为:巨眼鬃金绿寄蝇Chrysocosrmius ocellosetus,单鬃金绿寄蝇Chr.monostus,双齿金绿寄蝇Chr.bidentatus,亚合眼金绿寄蝇Chr.euholopticus。本文还编有种检索表。     

中国寄蝇科的记述Ⅸ.豪寄蝇属Hystriomyia

豪寄蝇属Hystriomyia Portschinsky建立于1882年,至今记载的仅有3种;在我国又发现两个新种。本文以记述新种为主,为了便于识别,将其余3种的主要特征列入检索表中,并附图加以说明。新种的模式标本均保存于中国科学院北京动物研究所。 种检索表 1(2)体表的鬃与毛全部黑色:头部具外侧额鬃,肛尾叶长三角形,末端具1小齿(图Ⅰ):缝后翅内鬃3;第5腹板     

中国瑟寄蝇属种类纪要（双翅目：寄蝇科）

研究了我国蜗寄蝇族瑟寄蝇属Cyrtophleba(双翅目:寄蝇科)2种,其中茹瑟寄蝇Cyrtophleba ruricola 分布于辽宁,山西,宁夏,新疆;变瑟寄蝇Cyrtophleba vernalis为中国新记录种,分布于辽宁。给出了上述2种的鉴别特征及变瑟寄蝇头和雄性尾器的特征图。研究标本分别保存于沈阳师范大学昆虫标本室(SYNU),中国科学院动物研究所(IZCAS)和国家林业局森林病虫害防治总站(GSFPM)。     

中国利索寄蝇属的研究(双翅目:寄蝇科)

利索寄蝇属Lixophaga Townsend,1908隶于寄蝇科Tackinldae,卷蛾寄蝇族Blondeliinio该属大部分种类分布于新北界,古北界已描述的种类有3种,而且都采自日本,东洋界尚无记载。1964年,中国从古巴引进螟利索寄蝇L. diatmeae(Townsend),多年饲养未获成功。本文记述中国利索寄蝇属3种,其中一新种和二新纪录;为了便于比较和鉴定,把掌握有标本的另外两个种,即L.diatraeae(Townsend)和L. fallax Mesnil均     

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.     

Selection with two alleles and complete dominance

For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.     

Composition and diversity of bird communities in Swedish farmland–forest mosaic landscapes

CapsuleThe amount of forest (at local and landscape scales) and occurrence of residual habitats at the local scale are shown to be the major factors influencing bird community composition in farmland–forest landscapes in central Sweden.

Aims To investigate the importance of local habitat and landscape structure for breeding birds in farmland–forest landscapes in central Sweden.

Methods Breeding birds were censused at 292 points. A detailed habitat mapping was made within 300 m of the points. Within a 300–600 m radius only two major habitats (forests and arable fields) were identified.

Results Cluster analyses of bird communities identified three site types that also differed in habitat composition: (i) partially forested sites in forested landscapes; (ii) heterogeneous sites with residual habitats in mosaic landscapes; and (iii) field-dominated farmland sites in open landscapes. A total of 19 of 25 farmland bird species (restricted to farmland or using both farmland and forest) had the highest abundance in farmland sites with mosaics of forest and farmland, while only six farmland species had the highest abundance in field-dominated sites. The bird community changed from being dominated by farmland species to being dominated by forest species (common in forest landscapes without farmland) at small proportions (10–20%) of forest at the local scale. A major difference in habitat composition between heterogeneous and field-dominated sites was the occurrence of different residual habitats (e.g. shrubby areas and seminatural grasslands). These habitats seemed to influence bird community composition more than land-use, despite covering <10% of the area. Seminatural grasslands were important for bird community composition and species-richness, but grazing seemed to be less important. Among different land-use types, cereal crops were the least preferred fields. Set-asides with tall vegetation and short rotation coppices were positively associated with species-richness of farmland birds.

Conclusion In general, the composition of the landscape was important for bird community composition, although amount and distribution of forests, occurrence of residual habitats and land-use of fields at the local scale had the strongest influence on bird community composition. The possible implications of these patterns for managing farmland–forest landscapes are discussed.     

Chemical constituents from the fruits of Rhus typhina L. and their chemotaxonomic significance

This work describes the isolation and characterization of twenty-nine compounds from the fruits of Rhus typhina L., including eleven flavonoids (1–11), eleven phenols (12–22), two pentacyclic triterpenes (23–24), two organic acids (25–26), one lumichrome (27), one courmarin (28) and one pyrimidine (29) on the basis of their spectroscopic data. Compounds apigenin (1), daidzein (4), orobol (5), 3′, 5, 5′, 7-tetrahydroxyflavanone (6), naringenin (7), butein (8), (-)-catechin (9), quercetin-3-O-α-L-(3″-O-galloyl)-rhamnoside (11), 2-hydroxybenzoic acid (13), 4-hydroxybenzaldehyde (14), vanillin (15), methyl 3,4-dihydroxybenzoate (16), 3,5-dihydroxybenzamide (18), tyrosol (19), caffeic acid (20), 3-(2,4,6-trihydroxyphenyl)-1-(4-hydroxyphenyl)-propan-1-one (21), phlorizin (22), friedelin (23), oleanolic acid (24), 4,4-dimethyl-heptanedioic acid (25), anthranilic acid (26), lumichrome (27), scoparone (28) and uracil (29) have not been recorded before in this plant. This is the first report on the occurrence of compounds 4–7, 9, 11, 13–14, 16, 18–21, 25–29 from the genus Rhus. Moreover, the chemotaxonomic significance of these isolated compounds was also summarized.