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为了实现由应试教育向素质教育的转变 ,适应现代社会对高素质人才的需要 ,必须加强素质教育 ,而实现素质教育的核心问题是提高课堂教学质量 ,因此 ,创设最优化课堂教学、促进学生个性健康发展和素质的全面提高是极其必要的。本文拟就这一问题 ,举《淡水生物学》教学中之例 ,谈谈粗浅的“五字法”。一、精指授课“精”和板书“精”。1、授课“精”。教师讲课时照本宣科 ,会使学生无所适从 ,觉得枯燥乏味 ,甚至于“丢了西瓜 ,拣了芝麻”。因此 ,教师应深入钻研教材 ,挖掘课程体系 ,找出每章、每节课的难点和重点 ,分清轻重、强弱 ,强化重点和… 相似文献
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罗非鱼 MC4R 基因克隆及与其生长相关的 SNPs 位点 总被引：4，自引：2，他引：2
黑素皮质素受体-4(Melanocortin receptor-4,MC4R)是5种已发现的黑素皮质素受体家族成员之一,属于跨膜G-蛋白耦联受体超级家族,对于调节动物的采食量、体质量及能最稳态有着重要的作用.本研究采用基因组步移技术获得了尼罗罗非鱼(Oreochromis niloticus)MC4R基因组DNA序列.该基因全长2547 hp,其中5'侧翼序列长为1481 bp,3'侧翼序列长为82 bp,编码区序列长为984 bp,只有1个外显子.采用PCR产物直接测序法、PCR-RFL和CRS-PCR技术对尼罗罗非鱼MC4R基因启动子和外显子区域进行了SNPs位点的检测和分犁,结果共检测到5个SNPs位点(-G1000C、-T974A、C276T、C561T和C708T),其中外显子上的3个SNPs位点均为同义突变.利用一般线性模型分析5个SNPs位点与尼罗罗非鱼生长性状的关系,结果表明,5个SNPs位点不同基因型之间体质量均值差异最大值分别为9.5%、23.2%、14.4%、18.6%和13.5%,没有达到显著水平(P＞0.05).将5个SNPs位点不同基因型组合成7种双倍型(去掉频率小于3%的组合),关联分析表明,在体质量和体长这2个主要生长性状方面,双倍型D4与D1、D3、D6存在显著性差异(P＜0.05),双倍型D2与D3、D6也存在显著性差异(P＜0.05).因而可以考虑将MC4R基因作为影响罗非鱼体质量等生长性状的候选基因,应用于罗非鱼分子标记辅助育种. 相似文献
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Sergey Menzikov 《Fish physiology and biochemistry》2018,44(2):583-597
This paper presents a comparative study of the roles of Cl? and HCO3 ? in the functioning of the GABAAR-associated Cl?/HCO3 ?-ATPase of the plasma membranes of the olfactory sensory neurons (OSNs) and mature brain neurons (MBNs) of fish. The ATPase activity of OSNs and its dephosphorylation were increased twofold by Cl?(15–30 mmol l?1), whereas the enzyme from MBNs was not significantly affected by Cl?. By contrast, HCO3 ?(15–30 mmol l?1) significantly activated the MBN enzyme and its dephosphorylation, but had no effect on the OSN ATPase. The maximum ATPase activity and protein dephosphorylation was observed in the presence of both Cl?(15 mmol l?1)/HCO3 ?(27 mmol l?1) and these activities were inhibited in the presence of picrotoxin (100 μmol l?1), bumetanide (150 μmol l?1), and DIDS (1000 μmol l?1). SDS-PAGE revealed that ATPases purified from the neuronal membrane have a subunit with molecular mass of ~?56 kDa that binds [3H]muscimol and [3H]flunitrazepam. Direct phosphorylation of the enzymes in the presence of ATP-γ-32P and Mg2+, as well as Cl?/HCO3 ? sensitive dephosphorylation, is also associated with this 56 kDa peptide. Both preparations also showed one subunit with molecular mass 56 kDa that was immunoreactive with GABAAR β3 subunit. The use of a fluorescent dye for Cl? demonstrated that HCO3 ?(27 mmol l?1) causes a twofold increase in Cl? influx into proteoliposomes containing reconstituted ATPases from MBNs, but HCO3 ? had no effect on the reconstituted enzyme from OSNs. These data are the first to demonstrate a differential effect of Cl? and HCO3 ? in the regulation of the Cl?/HCO3 ?-ATPases functioning in neurons with different specializations. 相似文献
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团头鲂 HSP70 cDNA 的克隆、序列分析以及热应激对其 mRNA 表达的影响 总被引：2，自引：0，他引：2
采用RT-PCR和cDNA末端快速扩增法(RACE)分离、克隆出团头鲂(Megalobrama amblycephala)肝脏热休克蛋白70(HSP70)基因全长cDNA序列,共2 224 bp,包括135 bp5'非翻译区、1 932 bp阅读框以及157 bp 3'非翻泽区[不包括Poly(A)].阅读框共编码643个氨基酸,分子量计算值为70.53 kD,理论等电点为5.25.该HSP70基因在翻译区不含内含子,符合诱导型HSP70的特征.团头鲂HSP70氨基酸序列中含有HSP70家族的3个签名序列以及细胞质特异性调控基序EEVD等.同源性分析表明,团头鲂HSP70氨基酸序列与斑马鱼等脊椎动物的相似性高达84.0%以上,与无脊椎动物果蝇的相似性也高达73.4%.生物信息学分析显示,团头鲂HSPTO基因所编码的蛋白质以亲水性区域为主,具有丰富的B细胞抗原位点,无信号肽,无跨膜区域,为非分泌型蛋白;同时还含有众多的蛋白激酶C磷酸化位点、N-肉豆蔻酰化位点、酪蛋白激酶Ⅱ磷酸化位点和N-糖基化位点,推测其可能在细胞信号转导与调控中发挥重要作用.该蛋白含有2个部分重叠的双向核定位序列,二级结构以α-螺旋和无规卷曲为主,空间结构包括N端ATPase功能域和C端多肽结合功能域.应用实时定量PCR研究高温(34℃)应激对团头鲂HSP70 mRNA表达的影响.结果表明,在热应激过程巾肝脏HSP70 mRNA水平呈先升高后下降的变化趋势,说明该基因的表达受热应激调控,本实验克隆的序列为诱导型HSP70 cDNA. 相似文献
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2010年11月22日召开的广东省淡水渔业作会议提出了“十二五”发展目标：力争到2015年，全省淡水渔业综合实力显著提升，总产量达到360万吨；总产值达450亿元，产业结构得到优化，区域布局更趋合理， 相似文献
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深加工企业屈指可数近来年，随着罗非鱼产业的变化发展，下脚料深加工技术越来越受到行业的关注。广东省内部分先知先觉的罗非鱼加工企业（如五丰、国溢旗下的中南岛等）逐步认识到，依靠粗加工罗非鱼片出口的传统模式已经不能满足愈发激烈的国际市场竞争的需求。而进行下脚料深加工不仅成为他们进一步赢得市场优势的不二选择，更是罗非鱼产业发展的必然方向。 相似文献
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Paiboon Panase Bunyanuch Kamee Sakditad Moungmor Prameda Tipdacho Jaturong Matidtor Nantaporn Sutthi 《Fisheries Science》2018,84(6):1025-1036
This study was conducted to evaluate the effects of Euphorbia hirta leaf extract on the growth performance, hematological and organosomatic indices of hybrid catfish, Clarias macrocephalus?×?C. gariepinus. The fish were treated with 0 (control), 300, 500 and 800 mg/kg (ppm) for 90 days. The weight gain, average daily growth rate, and specific growth rate were at significantly higher levels in fish from all the treatment groups on days 75 and 90, while the feed efficiency and protein efficiency ratio were consistently higher in fish from all the treatment groups from day 60 up until day 90. The feed conversion rate significantly decreased from day 60 until day 90 in all treatment groups when compared with the control group, and the survival rate was significantly different from day 30 until day 90; a consistently higher rate was observed in fish fed 800 mg/kg. The highest viscerosomatic index and intraperitoneal fat were observed in the group fed 500 mg/kg (p?<?0.05). The hepatosomatic index was significantly increased alongside increasing levels of E. hirta extract. The total white blood cell count in the control group was significantly higher on day 30, but on day 90 all the treatment groups showed higher levels. Hematocrit percentage was significantly different on days 30 and 90. Lymphocyte, eosinophil and thrombocyte levels were shown to be significantly different (p?<?0.05) when different groups of fish were compared. In conclusion, 300 mg/kg of E. hirta leaf extract could improve growth performance, hematological and some organosomatic indices in hybrid catfish. 相似文献