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171.
Social media data are being increasingly used in conservation science to study human–nature interactions. User-generated content, such as images, video, text, and audio, and the associated metadata can be used to assess such interactions. A number of social media platforms provide free access to user-generated social media content. However, similar to any research involving people, scientific investigations based on social media data require compliance with highest standards of data privacy and data protection, even when data are publicly available. Should social media data be misused, the risks to individual users' privacy and well-being can be substantial. We investigated the legal basis for using social media data while ensuring data subjects’ rights through a case study based on the European Union's General Data Protection Regulation. The risks associated with using social media data in research include accidental and purposeful misidentification that has the potential to cause psychological or physical harm to an identified person. To collect, store, protect, share, and manage social media data in a way that prevents potential risks to users involved, one should minimize data, anonymize data, and follow strict data management procedure. Risk-based approaches, such as a data privacy impact assessment, can be used to identify and minimize privacy risks to social media users, to demonstrate accountability and to comply with data protection legislation. We recommend that conservation scientists carefully consider our recommendations in devising their research objectives so as to facilitate responsible use of social media data in conservation science research, for example, in conservation culturomics and investigations of illegal wildlife trade online.  相似文献   
172.
Ongoing loss of biological diversity is primarily the result of unsustainable human behavior. Thus, the long-term success of biodiversity conservation depends on a thorough understanding of human–nature interactions. Such interactions are ubiquitous but vary greatly in time and space and are difficult to monitor efficiently at large spatial scales. However, the Information Age also provides new opportunities to better understand human–nature interactions because many aspects of daily life are recorded in a variety of digital formats. The emerging field of conservation culturomics aims to take advantage of digital data sources and methods to study human–nature interactions and thus to provide new tools for studying conservation at relevant temporal and spatial scales. Nevertheless, technical challenges associated with the identification, access, and analysis of relevant data hamper the wider adoption of culturomics methods. To help overcome these barriers, we propose a conservation culturomics research framework that addresses data acquisition, analysis, and inherent biases. The main sources of culturomic data include web pages, social media, and other digital platforms from which metrics of content and engagement can be obtained. Obtaining raw data from these platforms is usually desirable but requires careful consideration of how to access, store, and prepare the data for analysis. Methods for data analysis include network approaches to explore connections between topics, time-series analysis for temporal data, and spatial modeling to highlight spatial patterns. Outstanding challenges associated with culturomics research include issues of interdisciplinarity, ethics, data biases, and validation. The practical guidance we offer will help conservation researchers and practitioners identify and obtain the necessary data and carry out appropriate analyses for their specific questions, thus facilitating the wider adoption of culturomics approaches for conservation applications.  相似文献   
173.
唐庚  何张涵  王勇  王伟  王永军  段明 《化工环保》2012,40(3):315-321
以L-苯丙氨酸、长链烷基(C12/C14/C16/C18)酰氯和聚乙二醇单甲醚(MPEG,Mn=350,550,750,1 000 g/mol)为原料,合成了一系列新型非离子型表面活性剂N-长链碳酰基-L-苯丙氨酸单甲基聚乙二醇酯(Rn-L-MPEG),系统研究了表面张力、界面张力和土壤吸附性与其结构之间的关系。结果表明:随着MPEG分子量的增大,Rn-L-MPEG的表面张力逐渐下降;随着酰氯中烷基链的增长,Rn-L-MPEG的表面张力呈现增大趋势,系列表面活性剂中R12-L-MPEG1000具有最低的表面张力28.11 mN/m;Rn-L-MPEG的界面张力随分子结构变化的规律同表面张力;随着MPEG分子量的增大,Rn-L-MPEG的饱和吸附量逐渐增大,随着酰氯中烷基链的增长,Rn-L-MPEG的饱和吸附量呈现下降趋势。  相似文献   
174.
ABSTRACT: The fate of contaminants in large water bodies is highly influenced by the transfer of flow and solutes across the water sediment interface. In this paper, an analytical model is presented where flow in both sediment bed and open channel is coupled at the interface through a boundary layer occupying the upper part of the sediment bed. The presence of this layer allows not only the capture of the inertia effects through a drag term in the generalized Darcy's equation, but also the specification of different soil parameters for the two porous zones. The flow is advective and driven by wave action along the water surface. The resulting system is solved for the pressure and flux in each sediment layer. The generated transport velocity fields are linked to a random walk simulation that is used to examine the trajectories of solute particles. Comparison of these trajectories against experimental tracer tests suggests a pattern very similar to the one attributed to the presence of surface mounds. The results clearly show the significance of the boundary layer and the drag term for soil with high permeability and the impact of both the thickness of the boundary layer and the length of the gravity wave relative to the depth of the water channel on the transport and exchange across the interface. The paper also examines the sensitivity of the mass exchange to the permeability of the two porous zones.  相似文献   
175.
The two major processes of decision making, behavioral interactions and decision analysis, are discussed. Comparisons are made between the Delphi and NGT methods of behavioral interaction. Three different types of decision analysis are compared, including the Goals Achievement Matrix, Concordance Analysis, and the Simple Multi-Attribute Rating Technique. Decision making problems characteristic of environmental studies are reviewed. A method of decision making that combines the best qualities of other methods is suggested. The overall purpose of this paper is to make the technical knowledge of decision making useful to environmentalists, businessmen, citizens, and politicians, and to improve the process of policy making in environmental studies.  相似文献   
176.
White-rot fungi applied for soil bioremediation have to compete with indigenous soil microorganisms. The effect of competition on both indigenous soil microflora and white-rot fungi was evaluated with regard to degradation of polycyclic aromatic hydrocarbons (PAH) with different persistence in soil. Sterile and non-sterile soil was artificially contaminated with 14C-labeled PAH consisting of three (anthracene), four (pyrene, benz[a]anthracene) and five fused aromatic rings (benzo[a]pyrene, dibenz[a,h]anthracene). The two fungi tested,Dichomitus squalens and Pleurotus ostreatus, produced similar amounts of ligninolytic enzymes in soil, but PAH mineralization by P. ostreatus was significantly higher. Compared to the indigenous soil microflora, P.ostreatus mineralized 5-ring PAH to a larger extent, while the indigenous microflora was superior in mineralizing 3-ring and 4-ring PAH. In coculture the special capabilities of both soil microflora and P. ostreatus were partly restricted due to antagonistic interactions, but essentially preserved. Thus, soil inoculation with P. ostreatus significantly increased the mineralization of high-molecular-weight PAH, and at the same time reduced the mineralization of anthracene and pyrene. Regarding the mineralization of low-molecular-weight PAH, the stimulation of indigenous soil microorganisms by straw amendment was more efficient than application of white-rot fungi.  相似文献   
177.
Current evolution of wireless personal communications has necessitated a comprehensive understanding of electromagnetic interactions between handset antennas and nearby human body. In this work the handset–human body interactions were evaluated in various configurations (with and without user’s hand; with and without user’s head, and combinations of them) in order to obtain statistical averages of the overall performance for system link evaluations. The measurements were performed using the random-field measurement (RFM) method, and thus the acquisition of large amounts of data about human–mobile phone interactions in typical operating environment with measured the received RF signal strength (RXLEV), and the output power level (TXLEV) on mobile station. The RXLEV and the TXLEV was measured over the air interface in the networks on two Bulgarian GSM mobile operators (Mtel and Vivatel). Both uplink and downlink measurements were performed in urban area in three cities. Each measurements were carried out in a building included both line-of-sight and non-line-of-sight propagation of the electromagnetic waves between mobile station and base station. The results showed that the user’s hand and head induces more significant changes on the received RF signal strength in case when broadcast control channel (BCCH) levels are up to −60 dBm. Also the alterations of receiving RF signal strength and output power level of the MS are influence stronger from the larger size of the hand and head of user. The influence from presence of the head and hand of the subscriber in talk position over the alteration of the receiving RF signal strength is in boundaries from 14.21 dBm to 19.1 dBm (man) and from 8.5 dBm to 12.05 dBm (woman). The presence of the user’s hand and head increased the output power level of mobile station with 12 dBm to 14 dBm (man) and with 10 dBm to 12 dBm (woman) compare to output power level without user’s hand and head.  相似文献   
178.
卢毅  陈家军  林婷 《环境科学》2010,31(1):205-210
醇类助溶剂单一使用及复配表面活性剂使用去除砂土中多氯联苯(PCBs)的关键是增溶和降低界面张力.通过降低界面张力实验和振荡增溶实验分析了醇类助溶剂单一使用对多氯联苯界面张力的降低作用和增溶作用,以及醇类复配Triton X-100使用时醇对Triton X-100降低界面张力和增溶PCBs的影响.结果表明,醇-PCBs油的界面张力与醇浓度、醇含碳原子数均呈负相关,甲醇、乙醇、异丙醇的最佳解吸浓度分别为70%、55%、40%,最佳解吸效率达90%以上;Triton X-100-PCBs油界面张力与Triton X-100浓度呈负相关,Triton X-100浓度低于3 000 mg/L时复配10%乙醇、10%异丙醇比单一Triton X-100振荡洗脱效率低,Triton X-100浓度在3 000~7 500 mg/L时3组差异不大,Triton X-100浓度为10 000 mg/L时单一、10%乙醇、10%异丙醇TritonX-100溶液解吸效率分别为80.9%、90.36%、89.36%.表明醇类单一使用对降低界面张力与增溶均有很好的效果,但需要其体积分数达40%以上;醇类复配Triton X-100时醇的存在弱化了Triton X-100增溶和降低界面张力的作用,乙醇与异丙醇弱化作用差异性不大,当Triton X-100浓度高于3 000 mg/L时,弱化作用不显著.  相似文献   
179.
In central Mexico, it is common for farmers to retain useful trees in abandoned lands after maize cultivation, creating a park-like landscape of scattered trees for extensive livestock grazing, among other land uses (mature forests, secondary forests, and livestock grazing in secondary forests). Among these trees Acacia cochliancantha and Ipomoea arborescens are the most common species associated with this land use in the region. The objective of this study was to assess the effects of both tree species on soil N and P recycling. To this end, we measured N and P concentrations in leaves of both species; and the seasonal N and P (total and dissolved) content in the litter, and total N and P, inorganic N, and bicarbonate-extractable-P concentrations, and the N transformations in the soil, in samples collected under crown of Acacia and Ipomoea and in open areas. Trees of different species varied in their capacity to cycle N. The leaves of Acacia were richer in N than those of Ipomoea (29.7 and 25.0 mg N g−1, respectively), and nutrient resorption was higher in leguminous trees than in Ipomoea (by 20% in the case of N, and 35% in the case of P). Acacia trees had higher effects on soils than Ipomoea trees, like consistent increases of N concentrations (by 30% in the case of total N, and by 50% in the case of inorganic N) and transformations (N mineralization and nitrification in rainy season increases by a factor of 20 and 36, respectively). On the other hand, Ipomoea produced senescent leaves and accumulated forest litter with less P concentration (0.8 and 0.7 mg P g−1, respectively) in relation to Acacia (senescent leaves: 1.3 mg P g−1; litter: 1.1 mg P g−1), reflecting the lower availability of the nutrient in the soil. The total litter N and P pools decreased in the rainy season under crown of both species, as the dissolved P pool did. The total soil N and P concentrations did not change with sampling season. However, potential N transformations and bicarbonate P under both species were higher in dry season than in rainy season samples. Comparison with other land uses in the region suggests that the AcaciaIpomoea system cycles low quantity of nutrients, but there are no notable differences in the availability of P in the soils. These results demonstrate that scattered trees improve the N and P cycling following the discontinuation of agricultural practices, and the effects will vary depending on the tree species.  相似文献   
180.
The large range of body-mass values of soil organisms provides a tool to assess the ecological organization of soil communities. The goal of this paper is to identify graphical and quantitative indicators of soil community composition and ecosystem functioning, and to illustrate their application to real soil food webs. The relationships between log-transformed mass and abundance of soil organisms in 20 Dutch meadows and heathlands were investigated. Using principles of allometry, maximal use can be made of ecological theory to build and explain food webs. The aggregate contribution of small invertebrates such as nematodes to the entire community is high under low soil phosphorus content and causes shifts in the mass–abundance relationships and in the trophic structures. We show for the first time that the average of the trophic link lengths is a reliable predictor for assessing soil fertility responses. Ordered trophic link pairs suggest a self-organizing structure of food webs according to resource availability and can predict environmental shifts in ecologically meaningful ways. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to all users.  相似文献   
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