Gardening the genome: DNA methylation in Arabidopsis thaliana

DNA methylation has two essential roles in plants and animals - defending the genome against transposons and regulating gene expression. Recent experiments in Arabidopsis thaliana have begun to address crucial questions about how DNA methylation is established and maintained. One cardinal insight has been the discovery that DNA methylation can be guided by small RNAs produced through RNA-interference pathways. Plants and mammals use a similar suite of DNA methyltransferases to propagate DNA methylation, but plants have also developed a glycosylase-based mechanism for removing DNA methylation, and there are hints that similar processes function in other organisms.     

江苏地区观赏草及其在园林中的应用

简要阐述江苏地区观赏草的种类、习性、特征、观赏价值及其在园林中的应用。     

樟科观赏树种资源及园林应用

我国具有丰富的樟科园林植物,在现有的资源状况基础上,园林推广应用可合理扩大范围,进一步充实快速发展的园林市场,同时对一些濒危植物的种群数量增加将产生积极影响。     

贵州野生小檗科木本植物的园林观赏特性及用途

通过调查及查阅有关资料,对贵州省野生小檗科木本植物45种1变种的观赏生物学特性进行了研究,并叙述了这些观赏植物的园林用途。     

Gardening and urban landscaping: significant players in global change

Global warming leads to shifts in vegetation types in given temperate environments. The fastest species movement is due to the globalized supply and use of exotic plants in gardening and urban landscaping. These standard practices circumvent dispersal limitations and biological and environmental stresses; they have three major global impacts: (i) the enhancement of biological invasions, (ii) the elevation of volatile organic compound emissions and the resulting increase in photochemical smog formation, and (iii) the enhancement of CO(2) fixation and water use by gardened plants. These global effects, none of which are currently considered in global-change scenarios, are increasingly amplified with further warming and urbanization. We urge for quantitative assessment of the global effects of gardening and urban landscaping.     

云南金丝桃属植物资源及其园林应用

本文在调查的基础上 ,报道了云南金丝桃属植物资源的物种多样性 ,地理分布及其生境 ,并阐述了其观赏特性及园林用途。     

福州左海公园园林绿化调查及种类配置分析

本文对福州左海公园园林植物种类及其配置进行统计、描述,测算其绿化面积及绿化率,分析种类配置的合理性,并提出可行性建议。     

Gardening by the psychomyiid caddisfly Tinodes waeneri: evidence from stable isotopes

Sedentary species face a trade-off between the benefits of exploiting food close to their homes and the cost of defending it. In aquatic systems, it has been suggested that some sedentary grazers can increase the range of circumstances under which they are at an advantage over mobile grazers by enhancing food resources within their feeding territories through ‘gardening’. We examined this for the retreat-building sedentary larvae of the caddis Tinodes waeneri, which are often dominant in the littoral of lakes. We hypothesised that T. waeneri gardens by fertilising its retreat (a fixed ‘gallery’ on which algae and other microorganisms grow), and that gardening would be more important in lower productivity lakes. We tested this by analysing the carbon and nitrogen stable isotope ratios of larvae, their galleries and the general background epilithon, collected from rocks in the littoral zones of six lakes spread across a natural nutrient gradient. We found evidence of nutrient recycling within the Tinodes gallery community in all lakes. Galleries were ¹⁵N-depleted compared to the epilithon, suggesting that algae on galleries preferentially assimilated ¹⁴N from larval excretions that were themselves ¹⁵N-depleted relative to the larval food source. Mixing model results indicate that galleries formed an important larval carbon and nitrogen source, with mean gallery dietary contributions of over 40% in at least one sample period in all lakes studied. Gallery contributions were greater between April and October than in January and, contrary to our initial hypothesis, greater in the more productive lakes of those surveyed. Nevertheless, T. waeneri galleries do act as a fertilised garden. ‘Gardening’ appears to be widespread in this species, and may affect productivity and patterns of nitrogen retention within the stony littoral of lakes.     

长白山杜鹃花科植物资源的园林应用

长白山位于我国吉林省东南部 ,中朝两国交界处 ,野生植物资源极其丰富 ,已越来越受到国内外植物科学工作者的重视。其中杜鹃花科植物资源有12种 ,对这一部分野生资源的园林应用进行研究 ,不仅可以促进野生植物资源的开发利用 ,而且可以极大的丰富城市绿化材料的种类。1　长白山杜鹃花科植物资源状况长白山杜鹃山科植物资源主要有以下几种 :种拉丁名类型株高花色花期细叶杜香Ｌｅｄｕｍ ｐａｌｕｓｔｒｅＬｖａｒ.ａｎｇｕｓｔｕｍＥ .ｂｕｓｃｈ 常绿小灌木 40～ 5 0ｃｍ白 6 - 7月宽叶杜香Ｌｅｄｕｍ ｐａｈｕｓｔｒｅＬ .ｖａｒ .ｄｉｌａ…     

Emotional Dynamics in the Age of Misinformation

According to the World Economic Forum, the diffusion of unsubstantiated rumors on online social media is one of the main threats for our society. The disintermediated paradigm of content production and consumption on online social media might foster the formation of homogeneous communities (echo-chambers) around specific worldviews. Such a scenario has been shown to be a vivid environment for the diffusion of false claim. Not rarely, viral phenomena trigger naive (and funny) social responses—e.g., the recent case of Jade Helm 15 where a simple military exercise turned out to be perceived as the beginning of the civil war in the US. In this work, we address the emotional dynamics of collective debates around distinct kinds of information—i.e., science and conspiracy news—and inside and across their respective polarized communities. We find that for both kinds of content the longer the discussion the more the negativity of the sentiment. We show that comments on conspiracy posts tend to be more negative than on science posts. However, the more the engagement of users, the more they tend to negative commenting (both on science and conspiracy). Finally, zooming in at the interaction among polarized communities, we find a general negative pattern. As the number of comments increases—i.e., the discussion becomes longer—the sentiment of the post is more and more negative.     

Biodiversity in the Age of Ecological Indicators

The multifarious nature of biodiversity is considered in relation to difficulties of definite determination and managerial mandates for monitoring. At a micro scale there is some convergence with the concept of community, but the linkage is largely lost in the spectra of temporal scope, spatial scales, successional seres, and taxonomic trajectories. Practicality points to selecting suitable suites of indicators as surrogates for particular purposes. Domains of partial ordering on multiple indicators constitute comparable collectives, whereas different domains require recognition of special situations. Theoretical treatise and practical process can proceed in parallel, with dialogue and cross-fertilization serving to invigorate and inspire; whereas compulsive concern for completeness and consistency can be counter-productive as well as unduly expensive. Inability to completely capture all aspects of biodiversity in one full formulation is interesting and integral to issues of biocomplexity.