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331.
为探究“十年禁渔”前沱江中游江段鱼类资源和物种多样性,于2017—2020年对该江段鱼类资源进行了8次调查,并对鱼类种类组成、生态类型、群落相似度、种群优势度、生物多样性以及群落结构稳定性等特征进行分析。结果显示,本次调查共采集鱼类87种,隶属于5目14科52属。其中,长江上游特有鱼类18种,外来物种6种,分别占总种类数的20.69%和6.90%。鱼类群落以底层、缓流型、产沉性卵、杂食性鱼类为主。相对重要性指数(IRI)显示,蛇、鲤等中小型鱼类为优势种。Shannon-Wiener指数、Simpson指数、Margalef指数、Pielou指数变化范围分别为2.700~3.742、0.873~0.968、5.374~11.323、0.737~0.887,表明沱江中游鱼类群落分布均匀。等级聚类分析 (Cluster)和非度量多维尺度分析 (NMDS)显示,在一定的相似性水平上,沱江中游江段鱼类的群落类型基本可分为3组,莲花山、麻柳坝工业园与铁路沟可以聚为一组,万古庙、五里店水电站、资州大桥、银山镇、二水厂与西林渡口聚为一组,沱桥独立成组。数量/生物量比较曲线分析结果显示,西林渡口和沱桥江段鱼类群落结构稳定性相对较高,其余江段鱼类群落结构均受到中度干扰。研究表明,与历史资料相比,沱江中游鱼类群落发生了显著变化,经济鱼类占比减少,鱼类个体呈现小型化和低龄化。本研究补充了沱江中游鱼类资源现状的基础数据,以期为该江段鱼类资源管理与“十年禁渔”生态评估提供科学依据。 相似文献
332.
GUAN Yu-yu LIAO Rong-rong WANG Zhen ZHAO Jing CHEN Zhen-liang ZHANG Zhe XIAO Qian SUN Hao WANG Qi-shan ZHANG Xiang-zhe YANG Chang-suo PAN Yu-chun 《中国畜牧兽医》2016,43(6):1413-1421
The study was conducted to explore the potential different characters between Blue-shelled chicken and White leghorn.Global genome microRNA was combined the identified microRNA with complementary lab-predicted microRNA.Then the two breed chicken's SNP data got by GGRS were mapped to the microRNA and focused on SNP that deliberately located in mature-microRNA.Bioinformatics method was adopted for target prediction on microRNA which had SNPs.By further gene enrichment analysis,the study found these genes enriched in 22 GO terms,10 KEGG pathways,and 3 IPA important networks.And they enriched in traits which associated with growth,such as mTOR signaling pathways,Wnt signaling pathways,growth hormone receptor networks and insulin-like growth factor Ⅰ receptor networks.And they also enriched in some laying traits,such as oocyte meiotic signaling pathways and progesterone mature oocytes signaling pathways.The methods and the results might provide references for further studies. 相似文献
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Protective effects of antioxidant additives of selenium and vitamin E on rats that consumed maize naturally contaminated with
mycotoxins were explored in this paper. Thirty-two Wistar female rats were randomly divided into four groups. The control
group was given the basic diet with normal maize. The contaminated maize group was given the diet in which normal maize was
replaced by mycotoxin-contaminated maize. The selenium group and vitamin E group were respectively fed mycotoxincontaminated
diet supplemented with 0.4mg · kg−1 selenium from yeast or 100 mg · kg−1 vitamin E. The trial lasted for 4 weeks. Compared with the control group, antioxidative status was decreased significantly
in the contaminated maize group. However, the status in the selenium group and vitamin E group was increased significantly
compared with the contaminated maize group. The activities of enzymes related to liver function were significantly higher
in the contaminated maize group than those in the control group, whereas they were significantly lower in the selenium group
and/or the vitamin E group compared to the contaminated maize group. It is concluded that selenium and vitamin E were able
to alleviate oxidative stress and liver function damage due to the consumption of maize naturally contaminated with mycotoxins. 相似文献
335.
Xie Weimin Wang Qunhui Yao Jie Ma Hongzhi Ohsumi Yukihide Ogawa Hiroaki I. 《Water, air, and soil pollution》2004,159(1):313-324
The adsorption of a fixed bed filled with bone char was investigated in terms of its efficiency and capacity by determining operational conditions for the purpose of further reduction of organic matter and removal of phosphorus using a continuous flow of real secondary effluent. Simultaneous removals of phosphorus and chemical oxygen demand (COD) were sufficiently achieved by this fixed-bed method. Stable performance was maintained even at a linear flow velocity (abbreviated as LV) of 1.5 m h–1. Appropriate backwashing and regeneration were required to operate the system continuously for a long period of time. During the regeneration, the use of treated water including Ca2+ ion was so effective that phosphorus removal efficiency increased from about 50 to 80%, and afterwards maintained over 65%, until inflow water of the volume up to 150 times as large as the volume of bone char had passed through. Even when the inflow water of the volume rose up to 200 times, the phosphorus removal efficiency could be maintained over 50%. During this operation, the adsorptions of phosphorus and COD onto the bone char surface were observed to be over 6.7 and 35 gL–1, respectively. 相似文献
336.
极度濒危植物--崖柏种群空间格局与动态的初步研究 总被引:7,自引:1,他引:7
通过对开县境内4个典型崖柏种群空间分布格局进行初步研究,表明崖柏种群为明显的集群分布,在取样尺度较小时(群落Ⅰ、Ⅲ、Ⅳ为4m^2;群落Ⅱ为6m^2)集群强度最大,且随着取样尺度的扩大聚集强度逐渐减小。在各群落中集群强度以多齿长尾槭一崖柏群落(Ⅰ)最大,依次为崖柏一铁杉群落(Ⅱ),崖柏-巴东栎群落(Ⅲ),崖柏-黄杨群落(Ⅳ)最小。在对崖柏初步研究的基础上还提出了进一步研究的方向。 相似文献
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犬蠕形螨病是由蠕形螨寄生于犬皮脂腺或毛囊而引起的一种顽固性寄生虫性皮炎。本病的发生多是真菌细菌和蠕形螨的混合感染,一般治疗顺序是先杀细菌和真菌,然后再除螨,通过症状与实验诊断的方法诊出的病犬31只,用伊维菌素和辅助“二合一”,“抗真菌Ⅰ号”外洗综合治疗方法,痊愈28只,治疗效率很好。 相似文献
340.
基因工程菌株里氏木霉(Trichodermareesei)生物合成的组织型纤溶酶原激活剂(tissue-typeplasminogenactivator,t-PA)经分离纯化后,采用还原SDS-PAGE和非还原PAGE分析达到了电泳纯,采用Superdex75PrepGrade凝胶过滤色谱分析达到了色谱纯;采用还原SDS-PAGE分析其相对分子质量为6.6×104,SDS-聚丙烯酰胺凝胶电泳纤维蛋白自显影法检测其相对分子质量为6.6×104,与相关文献报道的一致。等电聚焦电泳测定其等电点为4.24。 相似文献