家蚕新突变型体节畸形(mbs)的形态学研究

家蚕新的体型自然突变型——体节畸形(body segment moster,基因记号mbs),其形态特征与其他遗传性畸形蚕显著不同.幼虫以第8～10体节前后愈合形成畸形为主,不同个体在第2～11体节上一处或多处、2～3个环节或更多个环节发生畸形,在蚕体背面形成程度不同的瘤状突起和愈合痕,并引起体形扭曲、短缩及腹肢缺少或错位、个别有过剩尾角等.本研究系统调查描述了此突变型幼虫、蛹、蛾及胚胎的畸形性状,摄制了相应的形态图片,并调查了历代群体发生畸形蚕的比例,与其他畸形蚕进行了形态上的比较.     

Assembling a physical map of the genome by marker sequences

lntroductionAfteragenomehasbeenfragmented,thefrag-mentsclonedtogenerateagen0miclibrary.ltisnecessaryt0assemblethecIonedfragmentsinthesameIinearorderasfoundinthechromos0mesfromwhichtheyarederived.OnemethodofIinkingcIonedfragmentswaschromosomewalking(Benderetal.1983),whichwasoriginaIlydevelopedfOrtheis0Iationofgenesequenceswhosefunctionwasunknownbutwhosegeneticlocationwasknown.Forthepurposesofmapping,asinglecIonedfragmentwasseIectedandusedasapr0betodetectotherclonesintheIibrary,withwhichthep…     

薄层光谱电化学的研究

The formal potentials and the numbers of electron transferred of the redox systems of Fe(CN)_6~(3-)/Fe(CN)_6~(4-) and methylene blue were determined with a Long-Path Length Thin-Layer spectroelectrochemical cell. The results obtained from our experiments     

高等级公路路线设计中缓和曲线采用长度的研究

本文对高等级公路设计中经常遇到的缓和曲线采用长度问题,根据国内外高等级公路设计的新概念,从理论和实践上进行了阐述,对提高公路的设计水平提出具体意见。     

Estimation of individual leaf area,fresh weight,and dry weight of hydroponically grown cucumbers (Cucumis sativus L.) using leaf length,width, and SPAD value

Non-destructive and mathematical approaches of modeling can be very convenient and useful for plant growth estimation. To predict individual leaf area, fresh weight, and dry weight of a cucumber (Cucumis sativus L.), models were developed using leaf length, leaf width, SPAD value, and different combinations of these variables. Eight regression equations, commonly used for developing growth models, were compared for accuracy and adaptability. The three nonlinear models developed were as follows: individual leaf area (LA) = −210.61 + 13.358W + 0.5356LW (R² = 0.980^***), fresh weight (FW) = −2.72 + 0.0135LW + 0.00022LWS (R² = 0.956^***), and dry weight (DW) = 0.25 − 0.00102LS + 0.000077LWS (R² = 0.956^***), where L is the leaf length, W the leaf width, S the SPAD value, and LWS = L × W × S. For validation of the model, estimated values for individual leaf area, fresh weight, and dry weight showed strong agreement with the measured values, respectively. Leaf dry weight, especially, was estimated with a higher degree of accuracy through the use of a SPAD value, as well as leaf length and width. Therefore, it is concluded that models presented herein may be useful for the estimation of the individual leaf area, fresh weight, and dry weight of a cucumber with a high degree of accuracy.     

Effect of paclobutrazol,prohexadione-Ca,deficit irrigation,summer pruning and root pruning on shoot growth,yield, and return bloom,in a ‘Blanquilla’ pear orchard

During the period 2001–2003 the performance of paclobutrazol, prohexadione-Ca, root pruning, summer pruning and deficit irrigation was studied with respect to a control in a Blanquilla pear orchard. Shoot growth, yield, fruit size, and return bloom were all evaluated.     

不同剂量半胱胺对东北细毛羊生产性能影响的研究

本试验采用东北细毛羊羔羊32只，均为雌性，随机分成4组，其中一组为对照组，饲喂基础日粮，其余3组分别在日粮中添加半胱胺75、125、175 mg/kg。试验结果表明，添加125 mg/kg的试验组最佳，使羔羊平均日增重提高20.96%（P≤0.01），平均毛长增长提高31.51%（P≤0.01），料肉比降低15.79%（P≤0.01），平均日收入提高66.07%（P≤0.01）。     

Influence of MHS genotype and feeding regime on allometric and temporal growth of pigs assessed by magnetic resonance imaging

A total of 68 barrows, 4-way-crosses with a Piétrain × Hampshire sire and a Large White × German Landrace dam were used in this study. The pigs were divided into 4 groups regarding the MHS (malignant hyperthermia syndrome) genotype (NN and Nn) and feeding regime (intensive and restrictive). The piglets were genotyped by DNA test; data on muscle and fat growth were obtained by repeated measurements of body composition at 4 weeks intervals by magnetic resonance imaging (MRI). Differential growth analysis showed that muscle tissue grew proportionally with the increase of live weight (allometric coefficient, b ≈ 1); fat grew faster in relation to live weight (b > 1) in all investigated groups of pigs. Significant differences in growth coefficients for fat were found only between feeding groups. The analysis by asymmetric S-function showed different patterns of live weight growth of pigs from two feeding regimes. Within the feeding regimes, no significant differences in live weight growth patterns between the pigs of different MHS genotype (NN and Nn) were found. Muscle growth pattern significantly differed between the groups of investigated pigs: Nn pigs from the intensive feeding group were significantly superior to NN pigs in the same group and to Nn pigs fed restrictively (p < 0.05), but only in the phase of progressive growth (b-coefficient of the S-function). In this respect Nn pigs performed better under intensive feeding than under restrictive feeding regime, while no difference was found between NN pigs from two feeding regimes. By combining information on live weight and muscle growth, the optimal slaughter weight of pigs was calculated: 130 and 126 kg for intensively fed NN and Nn pigs, respectively, and about 114 kg for both genotypes from the restricted group of pigs. From fat growth analysis by asymmetric S-function, no influence of genotype on fat deposition in both feeding systems could be observed. Growth patterns of fat differed significantly only between the feeding groups. This study showed that the growth of body components fits a sigmoid curve and that the asymmetric S-function proved to be a more accurate and informative model than a simple allometric function, providing a base for important decisions in fattening of pigs. A practical consequence of this study is that the more cost-effective restrictive feeding regime can be recommended as more appropriate in fattening of pigs, since intensive feeding generally failed to improve their growth traits. Similarly, inclusion of MHS-gene did not enhance muscle growth characteristics of investigated pigs, so MHS-negative pigs (NN) can be considered as more desirable fatteners, especially when fed restrictively.     

活性氧(ROS)对小鼠早期胚胎染色体相对长度的影响

通过对小鼠体内发育的囊胚、扩张囊胚和从1-细胞期取出在CZB培养液中培养的囊胚、扩张囊胚的染色体相对长度进行统计分析,在各号染色体相对长度出现显著性差异的同时,发现体外培养的比体内发育的染色体相对长度短;体外CZB培养的不同时期添加外源性过氧化氢,发育至囊胚、扩张囊胚阶段,制作胚胎标本,观察胚胎的染色体相对长度。结果表明:不同时期添加外源性过氧化氢组比对照组的染色体相对长度短。说明经过氧化氢处理之后存活下来的胚胎染色体相对长度发生了变化。     

复州牛成年母牛体重与体尺指标的相关与回归分析

以辽宁省两个复州牛保种场104头母牛2004年体尺数据为基础材料,对复州牛体重与年龄、体长、体高、胸围、管围的相关系数进行了分析,同时建立了估测复州牛成年母牛体重的回归模型。结果表明:复州牛体重与体高、体长、胸围、管围、年龄之间的相关系数分别为0．798、0．644、0．678、—0．167、0．406,经检验,除管围与体重的相关系数不显著外(P＞0．05),其它四个相关系数均达到极显著水平(P＜0．01);两个估测体重的回归模型估测值与实测值之间的相关程度分别为0．923和0．922,达到极显著水平(P＜0．01)。