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401.
IAN BRECKHEIMER NICK M. HADDAD WILLIAM F. MORRIS ANNE M. TRAINOR WILLIAM R. FIELDS R. TODD JOBE BRIAN R. HUDGENS AARON MOODY JEFFREY R. WALTERS 《Conservation biology》2014,28(6):1584-1593
Conserving or restoring landscape connectivity between patches of breeding habitat is a common strategy to protect threatened species from habitat fragmentation. By managing connectivity for some species, usually charismatic vertebrates, it is often assumed that these species will serve as conservation umbrellas for other species. We tested this assumption by developing a quantitative method to measure overlap in dispersal habitat of 3 threatened species—a bird (the umbrella), a butterfly, and a frog—inhabiting the same fragmented landscape. Dispersal habitat was determined with Circuitscape, which was parameterized with movement data collected for each species. Despite differences in natural history and breeding habitat, we found substantial overlap in the spatial distributions of areas important for dispersal of this suite of taxa. However, the intuitive umbrella species (the bird) did not have the highest overlap with other species in terms of the areas that supported connectivity. Nevertheless, we contend that when there are no irreconcilable differences between the dispersal habitats of species that cohabitate on the landscape, managing for umbrella species can help conserve or restore connectivity simultaneously for multiple threatened species with different habitat requirements. Definición y Evaluación del Concepto de Especie Paraguas para Conservar y Restaurar la Conectividad de Paisajes 相似文献
402.
403.
MichaelSYoung KevinMJenkins 《环境化学》2005,24(3):355-356
苯并咪唑类化合物(benzimidazoles)如涕必灵(thiabendazole)常作为杀菌剂普遍用在瓜果及农作物上.用液相色谱法分析这些物质比较困难:例如涕必灵,在硅胶基质的色谱柱上会发生严重的拖尾现象,酸性条件下尤为明显.涕必灵和多菌灵(carbendazim)在pH10的情况下使用XTerraMSC18色谱柱会得到较好的峰形,但在较高的pH值下,其它类型杀菌剂或杀虫剂可能不稳定,故难以用适合这些碱性杀菌剂的高pH值条件进行同时分析. 相似文献
404.
Philip L.Wylie 《环境化学》2002,21(2):197-200
吹扫捕集与气相色谱/质谱联用分析水中挥发性有机化合物是使用最为广泛的一种技术.取5ml水样,大多数目标化合物可在0.5μg·l-1或更低的浓度被定量.如果取25ml水样,就能得到更高的检测灵敏度.安捷伦公司吹扫捕集/气相色谱/质谱联用系统以其可靠的性能、高灵敏度和简单易用而在全球范围得到用户的认可.同时安捷伦公司可提供专为分析环境中挥发性化合物而设计的软件、消耗品及气相色谱柱,能够保证任何一间实验室得到高质量、可靠的分析实验数据. 相似文献
405.
406.
镉铅对小麦醇脱氢酶(ADH)基因表达影响的初步研究 总被引:11,自引:0,他引:11
经过镉,铅45h污染处理,运用Northein斑点杂分析和酶活性测定的方法探测萌发期小麦ADH酶基因的表达情况。实验结果表明,ADH基因表达在RNA和酶活性两个层次均有变化,并且呈现相似的变化趋势,反映得金属的影响是来源于基因转录水平。 相似文献
407.
408.
Mahmoud Marwa M. Sanad Eman F. Hamdy Nadia M. 《Environmental science and pollution research international》2021,28(28):36984-37000
Environmental Science and Pollution Research - The discovery of microRNAs (miRNAs) 20 years ago has advocated a new era of “small molecular genetics.” About 2000 miRNAs are present that... 相似文献
409.
Malki Zohair Atlam El-Sayed Ewis Ashraf Dagnew Guesh Ghoneim Osama A. Mohamed Abdallah A. Abdel-Daim Mohamed M. Gad Ibrahim 《Environmental science and pollution research international》2021,28(30):40496-40506
Environmental Science and Pollution Research - COVID-19 was first discovered in Wuhan, China in December 2019. It is one of the worst pandemics in human history. Recent studies reported that... 相似文献
410.
Denman AR Crockett RG Groves-Kirkby CJ Phillips PS Gillmore GK Woolridge AC 《Environment international》2007,33(1):34-44
Following an intensive survey of domestic radon levels in the United Kingdom (UK), the former National Radiological Protection Board (NRPB), now the Radiation Protection Division of the Health Protection Agency (HPA-RPD), established a measurement protocol and promulgated Seasonal Correction Factors applicable to the country as a whole. Radon levels in the domestic built environment are assumed to vary systematically and repeatably during the year, being generally higher in winter. The Seasonal Correction Factors therefore comprise a series of numerical multipliers, which convert a 1-month or 3-month radon concentration measurement, commencing in any month of the year, to an effective annual mean radon concentration. In a recent project undertaken to assess the utility of short-term exposures in quantifying domestic radon levels, a comparative assessment of a number of integrating detector types was undertaken, with radon levels in 34 houses on common geology monitored over a 12-month period using dose-integrating track-etch detectors exposed in pairs (one upstairs, one downstairs) at 1-month and 3-month resolution. Seasonal variability of radon concentrations departed significantly from that expected on the basis of the HPA-RPD Seasonal Correction Factor set, with year-end discontinuities at both 1-month and 3-month measurement resolutions. Following this study, monitoring with electrets was continued in four properties, with weekly radon concentration data now available for a total duration in excess of three and a half years. Analysis of this data has permitted the derivation of reliable local Seasonal Correction Factors. Overall, these are significantly lower than those recommended by HPA-RPD, but are comparable with other results from the UK and from abroad, particularly those that recognise geological diversity and are consequently prepared on a regional rather than a national basis. This finding calls into question the validity of using nationally aggregated Seasonal Correction Factors, especially for shorter exposures, and the universal applicability of these corrections is discussed in detail. 相似文献