鸭的类似鸡白细胞介素2基因的克隆及遗传进化分析

通过RT—PCR和DNA测序技术，克隆和测定了绍兴麻鸭的一种类似鸡白细胞介素2(IL-2)基因的核苷酸序列，并构建了该基因编码蛋白的三维结构分子模型。结果显示，绍兴麻鸭的类似于鸡IL-2基因的核苷酸长度由748个碱基组成，编码产物为由140个氨基酸残基组成的多肽，编码产物中含有21个氨基酸残基组成的信号肽。绍兴麻鸭的类似于鸡IL-2基因的核苷酸及编码产物，与鸡和火鸡IL-2的一致性分别为71.4％～72．1％和55．0％～57．9％，与哺乳类等动物IL-2的一致性分别为22．1％～28．8％和14．3％～17．1％。对绍兴麻鸭的类似于鸡IL-2基因蛋白编码产物的系统进化树分析表明，其编码产物与鸡和火鸡IL-2具有较远的亲缘关系。绍兴麻鸭的类似于鸡IL-2基因编码产物的三维结构，预测由4个α-螺旋结构和2个β折叠组成。这些研究结果预示。鸭的类似于鸡IL-2基因编码产物，在生物学功能上与哺乳动物和其他禽类具有很大的差异。     

荔枝冷害过程中果皮色泽、花色素苷和类黄酮含量的变化

 研究了‘糯米糍’荔枝果实在3 ℃和0 ℃条件下果皮的色泽和花色素苷及类黄酮含量的变化。结果表明, 果实在0 ℃下14 d 时褐变指数迅速增大, 21 d 时已遭受不可逆的冷害。在冷藏过程中, 果皮的色泽指标a、L、C 值及花色素苷、类黄酮、总酚含量均随贮藏时间的延长而下降, 0 ℃下比3 ℃下降快。0 ℃下14～21 d , a、L、C 值分别下降了27.95 %、33.58 %和58.47 % , 而21 d 时果皮花色素苷、类黄酮和总酚含量依次为采收时的18.08 %、35.99 %和41.64 %。说明冷害加速了荔枝果皮花色素苷的降解及类黄酮和总酚的变化, 促进了褐变进程的发生。果皮a、L、C 值与褐变指数、花色素苷含量呈显著相关性( P < 0.05) ,采用自动测色色度计可真实地反映果皮花色素苷含量和褐变程度。     

紫花苜蓿的栽培与利用

紫花苜蓿为多年生豆科牧草,其根系发达,入土深,再生能力强,分枝多,枝叶茂盛,营养丰富,粗蛋白含量高,耐瘠耐旱,抗寒,生物学价值高,有“牧草之王”的美称,是目前养殖畜禽的优质饲草,同时亦是肥田、固土、保水的理想植被。我市自2000年引入栽培以来,分别在不同的海拔、熟地、退耕地进行单作、套作、间作,其适应性良好,种植效益显著,种植面积迅速扩大,目前种植面积已达1000hm2(公倾)以上,深受养殖农户的喜爱。现将其种植、利用的基本技术简介于后,以供参考。1栽培要求1.1品种选择紫花苜蓿品种繁多,其适应性与品种有较大相关,选择好品种是苜蓿种…     

J亚群禽白血病病毒与禽网状内皮增生症病毒共感染对肉鸡生长和免疫功能的抑制作用

1日龄网鸡感染J亚群禽白血病病毒(ALV-J)以及共感染禽网状内皮增生症病毒(REV)后,肉鸡生长发育明显受阻,体重增重明显下降(P＜0.05),法氏囊、胸腺明显萎缩(P＜0.05),在用新城疫疫苗免疫后,感染组血清中新城疫抗体效价显著低于对照组(P＜0.05);在ALV-J和REV共感染后,这种抑制作用更为明显(P＜0.01).ALV J单独感染后,鸡对传染性法氏囊病病毒(IBDV)弱毒疫苗免疫后的抗体反应与对照组没有明显差别,但ALV-J与REV的共感染可明显延缓鸡对IBDV弱毒疫苗免疫的抗体反应.     

crataegus grayana的组织培养

同许多种其它果树一样,山植属的Crataegus grayana也可应用组织培养的方法,进行快速繁殖。在加入0.25ppmBA,0.5ppmIAA以及150ppm水解干酪素的MS培养基上,可由胚得到实生苗。在加入0.5ppm和300ppm水解干酪素的MS培养基上,由茎尖与茎段可得到壮实的试管苗。由于该植物胚在第一年内成熟度甚低,因此用茎尖或茎段进行快繁殖远优于用胚来进行。从此项研究结果看,其繁殖率为2~n-3~n(n为∮月数)。     

海带褐藻糖胶的研究

本工作研究了我国人工养殖的海带叶片中褐藻糖的分布，及海带综合利用工业的废料碱凝沉物中褐藻糖胶的存在量和分离条件。海带叶片中的褐藻糖含量分布边缘比中部多，并从基部向尖部增加，即由0．3％增至1％以上。试验了用十六烷氯化吡啶法(CPC法)和乙醇沉淀法从碱凝沉物中分离褐藻糖胶的条件。两种方法的褐藻糖胶获得率分别为5．6％和4．4％(对干碱凝沉物)，其中的褐藻糖含量分别为24．7％和28．7％。碱凝沉物中的褐藻糖含量为1．4～3．5％。还研究了从褐藻糖胶以酸水解制取褐藻糖的诸条件，并分离出纸层析纯的褐藻糖结晶。     

包头南海湿地水体环境季节性变化与生态功能货币化评价

生态功能的定量化分析已日渐成为湿地生态系统服务价值研究的焦点之一。依据环境自我调节理论(Aaia假说)和应用市场价值法,对内蒙古包头南海湿地进行季节性水位和能见度测定,并对其生态系统服务功能进行货币化核算。结果表明:包头南海湿地核心区随着季节的变化,水位和能见度以及湿地生态功能发生着明显变化。该湿地每年固定CO2价值为133.12×104元;涵养水源价值为20889.54×104元;侵蚀控制价值为10420×104元;文化观光价值为3645×104元;珍稀鸟类价值160×104元,科学文化价值300×104元;遗产价值为5400×104元。非使用价值为6200×104元,备选、半备选价值为1840×104元。包头南海湿地生态系统每年提供于人类的服务价值为156446.06×104元。该研究结果可为干旱区其它湿地生态恢复与保育提供案例借鉴。     

Effects of dietary supplementation of nucleotides from late gestation to lactation on the performance and oxidative stress status of sows and their offspring

Increased metabolic burdens in breeding sows, which are induced by elevated systemic oxidative stress, could increase the need for nucleotides to repair lymphocyte DNA damage; however, de novo synthesis of nucleotides may be insufficient to cover this increased need. This study investigated the effects of dietary nucleotides on milk composition, oxidative stress status, and the reproductive and lactational performance of sows. Forty multiparous sows were assigned to 2 dietary treatments (Control group, and 1 g/kg Nucleotides group) based on a randomized complete block design using their BW at 85 d of gestation as a block. Sows from 2 groups were fed a restricted diet during gestation and ad libitum during lactation. The experiment lasted from 85 d of gestation to 21 d of lactation. The reproductive performance of sows and the growth performance of suckling piglets were measured. Oxidative stress parameters and milk components were also analysed. Data were analyzed using contrasts in the MIXED procedure of SAS. Sows in the Nucleotides group consumed more feed during the first week (P < 0.01) and from 1 to 21 d (P < 0.05) of lactation than those in Control group. Correspondingly, the litter weight gain of piglets showed a tendency to increase from cross-fostering to 9 d (P = 0.09) and from cross-fostering to 20 d (P = 0.10) in the Nucleotides group relative to the Control group. Additionally, the Nucleotides group was higher (P < 0.01) than the Control group in the concentrations of uridine 5''monophosphate, guanosine 5''monophosphate, inosine 5''monophosphate, adenosine 5''monophosphate and total nucleotides in milk. Furthermore, the Nucleotides group was higher (P < 0.01) than the Control group in the serum levels of total antioxidant capacity (P < 0.01) for sows at 109 d of gestation and glutathione peroxidase for weaning piglets, but lower at the levels of thiobarbituric acid-reactive substances (P < 0.05) in serum of weaning piglets. This study indicated that maternal dietary nucleotides could promote piglet growth, probably due to the higher lactational feed intake and higher concentration of nucleotides in the milk of sows, and lower oxidative stress for both sows and piglets.     

一体化微操作器误差分析与建模

为评价各种误差对微操作器精度的影响，以一体化超精密微操作器为研究对象，分析了加工误差、机构原理误差、测量误差、环境带来的误差以及驱动误差等造成微操作器精度降低的因素，建立了加工误差的偏微分方程解析模型，并用有限元仿真验证了加工误差模型的准确性。在详细分析误差源的基础上，提出了提高微操作器精度的措施。     

Building Enviornmental Monitoring System With COM

This article presents an implement of component using COM technology for collecting environmental monitoring data in environment monitoring system. The component makes the separation of data collection and data analysis available.Simultaneously by using the interface of connectable object in COM,itmakes the cooperation of the environment monitoring software with other parts of fault management software available,and also the seamless connection.It improves the system's performance by adding extensibility and potential cooperatibility.