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51.
【目的】分析叶蝉EST序列信息,为其分子标记体系建立、遗传图谱构建及相关致害基因挖掘奠定基础。【方法】利用生物信息学技术对NCBI数据库中的4种叶蝉亚种EST序列进行SSR基序分析与统计,并对筛选出的SSR基序区段进行引物设计,开发出SSR标记。【结果】11044条叶蝉EST序列的总长为5866kb。按照引物筛选设定的参数,筛选获得1946条含有SSR基序的EST序列,占总EST序列的17.6%;其中包含2230个SSR基序并全部获得相应的SSR引物,平均间距为2.63kb。在2~5个核苷酸重复中,3个核苷酸重复为优势基序,占总基序的77.3%,尤以AAT类最丰富,占3个核苷酸重复总数的40.7%;双核苷酸重复中,AG类所占的比例最大,为39.1%。【结论】从叶蝉EST序列中筛选获得2230个SSR引物,以3个核苷酸重复基序所占比重最大。 相似文献
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Takashi Kitagawa Shingo Kimura Hideaki Nakata Harumi Yamada 《Fisheries Oceanography》2004,13(3):161-180
Twenty‐four archival tags were recovered from Pacific bluefin tuna previously released off Tsushima Island in the East China Sea. By analysis of the time‐series data of the pressure and the ambient and internal temperature from the 24 tags, we examined the relationship between the tuna's pattern of diving and the thermocline depth. In the East China Sea, diving and feeding events occurred throughout almost the entire day in both winter and summer, suggesting that the purpose of diving is for feeding. In summer, the feeding frequency was greater than that in winter, which corresponds to the fact that growth is more rapid in summer than in winter. During summer in the Kuroshio–Oyashio transition region, on the other hand, feeding events were much more frequent than those in the East China Sea, in spite of a lower diving frequency. The mean horizontal distance traveled was also significantly higher and it seems that in this area they may move horizontally to feed on prey accumulated at the surface. We conclude that, in addition to the ambient temperature structure, the vertical and horizontal distribution of prey species plays an important role in the feeding behavior of Pacific bluefin tuna. One bluefin tuna migrated to the Oyashio frontal area, where both the horizontal and the vertical thermal gradients are much steeper. The fish spent most of the time on the warmer side of the front and often traveled horizontally to the colder side during the day, perhaps to feed. This implies that there is a thermal barrier effect, in this case from the Oyashio front, on their behavior. The frequency of feeding events was low, although all the monitored fish dived every dawn and dusk, irrespective of the seasons or location. It is possible that these twice‐daily diving patterns occurred in response to the change in ambient light at sunrise and sunset. 相似文献
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针对木材结构尺寸及介质改变对应变能传播的影响,研究应力波在变结构的L型试件中的声发射(acoustic emission,AE)特性。首先,参照ASTM-E976标准,在樟子松L型试件表面不同位置产生AE源,并利用采样频率为500 kHz的AE采集系统获取试件表面4个固定位置的AE信号。其次,依据小波分析原理对原始AE信号进行降噪并重构AE波形,进而研究木材结构变化对AE信号频域特征的影响。最后,基于对比分析,研究空气介质对于信号传播特性的影响。结果表明,当AE源位于锯材处时,信号以纵波和横波混合的形式单向传播,木材的结构变化主要影响低频信号成分,使得信号呈现高频带分布;而空气介质对于其时频域均有显著影响;当AE源位于薄板时,木材结构变化、传播路径及空气介质对于AE信号时频域特性均有显著影响。 相似文献
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The suitability of VIE tags to assess stock enhancement success in juvenile European lobsters (Homarus gammarus)
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Sarah T V Neenan David J Hodgson Tom Tregenza Dominic Boothroyd Charlie D Ellis 《Aquaculture Research》2015,46(12):2913-2923
Assessments of stock enhancement programmes for European lobsters (Homarus gammarus) require mark‐recapture analysis of stocked individuals. However, established tag technology is deemed unsuitable for extensive use by many current lobster hatcheries, particularly upon the early juvenile stages. We tested the suitability of fluorescent Visible Implant Elastomer (VIE) tags for use in 5‐month‐old juvenile lobsters. Three treatment groups comprising 348 cultured lobsters in total were used to examine survival, growth and tag retention, and to assess mobility, shelter use and moulting behaviours. Tagging had no significant effect on lobster survival, growth, mobility, shelter use or moult frequency. Survival over 7 weeks was 75% among lobsters tagged with two elastomers, 76% in those with one elastomer and 74% among untagged controls. Mortality during moulting did not increase in tagged (6%) compared to untagged lobsters (9%). We found no evidence that VIE tags cause any negative effects that would be expected to inhibit survival upon wild release, but tag loss had reached 12% in both tagged treatments after 7 weeks and showed no sign of abating. Our study suggests that VIEs effectiveness in discerning cultured lobsters long after wild release may be limited when used in smaller juveniles. 相似文献
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W. R. C. BEAUMONT S. CLOUGH M. LADLE J. S. WELTON 《Fisheries Management and Ecology》1996,3(3):201-207
Abstract An attachment technique which gives good tag retention, minimal damage to fish and prevents entanglement with weed is described. Fish carrying transmitters were monitored in semi-natural conditions and appeared to exhibit the same behaviour as untagged fish. Median condition factors of dummy-tagged fish did not differ from those of untagged fish over a 10-week period. Examples of movement patterns obtained using radio tags attached to dace, Leuciscus leuciscus (L.) are given. 相似文献
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廖朝琼 《福建农业大学学报(哲学社会科学版)》2009,(6):109-112
在《通志·乐略》中,郑樵基于当时文人对古代诗乐所取的重文学而轻音乐的态度,第一次大胆地提出了“声贵说”这一犀利观点。他从音乐与义理、文学、古题名这三方面的联系来论述,提倡诗乐应以音乐为重,以期恢复自《诗三百》以来“乐以诗为本,诗以声为用”的传统。 相似文献