棕色固氮菌细菌铁蛋白释放铁的动力学方程和性质

棕色固氮菌细菌铁蛋白铁核中的磷铁组成存在非均匀性。细菌铁蛋白释放铁的动力学特性表现出复杂性。通过动力学曲线分析，提出蛋白壳自身调节能力起着限制释放铁速率关键步骤的观点，建立分析铁蛋白释放铁的动力学特性方程并用它较合理地阐明铁蛋白释放铁的动力学规律及储存铁的途径。用分光光度法和动力学方程研究细菌铁蛋白释放铁的全过程，其结果表明该蛋白以一级反应方式释放铁核表层的铁和以零级反应方式释放铁核内层的铁。外加磷酸盐能强烈地抑制释放铁的速率，引起释放铁的反应级数的转化，迫使铁蛋白以一级反应的方式释放铁核中的大多数铁。国家教委回国留学人员基金;福建省自然科学基

Damage to mangroves from extreme cold in early 2008 in southern China

通讯作者Author for correspondence (E-mail: [email protected])2008年初,我国南方19个省经历了50年一遇的持续低温雨雪冰冻天气。极端气候对华南沿海各省的红树林区造成不同程度的危害。2008年3月,在我国南方各省红树林区的10个代表性地点,对这次寒害造成的红树植物伤害程度进行了系统的调查。结果表明:冬季低温对红树林的影响极为显著,特别是在低纬度的海南、广西和广东湛江,由于极端低温正值夜间退潮,对红树林的影响更为显著;在纬度较高的福建,本地红树种类秋茄(Kandelia obovata)、桐花树(Aegiceras corniculatum)和白骨壤(Avicennia marina)及引种的木榄(Bruguiera gymnorrhiza)等,由于长期适应于冬季较低的气温或在种植前经过抗寒锻炼,具有较强的抗寒能力。各地主要红树植物中,广布种秋茄、桐花树和白骨壤最为耐寒,其耐寒性均大于红树科的木榄、海莲(Bruguiera sexangula)和红海榄(Rhizophora stylosa)。海桑(Sonneratia caseolaris)对温度的敏感性最强,抗寒能力最低,因此,即使在其原产地海南也受到较为严重的寒害,在纬度更高的引种地出现大面积受害甚至全部死亡,而从孟加拉国引种的无瓣海桑(Sonneratia apetala)却显示出一定的抗寒能力。同一地点的红树植物幼苗的抗寒能力低于大树。此次寒害也造成了苗圃场的种苗大量死亡,成熟的植株提前落花落果,这势必会影响后继一两年内红树林的自然更新和人工造林。因此,在未来红树林造林或人工引种中,一定要考虑到红树植物的抗寒能力。国家自然科学基金(30671646和30700092);厦门大学“闽江学者”启动基

Progress in the study of the selective feeding of heterotrophic nanoflagellate

微型异养鞭毛虫(Hnf)是海洋微微型浮游生物的重要摄食者,通过摄食作用对后者的种类(或类群)组成、粒径分布、数量结构和营养价值等属性具有重要的影响,而这与Hnf的摄食选择性有直接关系。对Hnf摄食选择性的研究有助于深入了解Hnf在海洋微食物环乃至整个海洋生态系统中的作用。就国际上已开展的Hnf摄食选择性相关研究进行了回顾,分析和总结了影响Hnf选择性摄食的关键因素,如食物大小、游动性、营养价值及食物细胞表面的生化结构特征等,并重点介绍了Hnf摄食选择性形成的主要机制以及Hnf的选择性摄食在调节海洋微微型浮游生物群落结构中的作用。Heterotrophic nanoflagellate(abbr.,HNF) is the principal consumer of picoplankton in marine ecosystem.Recognizing its selective feeding impact is essential to evaluate the role of HNF in the marine microbial food web.Over the last few decades,there has been a concerted effort by many researchers to the understanding of selective grazing behaviors among HNF.This paper,(1) summarize current knowledge on factors affecting HNF selective feeding;(2) discuss mechanisms involved in HNF selective feeding;(3) review the influence of HNF selective feeding on the shape,size structure,taxonomic composition and physiological status of picoplankton communities.国家973计划项目课题(No.2011CB409804); 国家自然科学基金项目(No.40876078

Morphological and Molecular Identification of a Marine Flagellate

采用微液滴操作法在厦门海域分离培养了一株海洋鞭毛虫C6,运用显微镜观察和18SrdnA基因技术鉴定其种类,并将其与gEnbAnk中已知的14种海洋鞭毛虫18SrdnA序列比较,用nJ法和uPgMA法构建系统发育树.通过PCr扩增获得1 774bP 18SrdnA序列,与nCbI已登陆的其他同源序列进行系统分析,结果显示此海洋鞭毛虫属于领鞭毛虫(CHOAnOflAgEllATES).与已知种MOnOSIgA brEVICOllIS的相似性为99%,为进一步研究该种鞭毛虫提供了遗传背景,但要明确其种类还需其他研究佐证.Using microscope and 18 SrDNA techniques,a strain of nanoflagellate(C6)separated in Xiamen Bay was identified and analyzed.One 1 774 bp fragment of 18 SrDNA was amplified from the strain C6.Homology analysis between the yielded sequence and the 18 SrDNA sequences accessed in the National Center for Biotechnology Information(NCBI)from other strains showed that C6 belonged to choanoflagellates,which shared 99% homologue with the known species of Monosiga brevicollis.Choanoflagellates play a very important role in biological evolution and marine ecology,however,molecular phylogenetic studies within choanoflagellates are still extremely limited.According to results of morphological and DNA sequence analysis,we consider that C6 should be Monosiga brevicollis,but more collaborations are still required for specific identification.This study provides basic genetic information for further study of physiological characteristics and ecological functions of the strain C6 in Xiamen Bay.国家自然科学基金(41376131); 国家重点基础研究发展计划(973计划)(2011CB409804

John Fryer and The Translator’s Vade-mecum: the identification of the “Vocabulary of Terms in Naval Architecture"

John Fryer was one of the most important foreign translators in China after the Opium Wars. The work that is the final result of his experience at the Jiangnan Arsenal is The Translator’s Vade-mecum. Among the preparatory manuscripts of the glossaries that were published in the Vade-mecum, the author has identified the “Vocabulary of Terms in Naval Architecture.” The purpose of this article is to examine the main features of the Vocabulary, its sources and the peculiarities of the manuscript. In the first and second sections, the Vade-mecum is concisely analysed; providing numerous references and simultaneously sketching an outlook of the production and circulation of knowledge in the period considered, the author presents theoretical discussions concerning the norms of translation applied in the Vade-mecum, its purpose and the patronage of the translation activity. In the third and main section, studying the historical significance and linguistic quality of some of the translated terms annotated in the “Vocabulary,” the author compares its terminology with the concurrent Japanese one and with other Chinese relevant nomenclatures, demonstrating the complicate interaction in the “Vocabulary” between lexical innovation and recovery of existing terms

Measurement of integrated luminosity of data collected at 3.773 GeV by BESIII from 2021 to 2024

We present a measurement of the integrated luminosity e+e- of collision data collected by the BESIII detector at the BEPCII collider at a center-of-mass energy of Ecm = 3.773 GeV. The integrated luminosities of the datasets taken from December 2021 to June 2022, from November 2022 to June 2023, and from October 2023 to February 2024 were determined to be 4.995±0.019 fb-1, 8.157±0.031 fb-1, and 4.191±0.016 fb-1, respectively, by analyzing large angle Bhabha scattering events. The uncertainties are dominated by systematic effects, and the statistical uncertainties are negligible. Our results provide essential input for future analyses and precision measurements