武汉东湖浮游病毒的丰度及多样性

运用透射电镜及荧光显微技术 ,对富营养化的武汉东湖中浮游病毒丰度及多样性进行了研究。电镜观察和计数结果显示 ,东湖中浮游病毒的丰度达到 10 8个 /mL。荧光显微镜计数结果约是电镜计数结果的 2 72倍 ,差异极显著 (P <0 0 1)。在东湖超富营养区的水样中观察到了多种与各种病毒形态类似的颗粒 ,其中大部分与噬菌体和噬藻体类似 ,具多种形态的尾部和六边形头部。还有一些线状、杆状、子弹形等形态的病毒粒子。研究结果显示东湖水环境中的浮游病毒不仅丰度极高 ,而且种类丰富。提示浮游病毒在东湖水环境和水生态系统中可能扮演重要角色。     

Tree dynamics and co‐existence in the montane–sub‐alpine ecotone: the role of different light‐induced strategies

Questions: Is light availability the main factor driving forest dynamics in Pyrenean sub‐alpine forests? Do pines and firs differ in growth, mortality and morphological response to low light availability? Can differences in shade tolerance affect predictions of future biome changes in Pyrenean sub‐alpine forests in the absence of thermal limitation? Location: Montane–sub‐alpine ecotones of the Eastern Pyrenees (NE Spain). Methods: We evaluated morphological plasticity, survival and growth response of saplings of Scots pine, mountain pine and silver fir to light availability in a mixed forest ecotone. For each species, we selected 100 living and 50 dead saplings and measured size, crown morphology and light availability. A wood disk at root collar was then removed for every sapling, and models relating growth and mortality to light were obtained. Results: Fir had the lowest mortality rate (<0.1) for any given light condition. Pines had comparable responses to light availability, although in deep shade Scots pine risked higher mortality (0.35) than mountain pine (0.19). Pines and fir developed opposing strategies to light deprivation: fir employed a conservative strategy based on sacrificing height growth, whereas pines enhanced height growth to escape from shade, but at the expense of higher mortality risk. Scots pine showed higher plasticity than mountain pine for all architectural and morphological traits analysed, having higher adaptive capacity to a changing environment. Conclusions: Our results support the prediction of future biome changes in Pyrenean sub‐alpine forests as silver fir and Scots pine may find appropriate conditions for colonizing mountain pine‐dominated stands due to land‐use change‐related forest densification and climate warming‐related temperature increases, respectively.     

定量检测猕猴血清中重组人源化抗狂犬病毒单克隆抗体间接ELISA法的建立

目的：建立定量检测血清中重组人源化抗狂犬病毒单克隆抗体（HuMabs）NM57的间接ELISA法,为药代动力学研究提供一种简单快速的方法。方法：采用狂犬病毒糖蛋白包被酶标板、HRP标记的IgG-Fc段为标记抗体,建立定量检测HuMabsNM57的间接ELISA法,并对其特异性、灵敏度、精密度及准确度进行检测。结果：间接ELISA法检测HuMabsNM57的灵敏度为5ng／mL,组内及组间精密度分别为2．6％-6．0％、8．5％-11．3％。结论：建立了灵敏度高、特异性强的检测HuMabs NM57的间接ELISA法,精密度及准确度均符合药代动力学要求,可用于猕猴及人血清中HuMabsNM57的检测。     

QTL analysis of leaf morphology in tetraploid Gossypium (cotton)

Molecular markers were used to map and characterize quantitative trait loci (QTLs) determining cotton leaf morphology and other traits, in 180 F₂ plants from an interspecific cross between a Gossypium hirsutum genotype carrying four morphological mutants, and a wild-type Gossypium barbadense. The prominent effects of a single region of chromosome 15, presumably the classical ”Okra-leaf” locus, were modified by QTLs on several other chromosomes affecting leaf size and shape. For most traits, each parent contained some alleles with positive effects and others with negative effects, suggesting a large potential for adapting leaf size and shape to the needs of particular production regimes. Twenty one QTLs/loci were found for the morphological traits at LOD≥3.0 and P≤0.001, among which 14 (63.6%) mapped to D-subgenome chromosomes. Forty one more possible QTLs/loci were suggested with 2.0≤LOD<3.0 and 0.001<P≤0.01. Among all of the 62 possible QTLs (found at LOD≥2.0 and P≤0.01) for the 14 morphological traits in this study, 38 (61.3%) mapped to D-subgenome chromosomes. This reinforces the findings of several other studies in suggesting that the D-subgenome of tetraploid cotton has been subject to a relatively greater rate of evolution than the A-subgenome, subsequent to polyploid formation. Received: 26 April 1999 / Accepted: 30 July 1999     

高寒草甸植物物种丧失对草原毛虫的影响

植物多样性是调控食物网结构和生态系统功能最重要的生物因素, 植物多样性丧失深刻影响食草动物, 但由于小型食草动物种群数量波动明显、统计随机性较大等困难, 我们对植物多样性丧失如何影响小型食草动物依然知之甚少。基于在青藏高原高寒草甸设置的长期植物物种剔除试验, 本研究于2016-2020年7-8月连续调查了植物物种剔除各处理中草原毛虫(Gynaephora alpherakiif)的数量, 分析了植物物种及功能群丧失对草原毛虫的影响。结果表明, 虽然时空差异及统计随机性是影响草原毛虫数量变化的主要因素, 但植物物种剔除介导的群落差异对草原毛虫数量的影响依然显著: (1)在各观测时段, 优势种线叶嵩草(Kobresia capillifolia)的丧失导致群落中草原毛虫数量显著减少; 禾草类物种丧失也会减少草原毛虫数量, 但其影响仅在8月显著; (2)杂类草物种丧失通过增加群落中禾草物种多度, 可增加草原毛虫数量; 豆科物种丧失使莎草增多, 也会增加草原毛虫数量; (3)各植物功能群部分物种剔除并未显著影响草原毛虫数量。本研究证实了高寒草甸中草原毛虫数量会因优势植物嵩草和禾草的多度减少或禾草物种丧失而显著减少, 但群落总生物量、个体数和物种丰富度、豆科多度以及各功能群植物同比减少, 都对草原毛虫数量没有明显影响。这些结果说明在随机作用主导下, 植物群落中的特定功能群相对多度(而非物种多样性)变化深刻影响草原毛虫适合度, 进而影响生态系功能及服务; 未来生物多样性研究及草地虫害生物防控中应更多考虑统计随机性及植物功能多样性对小型食草动物的影响。     

Multiple Neurite Formation in Neuroblastoma Cell Lines by Griseolic Acid, a Potent Inhibitor of Cyclic Nucleotide Phosphodiesterases

The morphological change of several neuroblastoma cell lines induced by griseolic acid, a novel and potent inhibitor of cyclic nucleotide phosphodiesterase (PDE), was examined. In the cell lines tested, Neuro-2a (a murine neuroblastoma cell line) showed dose-dependent (1 microM-1 mM) neurite extension. Griseolic acid markedly increased the intracellular cyclic AMP level of Neuro-2a cells, suppressed DNA synthesis (82% at 1 mM), and induced multipolar (multiple-neurite-bearing)-type neuritogenesis. A similar type of neurite outgrowth was induced by 8-bromo-cyclic AMP, which also elevated the intracellular cyclic AMP concentration. In contrast, when Neuro-2a cells were treated with retinoic acid, neurite formation was of the monopolar (single-neurite-bearing) type. Papaverine and theophylline, which have been frequently used as PDE inhibitors, failed to induce these morphological changes up to 1 mM, probably owing to the lesser potency of these compounds as compared with griseolic acid on the inhibition of PDE. Retinoic acid, theophylline, and papaverine were ineffective at elevating the intracellular cyclic AMP level. These results suggest that multipolar-type cell shape change in Neuro-2a cells is correlated with the accumulation of intracellular cyclic AMP and that griseolic acid is a useful compound to induce neuroblastoma cells into terminal differentiation.     

关于提高血气分析仪测量精度的探讨

血气分析已广泛用于昏迷、休克、严重外伤的危急病人的血液酸碱度、氧分压、二氧化碳分压的测量。测量数据的准确性至关重要。本文对与测量精度有关的几个环节如计量检定、质控与定标、样本采集与测量、日常维护与故障处理进行探讨,提出提高血气分析精度的解决方案。     

白骨壤幼苗的形态特征及其生物量

白骨壤1年生幼苗的株高、基径、根长、呼吸根高、叶面积以及根、茎、枝、叶、胎生苗和全株生物量等计量指标,呈现算术平均值>中值>众值组段中点的规律,符合正偏态分布节数、叶数、呼吸根数、胎生苗数等计数指标的算术平均值和中值相等,二者大于或等于众值组段中点.研究发现白骨壤1年生幼苗能生长指状呼吸根以及开花、结果和发育胎生苗,而且胎生苗成熟后直接萌发形成新的幼苗.根据实测的数据,采用一元线性回归、多元线性回归和非线性回归拟合了白骨壤1年生幼苗主要形态因子和生物量的回归模型.     

How to measure,report and verify soil carbon change to realize the potential of soil carbon sequestration for atmospheric greenhouse gas removal

There is growing international interest in better managing soils to increase soil organic carbon (SOC) content to contribute to climate change mitigation, to enhance resilience to climate change and to underpin food security, through initiatives such as international ‘4p1000’ initiative and the FAO's Global assessment of SOC sequestration potential (GSOCseq) programme. Since SOC content of soils cannot be easily measured, a key barrier to implementing programmes to increase SOC at large scale, is the need for credible and reliable measurement/monitoring, reporting and verification (MRV) platforms, both for national reporting and for emissions trading. Without such platforms, investments could be considered risky. In this paper, we review methods and challenges of measuring SOC change directly in soils, before examining some recent novel developments that show promise for quantifying SOC. We describe how repeat soil surveys are used to estimate changes in SOC over time, and how long‐term experiments and space‐for‐time substitution sites can serve as sources of knowledge and can be used to test models, and as potential benchmark sites in global frameworks to estimate SOC change. We briefly consider models that can be used to simulate and project change in SOC and examine the MRV platforms for SOC change already in use in various countries/regions. In the final section, we bring together the various components described in this review, to describe a new vision for a global framework for MRV of SOC change, to support national and international initiatives seeking to effect change in the way we manage our soils.