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261.
Indicator Species and Scale of Observation 总被引:2,自引:0,他引:2
Jan C. Weaver 《Conservation biology》1995,9(4):939-942
262.
263.
Peter Witzgall Jean-Pierre Chambon Marie Bengtsson C. Rikard Unelius Monica Appelgren Gyorgy Makranczy N. Muraleedharan Darwin W. Reed Klaus Hellrigl Hans-Ruedi Buser Eric Hallberg Gunnar Bergström Miklos Tóth Christer Löfstedt Jan Löfqvist 《Chemoecology》1996,7(1):13-23
Summary The geometric isomers (E,E)-, (E,Z)-, (Z,E)-, and (Z,Z)-8,10-dodecadien-1-yl acetate were identified as sex pheromone components or sex attractants in the tribes Eucosmini and Grapholitini of the tortricid subfamily Olethreutinae. Species belonging to the more ancestral Tortricinae were not attracted. Each one isomer was behaviourally active in males ofCydia andGrapholita (Grapholitini), either as main pheromone compound, attraction synergist or attraction inhibitor. Their reciprocal attractive/antagonistic activity in a number of species enables specific communication with these four compounds.Pammene, as well as otherGrapholita andCydia responded to the monoenic 8- or 10-dodecen-1-yl acetates. Of the tribes Olethreutini and Eucosmini,Hedya, Epiblema, Eucosma, andNotocelia trimaculana were also attracted to 8,10-dodecadien-1-yl acetates, but several otherNotocelia to 10,12-tetradecadien-1-yl acetates. The female sex pheromones ofC. fagiglandana, C. pyrivora, C. splendana, Epiblema foenella andNotocelia roborana were identified. (E,E)- and (E,Z)-8,10-dodecadien-1-yl acetate are producedvia a commonE9 desaturation pathway inC. splendana. CallingC. nigricana andC. fagiglandana females are attracted to wingfanning males. 相似文献
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265.
基于费米能级差,构建了以BiVO_4为光阳极,Cu_2O/CuO为光阴极的双光电极可见光响应光催化燃料电池体系,研究了该体系在不同氧化剂的辅助作用下光电催化降解苯酚的效率与动力学.结果表明,向该体系中投加H_2O_2可以显著促进苯酚的降解,且反应过程光电流稳定,铜溶出量低.详细探究了H_2O_2初始浓度、pH对降解的影响,结果表明在H_2O_2投加量为5 mmol·L~(-1),初始pH为3.5条件下利于苯酚降解,5 mg·L~(-1)的苯酚可在120 min内完全去除.顺磁共振和猝灭实验表明该体系的主要氧化物种为·OH、·O~-_2和光生空穴.该催化体系实现了苯酚在可见光下的高效催化降解. 相似文献
266.
Hanneke J. Nijland Noelle M. C. Aarts Reint Jan Renes 《Journal of Agricultural and Environmental Ethics》2013,26(3):523-535
The results of an empirical study into the perceptions of “hands-on” experts concerning the welfare of (non-human) animals in traveling circuses in the Netherlands are presented. A qualitative approach, based on in-depth conversations with trainers/performers, former trainers/performers, veterinarians, and an owner of an animal shelter, conveyed several patterns in the contextual construction of perceptions and the use of dissonance reduction strategies. Perceptions were analyzed with the help of the Symbolic Convergence Theory and the model of the frame of reference, consisting of knowledge, convictions, values, norms, and interests. The study shows that the debate regarding animals in circuses in the Netherlands is centered on the level of welfare that is required; the importance of animal welfare is not disputed. Arguments that were used differed according to the respondents’ specific backgrounds and can be placed on a gradient ranging from the conviction that the welfare of animals in circuses is sufficiently warranted and both human and animal enjoy the performance (right end), to the conviction that animal welfare in circuses is negative, combined with the idea that the goal of entertaining people does not outweigh that (left end). The study confirms that perceptions reflect people’s contexts, though the variety in scopes suggests that the (inter)relations between people and their context are complex in nature. Evidence of cognitive dissonance was abundant. Coping strategies were found to be used more by respondents towards the right end of the gradient, suggesting that those respondents experience more ambivalence. This encountered pattern of association between position on the gradient and frequency of dissonance reduction strategies calls for further research on the type of ambivalent feelings experienced. The authors argue that, to come to an agreement about the welfare of animals in circuses, including the way this welfare should be guaranteed, stakeholders from different contexts need to engage in a dialogue in which a distance is taken from right/wrong-schemes and that starts from acceptance of dilemmas and ambiguity. 相似文献
267.
Freek S. Mandema Joost M. Tinbergen Bruno J. Ens Jan P. Bakker 《Journal of Coastal Conservation》2013,17(3):409-416
The purpose of this study is to experimentally determine the differences between four grazing treatments on the trampling of nests. Additionally, we examine to what extent the trampling probability of nests is higher close to a source of fresh water. We compare the trampling of artificial nests in five different grazing treatments in an experimental design. We use buried clay pigeon targets as artificial mimics of bird nests to obtain reliable estimates of trampling risk and compare these with real nests. We find that horses trample significantly more artificial nests than cattle resulting in lower survival rates of artificial nests under horse grazing than under cattle grazing. For both horses and cattle, we find a clear trend, approaching significance, towards more trampling at higher numbers of livestock. We found that more artificial nests are trampled closer to a freshwater tank. The survival probability of artificial nests in cattle grazed treatments in this study is found to be in the same range as real nests in the study area and very close to the survival probability of Northern Lapwing (Vanellus vanellus) nests under cattle grazing in a different system. We recommend that horses should not be used as grazers for management purposes in areas with high densities of birds’ nests in order to minimize the risk of nests being trampled. Additionally, we confirm that the location of freshwater tanks has an important effect on the distribution of livestock and hence on trampling of nests. 相似文献
268.
Population genetics of Crassostrea ariakensis in Asia inferred from microsatellite markers 总被引:1,自引:0,他引:1
Jie Xiao Jan F. Cordes Haiyan Wang Ximing Guo Kimberly S. Reece 《Marine Biology》2010,157(8):1767-1781
Crassostrea ariakensis is an important aquacultured oyster species in Asia, its native region. During the past decade, consideration was given to
introducing C. ariakensis into Chesapeake Bay, in the United States, to help revive the declining native oyster industry and bolster the local ecosystem.
Little is known about the ecology and biology of this species in Asia due to confusion with nomenclature and difficulty in
accurately identifying the species of wild populations in their natural environment. Even less research has been done on the
population genetics of native populations of C. ariakensis in Asia. We examined the magnitude and pattern of genetic differentiation among 10 wild populations of C. ariakensis from its confirmed distribution range using eight polymorphic microsatellite markers. Results showed a small but significant
global θ
ST (0.018), indicating genetic heterogeneity among populations. Eight genetically distinct populations were further distinguished
based on population pairwise θ
ST comparisons, including one in Japan, four in China, and three populations along the coast of South Korea. A significant positive
association was detected between genetic and geographic distances among populations, suggesting a genetic pattern of isolation
by distance. This research represents a novel observation on wild genetic population structuring in a coastal bivalve species
along the coast of the northwest Pacific. 相似文献
269.
Jiří Kopáček Jan Turek Josef Hejzlar Hana Šantrůčková 《Atmospheric environment (Oxford, England : 1994)》2009,43(34):5443-5453
Precipitation and throughfall fluxes of major ions, nutrients (C, N, P), and metals (Al, Fe, Mn), and the chemical composition of litter fall and living plant tissue in Norway spruce stands (the Bohemian Forest; Czech Republic), were used to evaluate how microbial processes and decay of plant tissue in canopies influence canopy leaching (CL) of elements. Proton exchange for Mg2+, Ca2+, and K+ in decaying biomass and co-transport of Ca2+ and K+ out of plant cells with organic acid anions were the most likely processes contributing to CL of base cations. The CL of total P and N (and also NO3?) was minor. Important proportions of the N and P mineral forms were transformed to organic forms by microbial processes (primary and bacterial production), with the respective CL of ?13.9 and 16.4 mmol m?2 yr?1 for NH4+ and organic N, and ?0.33 and 0.22 mmol m?2 yr?1 for dissolved reactive P (DRP) and organic P. Most of particulate P and N in throughfall (~90%) originated from microbial DRP and NH4+ transformations, but particulate C mostly came from the fragmentation of plant tissue (58%). Among metals, CL was not observed for Al, was small for Fe (0.3 mmol m?2 yr?1), and greatest for Mn (0.9 mmol m?2 yr?1) due to leaching from decaying tissue by acidic precipitation. 相似文献
270.
Phosphorus flows in Swedish agriculture and food chain were studied by material flow analysis. The system studied included agriculture, food consumption, related waste and wastewater from private households and municipal wastewater treatment plants. Swedish farmland had net annual phosphorus inputs of ~12 600 metric tons (4.1 kg P ha−1) in 2008–2010. The total import of phosphorus in food and feed to Sweden exceed imports of phosphorus in fertilizers. Despite strict animal density regulations relating to manure phosphorus content, phosphorus is accumulating on Swedish animal farms. The total quantity of manure produced greatly exceeds imported mineral phosphorus fertilizer and almost equals total phosphorus inputs to Swedish farmland. 相似文献