Analysis of a Long-term Experiment with Repeated-measurement Models

Long‐term experiments are a classical case of repeated measurements. Traits are measured on the same experimental unit over many years so that correlations arise between the observations made on the same plot in consecutive years. This paper describes the analysis of a three‐crop‐rotation long‐term experiment. We analysed the yields of the crops and the organic carbon content in the topsoil over 30 consecutive years. Several variance–covariance approaches are discussed and the trait‐specific best fit is interpreted. Mixed models are used to describe the structure of the experiment. Both yields and soil organic carbon show a more or less pronounced variance heterogeneity. Especially for yields, the heterogeneity of cycles and years is dominant. The consideration of correlations results in a better model fit in all cases.     

MB22木聚糖酶发酵条件的研究

通过因素轮换试验和正交试验,对MB22菌产木聚糖酶的培养基配方和发酵条件进行了研究。结果显示最佳培养基组成是:以玉米芯粉和麸皮为碳源,麸皮120g/l,玉米芯280g/l,(NH4)2SO44g/l,CaCO31.5g/l,Tween80,2.0g/l,MgSO4·7H2O1.5g/l;最佳发酵条件为:起始pH5.0,摇床培养温度30℃,转速160r/min,振荡培养84h。在最佳发酵条件下,MB22菌的最高产酶活力可达898.23U/ml。虽然与一些高产菌株相比该菌株的产酶能力还有待于进一步提高,但该试验结果为进一步进行微生物生产木聚糖酶的研究提供了理论依据。     

基于正交试验的春兰分株繁殖技术优化研究

为优化春兰分株繁殖技术,以NAA为处理试剂,以兰苗成活率为评价指标,采用单因素试验、正交试验优化春兰分株繁殖影响因素。结果表明：影响因素顺序为NAA浸泡时间＞浸泡浓度＞环境温度＞光照强度＞光照时间。根据正交试验K值可得,春兰分株繁殖影响因素最优组合为NAA浸泡浓度0.3mg/L、浸泡时间15min、环境温度21℃、光照强度1000Lx、光照时间10h/d。经验证在此优化因素下,春兰分株繁殖实际成活率高达82.76%。     

海洋SOD抗疲劳作用动物实验方法初探

超氧化物歧化酶(SOD)具有防止细胞过度氧化的生理功能,从海洋生物中提取的SOD,可用于清除运动产生的自由基,起到抗疲劳作用.本文探讨了SOD抗疲劳作用的动物实验方法,为验证SOD抗疲劳效果建立技术平台.     

Long-term retention of coded wire tags in juvenile Arctic charr Salvelinus alpinus

Abstract  A hatchery experiment was organised to find out if the high loss rate of coded wire tags, noticed in connection with an Arctic charr Salvelinus alpinus (L.) restocking programme, was size-dependent and also to test head moulds for future taggings. Six moulds made by Northwest Marine Technology Inc. and five moulds made at the Finnish Game and Fisheries Research Institute were used. A total of 100 charr were tagged with standard-length coded wire tags using each mould. One-summer old charr at tagging were held for 534 days and two-summer old charr for 320 days. The tag loss rate varied between 0% and 54% and was negatively related to the size of the charr at tagging. The high loss rate was connected with the poor alignment of some moulds, such that a large proportion of the tags were located in the nasal cavity instead of the nasal cartilage. Testing of the moulds and careful grading of the fish for tagging is emphasised, especially if Arctic charr smaller than 20 g in weight are to be tagged.     

基于综合能力培养的植物生理学实践教学改革

根据植物生理学实践教学改革的目标,从强化课前预习、优化实践教学内容、革新教学方法、完善评价体系几方面阐述了植物生理学实践教学改革。     

No evidence for avoidance of black rat scent by the presumably less competitive Natal multimammate mouse in a choice experiment

In Africa, indigenous multimammate mice (Mastomys natalensis) only appear to live commensally in houses when invasive black rats (Rattus rattus) are absent, yet little is known about the underlying mechanism. Avoidance through smell may cause the absence of M. natalensis from areas occupied by R. rattus, but this hypothesis has not yet been tested. We conducted a Y-maze choice experiment where 15 M. natalensis were offered a choice between corridors containing conspecific scent, R. rattus scent and a control scent. Residence time in the R. rattus corridor was greater than that in the control corridor but equal to that in the M. natalensis corridor, suggesting that multimammate mice do not actively avoid the scent of their invasive competitor.     

伊克昭盟牧草和饲料作物应用增产菌技术的试验

199年伊克昭盟引入了牧草和饲料作物增产菌这一技术,经过7年的试验,示范及推广,至今全盟该增产菌应用面积已达4．04万hm^2,本文通过7年来在两种不同生境下,对12种牧草及作物的不同物修期采用不同方法施用增产菌,以鲜草产量和种子产量为衡量标准来探讨增产菌对不同牧草及作物的增产效果,实验结果表明：增产菌技术的应用,促进了植物的生长,使植株长高,叶面积增大,加强了光合作用,在提高鲜草产量的同时也增加了籽实的产量,具有较强的推广价值,是一项在农牧区适用的增产技术。     

中药复方催情颗粒剂的制备工艺优化

为了优化中药复方催情颗粒的制备参数,试验采用湿法制粒,通过单因素试验和正交试验优选药物与辅料及辅料间的比例、乙醇浓度和乙醇用量三个因素,通过颗粒的成型率、堆密度和休止角来评价颗粒的最佳成型工艺。结果表明,药物与辅料比为1∶1,乙醇浓度为80%,乙醇用量为(干料:乙醇)1∶0.3,制备的颗粒剂综合评分最高。中药复方催情颗粒的制备工艺优化为其临床中试试验的扩大生产提供了参考依据。     

柞蚕雄蛾浓缩液对肝细胞的保护和对高脂血症的治疗效果

为探讨柞蚕雄蛾浓缩液的保健和医用价值,分别就柞蚕雄蛾浓缩液对小鼠的保肝降酶作用和对半胱氨酸所致大鼠高脂血症的影响进行了实验。结果表明：该浓缩液可明显降低四氯化碳中毒小鼠血清中的谷丙转氨酶水平,因而能减少肝细胞变性、坏死的程度和范围,对受损伤的肝组织具有明显保护作用;可明显减轻肝组织脂肪样变性及降低由半胱氨酸所致高脂血症大鼠血清中的胆固醇、甘油三酯、低密度脂蛋白浓度,提高高密度脂蛋白浓度,因而对于高脂血症有良好的治疗效果。