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51.
Abstract Onosma echioides is a non-obligate serpentinophytic borage occurring discontinuously on calcareous and serpentine outcrops at the northwest limit of its range. Mean concentrations of Ca, Mg and heavy metals in root and shoot samples of eight populations from the two soil types were first determined. Subsequently, the genetic polymorphism of the same accessions was estimated by means of Amplified Fragment Length Polymorphism (AFLP) fingerprinting technique. Root and shoot samples from serpentine outcrops showed higher levels of Ni, Cr and Mg, and lower Ca/Mg ratios compared with those from calcareous soils. Based on 353 polymorphic AFLP bands, the two edaphic groups of populations showed comparable levels of genetic diversity. A remarkable genetic differentiation between populations and a high level of within-population genetic variance were found. Results of Mantel's test supported a significant correlation between genetic and geographical distances, while no difference in relation to the edaphic factor was detected. Molecular data suggested isolation as the key factor shaping the infraspecific genetic structure of O. echioides, which may be in relation with the short-distance, zoochorous systems of seed dispersal and pollination of this species. 相似文献
52.
ABSTRACT The established practice of forest ecosystem inventory and monitoring is recognised as a main support for terrestrial natural renewable resource survey programmes. Inventory and monitoring programmes focused on an overall assessment of ecosystem attributes evolving into global environmental survey programmes have been devised, but implementation is still quite contradictory. The state-of-the-art is discussed here, with special reference to the European Union and Italy. Topical issues are reviewed, with selective concern to: remote sensing capability, probability sampling, forest type (habitat) classification and landscape ecology, sustainable management indicators. Benefits brought by information technology are highlighted. Its development and the implementation of approaches based on a sound “per habitat” landscape ecological perspective will bring unique benefits, thus leading to an effective integration among sector surveys aimed at global environmental inventory/monitoring. 相似文献
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54.
P. W. Yawalkar S. J. Dhoble N. Thejo Kalyani R. G. Atram N. S. Kokode 《Luminescence》2013,28(1):63-68
The tris(8‐hydroxyquinoline)–aluminium complex is the most important and widely studied as electron transporting and green light emitting material. Alq3 and TbxAl(1‐x)q3 have been synthesized (where x = 0.1, 0.3, 0.5, 0.7 and 0.9) and blended films of Alq3 and TbxAl(1‐x)q3 with PMMA and PS at different percentage weight (wt%) concentrations (e.g., 0.1, 1, 5, 10, 25 and 50 wt%) have been prepared. The synthesized materials and their blended thin films have been characterized by a photoluminescence (PL) technique; the synthesis and PL characterization are reported in this paper. The synthesized metal complex shows bright emission of green light with blue light excitation (440 nm) and the prepared TbxAl(1‐x)q3 phosphor may be applicable in blue chip‐excited OLEDs for the newly developed wallpaper lighting technology. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
55.
Marina Corrêa Côrtes María Uriarte 《Biological reviews of the Cambridge Philosophical Society》2013,88(2):255-272
General principles about the consequences of seed dispersal by animals for the structure and dynamics of plant populations and communities remain elusive. This is in part because seed deposition patterns emerge from interactions between frugivore behaviour and the distribution of food resources, both of which can vary over space and time. Here we advocate a frugivore‐centred, process‐based, synthetic approach to seed dispersal research that integrates seed dispersal ecology and animal movement across multiple spatio‐temporal scales. To guide this synthesis, we survey existing literature using paradigms from seed dispersal and animal movement. Specifically, studies are discussed with respect to five criteria: selection of focal organisms (animal or plant); measurement of animal movement; characterization of seed shadow; animal, plant and environmental factors included in the study; and scales of the study. Most studies focused on either frugivores or plants and characterized seed shadows directly by combining gut retention time with animal movement data or indirectly by conducting maternity analysis of seeds. Although organismal traits and environmental factors were often measured, they were seldom used to characterize seed shadows. Multi‐scale analyses were rare, with seed shadows mostly characterized at fine spatial scales, over single fruiting seasons, and for individual dispersers. Novel animal‐ and seed‐tracking technologies, remote environmental monitoring tools, and advances in analytical methods can enable effective implementation of a hierarchical mechanistic approach to the study of seed dispersal. This kind of mechanistic approach will provide novel insights regarding the complex interplay between the factors that modulate animal behaviour and subsequently influence seed dispersal patterns across spatial and temporal scales. 相似文献
56.
Fei Chen Mengxing Dong Meng Ge Lingxiang Zhu Lufeng Ren Guocheng Liu Rong Mu 《基因组蛋白质组与生物信息学报(英文版)》2013,11(1):34-40
DNA sequencing using reversible terminators, as one sequencing by synthesis strategy, has garnered a great deal of interest due to its popular application in the second-generation high-throughput DNA sequencing technology. In this review, we provided its history of development, classification, and working mechanism of this technology. We also outlined the screening strategies for DNA polymerases to accommodate the reversible terminators as substrates during polymerization; particularly, we introduced the "REAP" method developed by us. At the end of this review, we discussed current limitations of this approach and provided potential solutions to extend its application. 相似文献
57.
Beata Kolesinska Dieter Seebach Faustin Kamena Peter Walde Markus Sauer Barbara Windschiegl Mira Meyer‐Ács Marc Vor der Brüggen Sebastian Giehring 《化学与生物多样性》2013,10(1):1-38
After a survey of the special role, which the amino acid proline plays in the chemistry of life, the cell‐penetrating properties of polycationic proline‐containing peptides are discussed, and the widely unknown discovery by the Giralt group (J. Am. Chem. Soc. 2002 , 124, 8876) is acknowledged, according to which fluorescein‐labeled tetradecaproline is slowly taken up by rat kidney cells (NRK‐49F). Here, we describe details of our previously mentioned (Chem. Biodiversity 2004 , 1, 1111) observation that a hexa‐β3‐Pro derivative penetrates fibroblast cells, and we present the results of an extensive investigation of oligo‐L ‐ and oligo‐D ‐α‐prolines, as well as of oligo‐β2h‐ and oligo‐β3h‐prolines without and with fluorescence labels ( 1 – 8 ; Fig. 1). Permeation through protein‐free phospholipid bilayers is detected with the nanoFAST biochip technology (Figs. 2–4). This methodology is applied for the first time for quantitative determination of translocation rates of cell‐penetrating peptides (CPPs) across lipid bilayers. Cell penetration is observed with mouse (3T3) and human foreskin fibroblasts (HFF; Figs. 5 and 6–8, resp.). The stabilities of oligoprolines in heparin‐stabilized human plasma increase with decreasing chain lengths (Figs. 9–11). Time‐ and solvent‐dependent CD spectra of most of the oligoprolines (Figs. 13 and 14) show changes that may be interpreted as arising from aggregation, and broadening of the NMR signals with time confirms this assumption. 相似文献
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59.
新型冠状病毒肺炎疫情对高校微生物学教学带来的挑战与发展机遇 总被引:2,自引:2,他引:0
突如其来的新型冠状病毒肺炎疫情使得网上在线教学成为这段时间的唯一教学方式。这一方面给高校的广大师生提出了新的挑战,但同时也给近年来一直进行的高等教育开放式教育教学改革发展潮流按下了加速键。《微生物学通报》以"第十七届全国微生物学教学和科研及成果产业化研讨会"为契机邀稿组织出版的这期"高等院校教学主题刊",很好地反映了近年来在开放式教育形势下我国微生物学教学改革与人才培养的最新进展和发展态势,其中也有文章介绍了疫情期间选择和使用线上教学技术的经验。期望该主题刊的出版有助于进一步促进广大微生物学教师强化互联网意识,打造"互联网+"思维,重塑课堂教学形态,通过广大教师间的教改经验交流与合作,进一步促进我国微生物学课程建设水平与教学质量的全面提升。 相似文献
60.
好氧反硝化生物脱氮技术的研究进展 总被引:4,自引:1,他引:3
好氧反硝化生物脱氮技术自提出以来,凭借能实现同步硝化反硝化、节省基建投资及运行费用等诸多优点,受到国内外环境领域学者的广泛关注。本文首先总结了近年来好氧反硝化菌种的筛选分离情况,以及环境因子对好氧反硝化菌脱氮效能的影响,包括溶解氧(dissolved oxygen,DO)、碳氮比(C/N)、温度等。然后深入探讨了好氧反硝化生物脱氮技术的原理,好氧反硝化过程中的关键功能基因及酶,同时介绍了分子生物技术在好氧反硝化研究过程中的应用,以及好氧反硝化生物脱氮技术在实际应用方面的研究现状。最后,基于目前的研究瓶颈问题,对未来好氧反硝化生物脱氮技术的研究方向提出了科学展望。 相似文献