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11.
Spatiotemporal distribution of protozooplankton and copepod nauplii in relation to the occurrence of giant jellyfish in the Yellow Sea 总被引：2，自引：0，他引：2
The occurrence of the giant jellyfish, Nemopilema nomurai, has been a frequent phenomenon in the Yellow Sea. However, the relationship between the giant jellyfish and protozoa, in particular ciliates, remains largely unknown. We investigated the distribution of nanoflagellates, ciliates, Noctiluca scintillans, and copepod nauplii along the transect 33~N in the Yellow Sea in June and August, 2012, during an occurrence of the giant jellyfish, and in October of that year when the jellyfish was absent. The organisms studied were mainly concentrated in the surface waters in summer, while in autumn they were evenly distributed in the water column. Nanoflagellate, ciliate, and copepod nauplii biomasses increased from early June to August along with jellyfish growth, the first two decreased in October, while N. scintillans biomass peaked in early June to 3 571 pg C/L and decreased in August and October. In summer, ciliate biomass greatly exceeded that of copepod nauplii （4.61-15.04 ~tg C/L vs. 0.34-0.89 pg C/L）. Ciliate production was even more important than biomass, ranging from 6.59 to 34.19 ~tg C/（L.d） in summer. Our data suggest a tight and positive association among the nano-, micro-, and meso-zooplankton in the study area. Statistical analysis revealed that the abundance and total production of ciliate as well as loricate ciliate biomass were positively correlated with giant jellyfish biomass, indicating a possible predator-prey relationship between ciliates and giant jellyfish. This is in contrast to a previous study, which reported a significant reduction in ciliate standing crops due to the mass occurrence ofN. nomurai in summer. Our study indicates that, with its high biomass and, in particular, high production ciliates might support the mass occurrence of giant jellyfish. 相似文献
12.
偏振光皮肤镜图像分析技术在临床上开发应用的研究——在皮肤肿瘤诊断中的灵敏度与特异度探讨 总被引：1，自引：1，他引：0
目的：探讨偏振光皮肤镜（DP）图像分析技术在皮肤肿瘤诊断中的价值。方法：在临床肉眼诊断的基础上,采用DP法对皮肤肿瘤进行辅助诊断,后经组织病理确诊,将诊断结果进行对照与回顾性分析。结果：总结了948例皮肤肿瘤和与其相鉴别的色素性皮损的DP法诊断指征并显示出平均灵敏度88.77%,特异度94.92%,诊断符合率达92.72%,比临床肉眼诊断符合率提高了23.94%。结论：DP法是一种无创性观察体表和表皮下部肉眼无法识别的形态学特征与数字图像技术。它对多种皮肤肿瘤尤其对色素性皮肤肿瘤的判断和良恶性皮损的鉴别诊断具有较好的辅助诊断价值。对减少盲目活检、有效指导手术切除范围和选择合理的治疗方法及术后复诊具有重要意义。 相似文献
13.
为研究温度对微型鞭毛虫（Nanoflagellates,NF）摄食细菌的影响,于广西近岸海区采集NF自然群落,置于实验室不同温度下（14℃、22℃、28℃）培养9天,观察细菌和NF的丰度变化。并以荧光细菌标记法研究不同温度下异养微型鞭毛虫（Hetertrophic Nanoflagellates,HNF）和含色素微型鞭毛虫（Pigmented Nanoflagellates,PNF）对细菌的摄食率,计算不同类型NF的群落摄食率。此外,研究还比较了不同粒径PNF （<3 μm和3~10 μm）对细菌的摄食。结果表明,不同类型的NF对细菌的摄食率由大到小为:3~10 μm PNF、HNF、小于3 μm PNF。较之PNF,HNF的摄食受温度影响较小。PNF的摄食率在22℃最大。而且,不同大小PNF的摄食对温度的响应有所不同。升温可以提高3~10 μm PNF的摄食率,但会抑制小于3 μm PNF的摄食。而降温抑制3~10 μm PNF的摄食,但降温对小于3 μm PNF摄食的抑制作用比升温小。但无论是3~10 μm PNF还是小于3 μm PNF,升温均会降低其丰度。而由于丰度减小对群落摄食率的影响更大,因此,升温降低PNF的群落摄食率。 相似文献
14.
An-Yi Tsai Gwo-Ching Gong Robert W. Sanders Ciou-Jyu Wang Kuo-Ping Chiang 《Estuarine, Coastal and Shelf Science》2010
Variation in the summer nanoflagellate community on the continental shelf ecosystem of East China Sea (ECS) is closely coupled with environmental variation due to extension of the Changjiang River plume. Spatial patterns of nanoflagellate abundance were studied in June and August 2003, June 2006 and July 2007 over the ECS shelf. The Changjiang River plume was smaller during the August 2003 and July 2007 cruises than during the rest other 2 cruises. Total nanoflagellates densities varied between 1 and 120 × 102 cells ml−1 with the highest abundances occurring within the Changjiang River plume during large plume periods. In the small plume periods, the range of nanoflagellates abundance was 3–33 × 102 cells ml−1 and the highest abundances were observed during these periods either within the Changjiang River plume or the Yellow Sea Coastal Water (YSCW). During large plume periods, nanoflagellate abundance closely related to changes in salinity and during the small period, abundance was most related to water temperature. The pigmented nanoflagellate community (PNF) within Changjiang River plume, especially in the <3 μm size class, appears to increase in response to terrestrial or anthropogenic inorganic nutrient loading in the discharge of fresh water from the Changjiang River. The PNF abundance pronounced increase caused the variation of nanoflagellate community of ECS in summer. We suggest that the discharge of fresh water from Changjiang River has significant ecological impacts on spatial variations in nanoflagellate community in the ECS. 相似文献