水稻胚乳双向电泳技术体系的优化分析

为比较同一杂交组合不同直链淀粉含量后代在灌浆期胚乳内蛋白表达差异,文章建立了一套适合灌浆期水稻胚乳蛋白的双向电泳技术,探讨了胚乳蛋白的提取、等电聚焦上样量的选择、胶条转移等双向电泳的一些关键技术。结果表明,一次溶解蛋白样品,TCA-丙酮法优于酚法蛋白提取,300μg上样量为最适上样量,能得到清晰、分离效果好、蛋白点数较多的图像。     

动物对应激反应的调节机理综述

应激往往是由多种因素造成的非特异性反应,对动物的健康和生产产生负面影响,它会使动物免疫力下降,增加动物患病的几率.对于猪群来说,饲养场地变换、运输、密度过大、温度过高或过低、疫苗注射、疾病等都可以造成应激.应激反应是动物机体对这些紧张性事件的适应性反应,主要是机体的神经、内分泌等系统对内外环境刺激的系统性反馈,以此来使...     

露地菊‘纽9717’的茎叶离体快繁体系

以露地菊‘纽9717’(Chrysanthemum×grandiflora ‘niu9717’)无菌苗为试验材料, 进行茎段(含腋芽)离体快繁体系和离体叶片不定芽再生体系的研究。结果表明, 最佳茎段增殖培养基为MS+6-BA 0.3 g·L-1+KT 0.5 g·L-1+NAA 0.5 g·L-1, 平均增殖系数为3.2;最佳叶片离体再生培养基为MS+6-BA 2.0 g·L-1+NAA 0.5 g·L-1, 6-BA与NAA组合更有利于愈伤组织分化, 愈伤组织诱导率为100%, 愈伤组织分化率为92.3%, 繁殖系数为8.9, 其中分裂素KT及TDZ不利于愈伤组织诱导及不定芽分化, 生长素2, 4-D能有效诱导愈伤组织, 但抑制不定芽分化;最佳生根培养基为1/2MS+IBA 0.05 g·L-1, 生根率达100%, 平均生根数为12.08, 平均根长1.5 cm, 移栽成活率为100%, 高浓度生长素能诱导根形成但抑制根的伸长。     

北票市畜牧技术推广体系改革与建设项目实施效果及建议

深化基层畜牧技术推广体系改革与建设,旨在提升基层畜牧技术推广体系公共服务能力。北票市畜牧技术推广站通过一系列措施,建立健全新型基层畜牧技术推广服务体系。基层畜牧技术推广体系改革与建设推进了体制机制创新,完善了工作机制,夯实了人才基础,提高了服务效能。通过两年的实践证明,基层畜牧技术推广体系改革与建设项目实施,有效解决了畜牧技术推广服务体系“最后一公里”问题。     

Plasma renin activity and plasma concentrations of aldosterone, cortisol, adrenocorticotropic hormone, and alpha-melanocyte-stimulating hormone in healthy cats

A pathogenetic role of the renin-angiotensin-aldosterone system has been implicated in cats in both systemic arterial hypertension and hypokalemic myopathy. Yet, measurement of plasma aldosterone concentrations (PACs) and plasma renin activity (PRA) has not unequivocally pointed to hyperaldosteronism as a cause of these conditions. To obtain appropriate reference ranges, this study included a large number (130) of healthy house cats of different breeds without a history of recent illness and plasma concentrations of urea and creatinine below the upper limit of the respective reference ranges. In addition, the pituitary-adrenocortical axis was studied by measuring plasma concentrations of adrenocorticotropic hormone (ACTH), alpha-melanocyte-stimulating hormone (alpha-MSH), and cortisol. Reference ranges for PACs (110-540 pmol/L; 40-195 pg/mL), PRA (60-630 fmol/L/s; 0.3-3 ng/mL/h), and the aldosterone to renin ratio (ARR) (0.3-3.8) were very similar to those established in the same laboratory for humans in a supine position. No breed differences were found. The ARRs in neutered cats were significantly higher than in intact cats, primarily because of low PRA in neutered cats. The ARRs of cats > or = 5 years of age were significantly higher than those of cats < 5 years of age. The plasma concentrations of ACTH, alpha-MSH, and cortisol did not correlate significantly with PAC. Thus, although blood sampling was performed in cats in nonstandardized positions and was associated with a wide variation of stress responses, the references ranges of PAC, PRA, and ARR were similar to the relatively narrow limits established for humans under standardized conditions. The effects of neutering and aging on PRA and ARR warrant further investigation.     

Productivity of different cow genetic groups in dual-purpose cattle production systems in south-eastern Mexico

The objective was to evaluate the effect of cow genetic group, nutritional level and their interaction on some economically important traits of dual-purpose herds managed under field conditions. Nine herds were monitored during a production cycle in Yucatan, Mexico. Herds were grouped into four nutritional levels (NL) based on the metabolizable energy (ME) apparently available on pasture, nutritional management, and milk production. Cows were classified into three genetic groups (GG): low (≤25%), middle (25–75%) and high (≥75%) graded for Bos taurus inheritance. Total milk sold (TMS), days in milk (DIM), TMS adjusted to DIM within each NL (TMSA), body condition score (BCS) at calving, changes of BCS during lactation (CBCS), calf weaning weight (WW), age at weaning (AW), kg of calf weaned per cow (KWC) and calf mortality were studied. The statistical model included the fixed effects of NL, GG, month of calving (MC), parity number (PN) and BCS at calving and GG × NL interaction. The effects of NL, GG, MC, PN and GG × NL were significant (p < 0.05) for TMS, KWC. As expected, TMS increased with NL from 562.4 ± 106 kg for NL1 to 2366.3 ± 100.1 kg for NL4. KWC was greatest for NL2 (138.6 kg) followed by NL1 (135 kg); the lowest KWC corresponded to NL4 (96.0 kg) (p < 0.05). TMS values for the middle (1727 ± 94.7 kg) and the high graded GG (1603.5 ± 83.5 kg) were twice those for the low graded GG cows (828.5 ± 95 kg) (p < 0.05). KWC was also higher for the middle graded group (152.8 kg) than for the low or (104 kg) or the high graded GG (118 kg) (p < 0.05). With better nutrition cows of all GG improved their milk performance but not the calf traits. CBCS was negative for all GG. The highest BCS lost was for cows in NL1 and NL2 and for cows in the high graded GG (p < 0.05).     

Magnetic resonance imaging appearance of the brain and cervical spinal cord in an edema disease affected pig

A 7‐week‐old male pig was presented with signs of a central nervous system disorder. An MRI of the head and cervical spine was performed immediately after euthanasia. The MRI revealed multifocal bilaterally symmetric T2‐weighted hyperintense lesions in the brain and spinal cord, likely due to a toxic metabolic process. Histopathological examination supported the MRI findings and confirmed the diagnosis of edema disease due to Shiga‐like toxin produced by Escherichia coli. This is the first case published of the MRI findings in an edema disease affected pig.     

重庆上市公司互保圈现象的会计思考

在市场经济环境下，贷款担保作为上市公司融通资金的一种方式，是企业的一种正常的经营行为。它可以减少交易风险、促进资本市场发展。然而，目前由于种种原因，上市公司互保不仅没有起到化解市场风险的作用，反而加大了证券市场和金融市场的风险，严重扰乱了资本市场的正常运行。因此，本文拟通过思考重庆“互保圈”现象，分析“互保圈”形成的原因及危害，并由此提出相应的对策与建议。     

九龙牦牛体型线性性状研究

对24头九龙牦公牛和252头牦母牛的9个体型线性性状进行主成份和因子分析，牦公牛被提取3个因子，累积方差贡献率达86.407％，分别是：体型综合信息因子、胸宽因子和十字部高－－腰角宽因子；牦母牛被提取5个因子，累积方差贡献率达81.93%，分别是：高度因子、后躯－－长度因子、胸部特征因子、管围因子和胸宽－－尻斜长因子。牦公牛3个因子表达式分值、牦母牛5个因子表达式分值，用于牦牛体型评估，具有较高的选育和经济价值。     

草地对全球气候变化的响应及其碳汇潜势研究

 本研究用综合顺序分类法（ＣＳＣＳ）分析了１９５０－２０００年和２００１－２０５０年期间的草原类型演替及碳汇动态。证明中国草地的碳汇主体依次是冻原和高山草地、温带湿润草地、斯泰普草地和半荒漠草地大类,占中国潜在草地总面积的８５．５２％,年碳汇潜力占中国潜在草地年碳汇潜力的９３．２９％。全球草地的碳汇主体是萨王纳、冻原和高山草地大类,两者的面积和占全球潜在草地总面积的４８．５０％,年碳汇潜力占全球潜在草地年碳汇潜力的７２．２２％。在全球气候暖干化的强（Ａ２ａ）、弱（Ｂ２ａ）情景下,与当前（１９５０－２０００年）情景相比,中国将呈现草地面积减少,林地面积增加的态势;与中国的趋势相反,全球将呈现草地面积增加,林地面积减少的态势。在全球暖干化的Ａ２ａ和Ｂ２ａ模式下,草地年碳汇潜力,中国将分别提升１４．６％和１８．５％,全球将分别提升１７．３％ 和１６．８％。但两者的增长方式不同,全球是以温带湿润草地大类年碳汇潜力大幅增加为特征,而中国是以负增长为特征。我国的暖干化趋势在草地年碳汇潜力上的反映较之全球更强烈。尽管造成全球气候暖干化的自然因素远非人力所能控制,但系统问题只能靠系统综合的办法治理。这是草地工作者当前的使命。