黑眶蟾蜍的两性异形与选型配对模式

本研究以黑眶蟾蜍(Duttaphrynus melanostictus)为研究对象,通过对比黑眶蟾蜍抱对个体的体长、头长、头宽、眼间距、鼓膜径、耳后腺长、眼径、前臂及手长、前肢长以及后肢长等形态特征,分析雌性黑眶蟾蜍繁殖输出与其体型的关系,探究黑眶蟾蜍两性异形模式及其与雌性生育力的关系;同时通过对配对个体形态学特征的相关性分析探究了黑眶蟾蜍的配对模式。结果表明,黑眶蟾蜍雌性体长和体重显著大于雄体;两性的所有局部形态特征均与体长成正相关;去除体长因素影响后,雄性头长以及后肢长均明显大于雌性,其余局部形态特征两性间则皆无显著差异。雌体的窝卵重、窝卵数均与其体长和体重成正相关关系。雌性成体的前肢长与抱对雄性成体的前肢长之间呈显著正相关,其余形态特征两性间均无相关性。研究表明,生育力选择是导致黑眶蟾蜍两性异形的重要驱动力;黑眶蟾蜍的选型配对模式未表现在个体大小上,而是体现在局部特征(前肢长),这不仅为揭示两栖类配对模式的普遍性提供了参考,还表明对两栖类选型配对的研究应以多个性状为对象。     

柴河林区小型啮齿动物群落格局变化

为阐明柴河林区小型啮齿动物群落结构与格局的形成原因,掌握林区啮齿动物群落动态及发展趋势。于2012至2015年在柴河林区的新房子、大青沟和二道河子地区,对针阔混交林、阔叶林、草甸、沿河林和农田5种生境类型,采用铗日法对小型啮齿动物进行了调查。结果表明,棕背?（Clethrionomys rufocanus）和大林姬鼠（Apodemus peninsulae）为柴河林区小型啮齿动物的优势物种,针阔混交林为棕背?最适生境,阔叶林为大林姬鼠最适生境;黑线姬鼠（A. agrarius）和大仓鼠（Cricetulus triton）为农田优势物种,东方田鼠（Microtus fortis）仅在草甸中发现。随生境垂直分布区海拔高度的降低,总捕获率逐渐减低,其中棕背?的种群变化起主要作用;大林姬鼠的捕获率逐渐增加,其对农业经济的干扰适应性更强;褐家鼠（Rattus norvegicus）的分布规律受居民点分布比例影响;红背?（Clethrionomys rutilus）主要分布于海拔相对较高的针阔混交林。通过与孙儒泳等20世纪60年代在此地区的研究结果的比较,最后认为近几十年原始森林的破坏,伴生的次生林和人工林,致柴河林区的针阔混交林向阔叶林的过渡失去先前的典型特征。并发现小型啮齿动物的群落格局变化,虽呈现出自然条件的垂直变化和农业活动影响的规律,但同时存在生境变化的适应性改变,也表现出各地区的区域生境特征对取样点微生境啮齿动物分布的巨大影响。     

The Arabidopsis CrRLK1L protein kinases BUPS1 and BUPS2 are required for normal growth of pollen tubes in the pistil

In flowering plants, the interaction of pollen tubes with female tissues is important for the accomplishment of double fertilization. Little information is known about the mechanisms that underlie signalling between pollen tubes and female tissues. In this study, two Arabidopsis pollen tube‐expressed CrRLK1L protein kinases, Buddha's Paper Seal 1 (BUPS1) and BUPS2, were identified as being required for normal tip growth of pollen tubes in the pistil. They are expressed prolifically in pollen and pollen tubes and are localized on the plasma membrane of the pollen tube tip region. Mutations in BUPS1 drastically reduced seed set. Most of the bups1 mutant pollen tubes growing in the pistil exhibited a swollen pollen tube tip, leading to failure of fertilization. The bups2 pollen tubes had a slightly abnormal morphology but could still accomplish double fertilization. The bups1 bups2 double mutant exhibited a slightly enhanced phenotype compared to the single bups1 mutants. The BUPS1 proteins could form homomers and heteromers with BUPS2, whereas BUPS2 could only form heteromers with BUPS1. The BUPS proteins could interact with the Arabidopsis pollen‐expressed RopGEFs in the yeast two‐hybrid (Y2H) and bimolecular fluorescence complementation (BiFC) assays. The results indicated that the BUPSs may mediate normal polar growth of pollen tubes in the pistil.     

建筑与庭院“共舞”—以清华大学八家附小建筑设计为例

建筑和庭院的关系一直以来是建筑学重要的研究课题之一。以清华大学八家附小建筑与庭院设计为例进行研究,提出建筑与庭院“共舞”的理念,总结了形成庭院格局的3种设计模式和庭院的3种设计模式。试图创造建筑和庭院“共舞”的校园环境,探寻其连续而整体的、丰富而多层次的美,是本设计与研究的努力目标。     

Founding Pioneers of IVF: Independent innovative researchers generating livebirths within 4 years of the first birth

In this 40th anniversary year of the first IVF live birth, it is pertinent to look at all those teams endeavouring to generate live births from this unique technology and who succeeded within 4 years of the first. There were 9 teams who achieved this and a further 3 who were successful soon after, by the end of 1982. This historical review is compiled by 2 authors who were actively engaged in the field of IVF at the time of the first birth and who have remained active in Reproductive Medicine throughout their professional lives. They bring intimate and relevant knowledge of those pioneer researchers from the early years who can be classified as the "Founding Pioneers" of IVF.     

Reductive Alkaline Release of N‐Glycans Generates a Variety of Unexpected,Useful Products

Release of O‐glycans by reductive β‐elimination has become routine in many glyco‐analytical laboratories and concomitant release of N‐glycans has repeatedly been observed. Revisiting this somewhat forgotten mode of N‐glycan release revealed that all kinds of N‐glycans including oligomannosidic and complex‐type N‐glycans from plants with 3‐linked fucose and from mammals with or without 6‐linked fucose and with sialic acid could be recovered. However, the mass spectra of the obtained products revealed very surprising facts. Even after 16 h incubation in 1 M sodium borohydride, a large part of the glycans occurred in reducing form. Moreover, about one third emerged in the form of the stable amino‐functionalized 1‐amino‐1‐deoxy‐glycitol. When avoiding acidic conditions, considerable amounts of glycosylamine were observed. In addition, a compound with a reduced asparagine and de‐N‐acetylation products, in particular of sialylated glycans, was seen. The relative yields of the products reducing glycosylamine, reducing N‐glycan, 1‐amino‐1‐deoxy‐glycitol or glycitol could be controlled by the release conditions, foremost by temperature and borohydride concentration. Thus, chemical release of N‐glycans constitutes a cost‐saving alternative to enzymatic hydrolysis for the preparation of precursors for the production of reference compounds for various formats of N‐glycan analysis. Moreover, it allows to obtain a stable amino‐functionalized glycan derivative, which can be employed to construct glycan arrays or affinity matrices.     

Long‐term increases in tropical flowering activity across growth forms in response to rising CO2 and climate change

Mounting evidence suggests that anthropogenic global change is altering plant species composition in tropical forests. Fewer studies, however, have focused on long‐term trends in reproductive activity, in part because of the lack of data from tropical sites. Here, we analyze a 28‐year record of tropical flower phenology in response to anthropogenic climate and atmospheric change. We show that a multidecadal increase in flower activity is most strongly associated with rising atmospheric CO₂ concentrations using yearly aggregated data. Compared to significant climatic factors, CO₂ had on average an approximately three‐, four‐, or fivefold stronger effect than rainfall, solar radiation, and the Multivariate ENSO Index, respectively. Peaks in flower activity were associated with greater solar radiation and lower rainfall during El Niño years. The effect of atmospheric CO₂ on flowering has diminished over the most recent decade for lianas and canopy trees, whereas flowering of midstory trees and shrub species continued to increase with rising CO₂. Increases in flowering were accompanied by a lengthening of flowering duration for canopy and midstory trees. Understory treelets did not show increases in flowering but did show increases in duration. Given that atmospheric CO₂ will likely continue to climb over the next century, a long‐term increase in flowering activity may persist in some growth forms until checked by nutrient limitation or by climate change through rising temperatures, increasing drought frequency and/or increasing cloudiness and reduced insolation.