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Daniela Cianelli Luciana Sabia Maurizio Ribera dAlcal Enrico Zambianchi 《Ecological modelling》2009,220(19):2380-2392
In marine ecosystems ecological and environmental conditions continuously change, possibly supporting the wide range of phytoplankton species coexisting in aquatic environments. Phytoplankton communities are not homogeneously distributed in the water column due to the spatial and temporal variability of turbulent mixing and the concurrent biological response. In this paper an individual-based model (Lagrangian method) simulating the basic physiology of two coexisting phytoplankton species has been developed. The species, sharing the same availability of light and nutrient resource, are characterized by different photo-physiological parameters. The spatial and temporal evolution of turbulent mixing is simulated introducing vertical profiles of measured eddy diffusivity. Three case studies have been examined to analyze the role of environment–individual interactions in determining bloom conditions for both the selected species. The organisms experience recurrent fluctuations of light, temperature, and nutrient concentration gradients, due to the turbulent mixing in the water column, which have significant effects on the growth of the phytoplankton species. In all the numerical experiments, the temporal and spatial variability of different forcings do not support the prevalence of one species over the other over the time scale typical of a phytoplankton bloom.A well mixed water column favours the growth of both the populations while a variable mixing regime limits their growth reducing the photophysiological differences between the species. 相似文献
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In this article, I present a two-patch metapopulation model with locally explicit dynamics to study the effect of spatial heterogeneity and dispersal upon population interactions with variable or conditional outcomes. These are interactions that may be either detrimental or beneficial for each species depending on the balance of the density-dependent costs and benefits involved. The local dynamics respond to density-dependent α-interaction functions that may change sign, thus yielding a diversity of possible local outcomes for the association in terms of type of interaction and in the number of stable solutions. The spatiotemporal model predicts that the fragmentation of space and dispersal between patches may cause further variation in these outcomes. First, the demographic performance of a species in the association is enhanced if migrations cause a proportional increase of individuals of its own species; being so, a victim may become a mutualist or an exploiter, an excluded species may invade, and a good competitor may overcome its own carrying capacity: the ‘enhancement effect of dispersal’; a sort of rescue effect in source-sink dynamics. The underlying mechanisms involve an interplay between density-dependent effects of dispersal per se and the relative local and global average α-interaction functions, which involve costs and benefits at both the local and regional level that may either counteract or reinforce each other; thus, localities and/or populations may change dynamically their sink or source role in the spatial dynamics. A significant insight arises herewith: in the context of variable or conditional interactions the concept of the role of a species does not make strict sense; it becomes a spatiotemporal dynamic quality. Second, regardless of which species disperses, bifurcation of equilibria may occur in those patches that receive the migrating individuals, and annihilation of equilibria in those from where migration leaves; thus, the number of equilibria increases or decreases accordingly. 相似文献
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溶液中多种金属离子共存对毛木耳生物吸附能力的影响 总被引:2,自引:0,他引:2
用毛木耳(Auricularia polytricha)菌丝体的死细胞作为生物吸附剂吸附溶液中的Cd 2+、Cu 2+和Pb 2+.用原子吸收分光光度计测定吸附前后溶液金属离子的变化,研究了溶液中两种离子共存对毛木耳吸附能力的影响.结果表明:溶液中Pb2+的存在抑制了毛木耳对Cd2+的吸附,是负向干扰;Cd2+的存在促进了毛木耳对pb2+的吸附,是正向干扰;Cu2+的存在促进了毛木耳对pb2+的吸附,是正向干扰;Pb2+的存在抑制了毛木耳对Cu2+的吸附,是负向干扰;Cd2+对Cu2+的影响作用不如Cu2+对Cd2+的影响明显.实验结果为毛木耳作为重金属污染废水的处理材料提供理论依据. 相似文献
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党的二十大提出要建设人与自然和谐共生的现代化,美丽中国建设是社会主义现代化强国的重要目标之一,是中国式现代化的基本内涵和重要表征。面对新时代美丽中国建设整体部署还需进一步明确的现实需求,本文在总结美丽中国建设进展成效的基础上,分析识别推进美丽中国建设面临的主要问题与挑战,提出推进美丽中国建设的总体思路和目标路径,围绕绿色低碳发展、环境治理、生态保护、应对气候变化、生态环境治理体系和治理能力现代化等美丽中国建设重点领域,提出推进加快发展方式绿色转型、推进国家重大战略绿色发展、推动环境污染防治、打造美丽宜居城乡、提升生态系统多样性、稳定性和持续性、推进碳达峰碳中和、构建生态环境风险防控体系、共建清洁美丽世界等8个方面美丽中国建设重点任务。 相似文献
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Studies evaluating human–wildlife interactions (HWIs) in a conservation context often include psychometric scales to measure attitudes and tolerance toward wildlife. However, data quality is at risk when such scales are used without appropriate validation or reliability testing, potentially leading to erroneous interpretation or application of findings. We used 2 online databases (ProQuest Psych Info and Web of Science) to identify published HWI studies that included attitude and tolerance. We analyzed these studies to determine the methods used to measure attitudes or tolerance toward predators and other wildlife; determine the proportion of these methods applying psychometric scales; and evaluate the rigor with which the scales were used by examining whether the psychometric properties of validity and reliability were reported. From 2007 to 2017, 114 published studies were identified. Ninety-four (82%) used questionnaires and many of these (53 [56%]) utilized a psychometric scale. Most scales (39 [74%]) had at least 1 test of reliability reported, but reliance on a single test was notable, contrary to recommended practice. Fewer studies (35 [66%]) reported a test of validity, but this was primarily restricted to structural validity rather than more comprehensive testing. Encouragingly, HWI investigators increasingly utilized the necessary psychometric tools for designing and analyzing questionnaire data, but failure to assess the validity or reliability of psychometric scales used in over one-third of published HWI attitude research warrants attention. We advocate incorporation of more robust application of psychometric scales to advance understanding of stakeholder attitudes as they relate to HWI. 相似文献
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紫外线 (UV) 是一种高效、绿色的消毒技术,广泛应用于气、水和物体表面的病原微生物灭活。远C波段UV (远UV-C,200~230 nm) 消毒所需剂量辐照对人体的伤害尚未被发现,表明远UV-C具备人机共存原位消毒的潜力,因此该技术近期受到关注。概述了远UV-C光源、灭活机制和辐照安全性方面的研究进展:输出主峰位和半峰宽分别为222 nm和4 nm的KrCl准分子灯是最为成熟的消毒用远UV-C光源;远UV-C通过蛋白质损伤和核酸干扰2种途径实现病原微生物灭活,灭活能力较传统UV-C (如254 nm) 更强;尚未发现消毒所需剂量的远UV-C辐照导致的健康危害,如红斑和角膜炎。而在实际应用中,应谨慎对待高剂量远UV-C辐照暴露,确保在现有实验证据基础上,逐步提高远UV-C安全使用的剂量阈值,并考虑与通风系统或臭氧淬灭系统协同使用以避免伴生臭氧造成的二次伤害。本文旨在为远UV-C在高效灭活病原微生物、阻断高传染性疾病传播领域的应用提供参考。 相似文献
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城市规划中的文化视野:以昆明市为例 总被引:1,自引:0,他引:1
城市文化生态建设不仅对城市环境保护起到重要作用,而且可以促进城市经济发在城市规划中应摈弃以环境代价换取经济效益的错误思潮蛤论,生态环境三者有机结合起来,实现城市优美人居环境和良好经济效益的双赢战略,走可持续发展之路。 相似文献
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The large number of radio frequency (RF) transmitters employed in modern marine platforms requires that they operate in mutual
coexistence while posing no danger to operators and equipment despite the limited available physical space. A key to the successful
system integration is the control of the electromagnetic environment on the ships’ topsides, which might pose radiation hazards
(RADHAZ) to personnel (HERP). HERP are caused by transmitter antenna installations that generate intentional EM radiation
in excess of the safe levels in zones of personnel activity. Radiation safety to personnel is achieved when the average radiation
power density is below the permissible exposure limits (PEL) for HERP at locations of personnel activity and medical equipment
operation. This paper describes the analysis tools and techniques for the evaluation of HERP on marine platforms. The same
approaches could be employed in the analysis of land site antenna deployment scenarios. 相似文献
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Deseada Parejo Étienne Danchin Nadia Silva Joel F. White Amélie N. Dreiss Jesús M. Avilés 《Behavioral ecology and sociobiology》2008,62(10):1569-1579
Sympatric species sharing requirements are competitors, but recent evidence suggests that heterospecifics may also be used
as a source of information. The heterospecific habitat copying hypothesis proposes that individuals of one species might use
information inadvertently produced by the breeding performance of individuals of other species to assess habitat quality whenever
the two species share needs. In this study, we provide the first experimental test of this hypothesis by examining whether
the manipulated reproductive success of blue tits (Cyanistes caeruleus) is used as heterospecific inadvertent social information (ISI) in breeding-habitat selection by sympatric great tits (Parus major). The reproductive success of blue tits was manipulated 1year at the scale of patches by transferring nestlings from decreased
to increased patches. No evidence was found of great tits using the reproductive success of blue tits as a source of heterospecific
ISI. However, dispersal decisions by adult great tits correlated with information on con- and heterospecific densities, which
constitute other sources of ISI. As density and breeding performance are tightly intertwined forms of information, the difficulty
in distinguishing between them might lead great tits to use heterospecific ISI more in the form of density than breeding performance
when making dispersal decisions. 相似文献