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排序方式: 共有128条查询结果,搜索用时 46 毫秒
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Many mainland populations of kiwi are declining because stoats (Mustela erminea) kill most of their chicks. Stoats are often trapped during conservation programmes, but the long-term effectiveness of trapping has not been measured. During continuous trapping of mammalian predators in the 9800?ha Whangarei Kiwi Sanctuary, the survival of brown kiwi (Apteryx mantelli) chicks declined over time. Following the use of sodium fluoroacetate (1080) to kill rats (Rattus spp.) and possums (Trichosurus vulpecula) and likely secondary poisoning of stoats, chick survival at Riponui increased from 5% to 56%, and the 62% chick survival at Rarewarewa was better than the 20% recorded in a trapped-only area nearby. We suggest that untrappable stoats accumulate in areas subjected to continuous predator trapping. Conservation managers should build into their long-term pest control programmes a periodic pulse of an alternative tool to kill pests that, for whatever reason, actively avoid the primary control tool. 相似文献
84.
京津冀风沙源区沙化土地治理关键技术研究与示范 总被引:2,自引:0,他引:2
京津冀风沙源区是我国北方生态屏障的重要组成部分。面向我国北方风沙区沙化土地综合治理、典型脆弱生态修复与保护等重大科技需求,京津冀风沙源区沙化土地治理关键技术研究与示范项目将综合运用长期定位观测、控制实验、多源遥感数据融合、技术示范等方法,重点研究京津冀风沙源区土地沙化形成机制与生态修复机理,研发一批沙化土地治理与产业化关键技术,并在各治理区开展试验示范,集成京津冀风沙源区沙化土地治理与产业化技术体系,构建沙化土地综合整治空间决策支持系统,为京津风沙源治理工程建设、保障京津冀地区生态安全及满足2022年北京冬奥会生态需求提供科技支撑。 相似文献
85.
S.D. HA S.D. PILLAI S.C. RICKE 《Journal of Rapid Methods and Automation in Microbiology》1995,4(1):77-85
The present study was designed to evaluate cycloheximide as a potential media amendment to prevent fungal overgrowth on selective media for salmonellae enumeration. The objectives were to determine the effect of cycloheximide on Salmonella spp growth rates and to determine the effect of cycloheximide addition on Salmonella enumeration in selective media. The bacteria tested included two strains of Salmonella typhimurium (NO/NA and LT2) and one strain of Salmonella arizonae. All strains were grown in tryptic soy broth containing cycloheximide to determine the effect of cycloheximide on bacterial specific growth rates. The growth rate of all strains grown in tryptic soy broth were not significantly influenced by addition of cycloheximide at concentrations up to 1,000 mg/L. Growth rates of S. typhimurium NO/NA in minimal media were significantly decreased by addition of cycloheximide aerobically (300 mg/L) and anaerobically (600 mg/L). However, S. typhimurium NO/NA populations on brilliant green agar, MacConkey agar, and from selenite cysteine broth and tetrathionate broth were not affected by cycloheximide additions at concentrations up to 1,000 mg/L. Cycloheximide has potential as a fungistat additive for salmonellae selective media. 相似文献
86.
Molecular phylogenetics of Stenodermatini bat genera: congruence of data from nuclear and mitochondrial DNA 总被引:2,自引:1,他引:1
Van den Bussche RA; Baker RJ; Wichman HA; Hamilton MJ 《Molecular biology and evolution》1993,10(5):944-959
Within the tribe Stenodermatini the systematics of the complex of species
allied with the genus Artibeus has generated several alternative
phylogenetic hypotheses. The most recent treatment recognized four genera
(Artibeus, Dermanura, Enchisthenes, and Koopmania) and suggested that the
most recent common ancestor of these four genera would include the common
ancestor of all other currently recognized Stenodermatini genera except
Sturnira. To test this hypothesis, we examined an EcoRI-defined nuclear
satellite DNA repeat and 402 bp of DNA sequence variation from the
mitochondrial cytochrome b gene. Phylogenetic conclusions based on Southern
blot analyses, in situ hybridization, and mitochondrial DNA sequence data
indicate that Enchisthenes is not closely related to Dermanura, Artibeus,
or Koopmania and that Dermanura, Artibeus, and Koopmania shared a common
ancestor after diverging from the remainder of the Stenodermatini. If our
conclusions are correct, then justification for recognizing Dermanura and
Koopmania as generically distinct from Artibeus must be based on the
magnitude of difference that distinguishes each rather than on the
conclusion that to place them as congeneric with Artibeus creates a
paraphyletic taxon.
相似文献
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Bud formation capacity of callus formed from thin epidermal cell loyers excised from floral branches of Nicotiana tabacum cv. Wise. 38. Subepidermal cells of thin tissue pieces with a few cell layers were capable of forming eitber buds, roots, (lowers or non-organ ogenetic callus. To determine wheiher this calltjs is able to dirferentiate into organs, we transferred it to media inducing eitber flowers, or buds, or roots. In this paper, we study ibe capacity of lbe callus to form buds. In 50% of the cases, the explants (being maintained for I day to 2 years in callus media) can still express the capacity to form buds. This percentage increased with increased agar concentration of the culture media. At the histological level, non-organogenetic callus is characterized by the absence of tracheid differentiation, whereas in the organogenetic callus, iracheids were induced after their transfer into a ‘Bud medium’ and indicate an organogenetic differentiation pattern. 相似文献
90.
T. T. T. HA M. OKABE K. MORISHIMA I. NAKAYAMA K. NAGASAWA T. UMINO 《Molecular ecology resources》2007,7(4):635-637
Multiplex polymerase chain reaction (PCR) technique has recently been applied to gain many advantages in molecular genetics. The present study focused on the development of 15 new microsatellite markers with multiplex PCR systems in ayu, Plecoglossus altivelis, an important freshwater fish in Japan. All loci were followed Mendelian inheritance in 27 F1 progeny except for the one locus. The number of alleles per locus ranged from nine to 44 and the observed heterozygosities ranged from 0.680 to 0.980 in 50 unrelated individuals. The results indicate that these new microsatellite markers are useful for studies of linkage mapping and population genetics for the species. 相似文献