Vinous-throated parrotbills breed in invasive smooth cordgrass habitat:Can native birds avoid the potential ecological trap?

Native animals are facing long-term coexistence with invasive plants worldwide,the impacts of which on animal behavior remain poorly known.Potential ecological traps could threaten native birds breeding in invasive plant habitats,but behavioral strategies for birds to avoid such risks are few concerned.The invasion of Smooth Cordgrass(Spartina alterniflra) has seriously varied the vegetation landscape in the coastal wetlands of eastern China,and affected the habitat selection of native birds.Here,we investigated the nesting and breeding characteristics of a common native passerine,the Vinous-throated Parrotbill(Sinosuthora webbiana),in habitats dominated by native Common Reed(Phragmites australis) and exotic cordgrass.We found that parrotbills could complete their breeding cycle in cordgrass habitat.Most nest failure was attributed to predation in native habitat but tide inundation in cordgrass habitat.However,the nest success rate and daily survival rate(DSR) in cordgrass habitat were higher.Moreover,nest height was markedly higher in cordgrass habitat and was the most important influencing variable(positively correlated with the DSR).These results suggest that cordgrass habitat is a potential ecological trap due to the tide inundation,but some parrotbills seem to effectively avoid this risk by increasing nest height.Our study reveals that a native passerine changes its nesting behavior to accommodate invasive plant habitat and highlights that habitat changes caused by invasive plants may drive the adaptive evolution of native animal behavior.The limitation of these results must be acknowledged for the small sample size,and there is a need for a larger sample and long-term data for further verification.

The Mid-Term Model Forecast Test of North China Rainstorm from July 19th to 20th, 2016

Heavy rain is a kind of severe weather, often causing floods and serious soil erosion, leading to engineering losses, embankment rupture and crop flooding and other significant economic losses. Especially for some low-lying terrain areas, rainwater cannot quickly vent caused by farm water and soil moisture being too saturated, so it will cause more geological disasters. This article combines live and forecast data, aiming at the results of the mid-rainstorm forecast in North China during the period of 7.19-2016, and compares with the actual situation of rainstorm. We carry out the mid-term forecast of the rainstorm. The atmosphere is a kind of medium with various fluctuation phenomena, and its physical properties and changes are studied by the analysis of volatility which is an important research method. It is important to improve the accuracy of such severe weather forecasting rainstorms and to take precautionary measures in a timely manner to minimize the losses caused by rainstorms.

Phosphorylation of PB2 at serine 181 restricts viral replication and virulence of the highly pathogenic H5N1 avian influenza virus in mice

Influenza A virus(IAV)continues to pose a pandemic threat to public health,resulting a high mortality rate annually and during pandemic years.Posttranslational modification of viral protein plays a substantial role in regulating IAV infection.Here,based on immunoprecipitation(IP)-based mass spectrometry(MS)and purified virus-coupled MS,a total of 89 phosphorylation sites distributed among 10 encoded viral proteins of IAV were identified,including 60 novel phosphorylation sites.Additionally,for the first time,we provide evidence that PB2 can also be acetylated at site K187.Notably,the PB2 S181 phosphorylation site was consistently identified in both IP-based MS and purified virus-based MS.Both S181 and K187 are exposed on the surface of the PB2 protein and are highly conserved in various IAV strains,suggesting their fundamental importance in the IAV life cycle.Bioinformatic analysis results demonstrated that S181E/A and K187Q/R mimic mutations do not significantly alter the PB2 protein structure.While continuous phosphorylation mimicked by the PB2 S181E mutation substantially decreases viral fitness in mice,PB2 K187Q mimetic acetylation slightly enhances viral virulence in mice.Mechanistically,PB2 S181E substantially impairs viral polymerase activity and viral replication,remarkably dampens protein stability and nuclear accumulation of PB2,and significantly weakens IAV-induced inflammatory responses.Therefore,our study further enriches the database of phosphorylation and acetylation sites of influenza viral proteins,laying a foundation for subsequent mechanistic studies.Meanwhile,the unraveled antiviral effect of PB2 S181E mimetic phosphorylation may provide a new target for the subsequent study of antiviral drugs.

Behaviors of Leucine and Isoleucine in Ion Mobility- Quadrupole Time of Flight Mass Spectrometry

In this study, ion mobility separation coupled with tandem mass spectrometry （IM-tandem MS） was utilized to investigate the ionization behaviors of two amino acids including leucine and isoleucine. Under the electrospray ionization （ESI） mode, two protonation sites in each molecular sturcture caused two forms of protomer. One arose from the amino being protonated （amino-protomer） and the other from the carboxyl being protonated （car- boxyl-protomer）. In the two-dimensional （drift time, m/z） spectrum, the protomers had the same mass, but the dis- tinguishable drift times and fragmentation patterns. For the characterization purpose, the theoretical collision cross section （CCS） values of the protomers were calculated and proven to be consistent with the experimental. Moreover, the quantified relationship between the amino acids and their protomers was evaluated. It showed that the abun- dance of the carboxyl-protomer was proportional to the concentration of the amino acid, whereas that of the amino- protomer did not have the same trend. Under the atmospheric pressure chemical ionization （APCI） mode, only the carboxyl-protomer was observed. In addition, the amino-protomer and the cluster ions observed under ESI were absent completely. The results demonstrate that the ionization mode impacts heavily on the ionization behaviors of leucine and isoleucine not only on the form of therir protomers but also On the quantified relationship.

通向更精确的因果分析:交叉滞后模型的新进展

近年来,变量间因果关系越来越受到学者们的关注。基于纵向面板数据的交叉滞后模型,能够帮助研究者精准掌握变量间相互影响的机制,从而建立初步的因果关系。但由于缺乏系统的梳理与实操指导,近几年提出的前沿交叉滞后模型未能被人力资源领域的研究者广泛应用。为弥补这一缺憾,本文对交叉滞后模型的最新进展进行梳理。首先,本文回顾应用较广的传统交叉滞后模型及其主要成分。其次,本文细致地介绍了两个进阶版的交叉滞后模型:带随机截距的交叉滞后模型和广义交叉滞后模型。再次,本文系统梳理和对比这些模型的优缺点、建模过程中的注意事项,并用真实数据进行分析和对比。最后,本文对交叉滞后模型在实证研究中的应用提供参考依据和实操建议。

Song variation of a native songbird in a modified habitat by invasive plant

Habitat structure has been considered as an important factor affecting the acoustic evolution of birds,and bird songs are increasingly affected by artificial environmental variation.Invasive plants sometimes can dramatically alter native habitats,but the song variation of native songbirds migrating into invaded habitats has received little attention.The invasion of smooth cordgrass Spartina alterniflora in the coastal wetlands of eastern China has drastically altered the vegetation structure and some small passerines have begun to use invaded habitats to breed.In this study,we compared the song type prevalence and the song characteristics of male plain prinia Prinia inornata to identify differences in vocal behavior between native and invaded habitats.We also tested for differences in vocal behavior in relation to singing perch and wind speed variation between different habitats.The results indicated that males of plain prinia in invaded habitats sang shorter songs than those in native habitats and had a lower song diversity.The homogeneous vegetation structure and higher wind speed in invaded habitats likely leads to males changing the traditional perched singing style.The song variation may be related to the founder effect,the alteration of vegetation structure and microclimate in invaded habitats.This finding highlights the need for better understanding the behavioral evolution of native species in the process of adapting to the invaded habitat.In the future,experimental manipulation is needed to ascertain how the invasive plant drove these vocal behavior changes of native songbirds.