草蛉科纳草蛉属研究（Ⅱ）—六新种记述（脉翅目：草蛉科）

本文是纳草蛉属Navasius研究续报(研究Ⅰ见“动物分类学报”第15卷第3期)。报道了纳草蛉属6新种:跃纳草蛉N.igneus sp.nov.,冠纳草蛉N.lophophorus sp.nov.,黑角纳草蛉N.nigricornutus sp.nov.显沟纳草蛉N.phantosulcus sp.nov.康纳草蛉N.sanus sp.nov.及三齿纳草蛉N.tridentatus sp.nov.。     

云南省粉蛉两新种记述（脉翅目：粉蛉科）

记述云南省脉翅目粉岭科2新种：奇斑曲粉岭Coniocom psa spectabilis Liu et yang,sp.nov和丫重粉蛉Semidalis ypsilon Liu et Yang,sp.nov。。模式标本均保存在中国农业大学昆虫标本馆。     

俗草蛉属的研究及三新种记述(脉翅目:草蛉科)

本文报道了发现于我国的俗草蛉属Suarius 3新种:海南俗草蛉S.hainanus sp.nov.,钩俗草蛉S.hamulasus sp.nov.及楔唇俗草蛉S.sphenochilus sp.nov.新种模式标本保存于北京农业大学昆虫标本室。     

中国树蚁蛉属分类研究(脉翅目,蚁蛉科)

记述了中国蚁蛉科树蚁蛉属Dendroleon 5种,其中包括3新种:丽翅树蚁蛉Dendroleon callipterum Wan et Yang,sp.nov.,李氏树蚁蛉Dendroleon lii Wan et Wang,sp.nov.,珠斑树蚁蛉Dendroleon perlistigma Wan et Wang,sp.nov..模式标本保存在中国农业大学昆虫标本馆.     

草蛉科一新属——纳草蛉属研究(Ⅰ)(脉翅目:草蛉科)

本文对草蛉科(Chsysopidae)玛草蛉属Mallada做了修正,并建立一新属——纳草蛉属Navasius gen. nov. 同时报道了纳草蛉属6新种:槽纳草蛉N. alviolatus sp. nov. 钩纳草蛉N. ancistroideus sp. nov. 无斑纳草蛉N. epunctatus sp. nov. 曲纳草蛉N. flexuosus sp. nov. 海南纳草蛉N. hainanus sp. nov. 及和纳草蛉N. hesperus sp. nov.。     

中国意草蛉属二新种(脉翅目,草蛉科,草蛉亚科)

记述了中国意草蛉属2新种:晕翅意草蛉Italochrysa psaroala sp.nov.和黄意草蛉Italochrysa xanthosoma sp.nov.。新种模式标本保存于中国科学院动物研究所动物标本馆(IZCAS)和中国农业大学昆虫标本馆(CAU)。     

辽宁北票晚侏罗世丽蛉化石二新属(脉翅目,丽蛉科)

描述丽蛉科化石2新属2新种：美形山丽蛉oregramma gloriosa gen.et sp.nov.,奇异沼泽丽蛉Limnogramma mira gen.et sp.nov.。标本采自辽宁省北票市晚侏罗世义县组地层中。模式标本保存在首都师范大学生物系。     

河南省蝶角蛉一新种(脉翅目:蝶角蛉科)

记述了蝶角蛉科原完眼蝶角蛉属1新种：狭翅完眼蝶角蛉Protidricerus steropterus sp.nov.,标本采用河南省嵩山县白云山,模式标本保存在中国农业大学昆虫标本室。     

内蒙古自治区中侏罗世表翼蛉化石一新种(脉翅目:翼蛉科)

描述表翼蛉属化石1新种,潘氏表翼蛉Epiosmylus panfilovi sp.nov。讨论了表翼蛉属的科级分类问题。标本采用内蒙古自治区宁城县山头乡中侏罗世地层中。     

山西省草蛉一新种(脉翅目:草蛉科)

作者在对本所馆藏草蛉标本进行整理鉴定中,发现一新种。属草蛉科(Chrysopidae)纳革蛉属(Navasius Yang et Yang),因新种采自山西省盂县境内,故定名为盂县纳草蛉(Navasius yuxianensis sp.nov.)。模式标本保存在山西省农业科学院植物保护研究所标本室。     

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.