Mapping of B-cell epitopes in the N-terminal repeated peptides of Anaplasma marginale major surface protein 1a and characterization of the humoral immune response of cattle immunized with recombinant and whole organism antigens

Major surface protein (MSP) 1a of the genus type species Anaplasma marginale (Rickettsiales: Anaplasmataceae) together with MSP1b forms the MSP1 complex. MSP1a has been shown to be involved in adhesion, infection and tick transmission of A. marginale, as well as to contribute to protective immunity in cattle. A differential antibody response to MSP1a and MSP1b was observed in cattle immunized with A. marginale derived from bovine erythrocytes (anti-MSP1a response) or cultured tick cells (anti-MSP1b response). In this study, we further characterized the MSP1a antibody response of cattle using several immunogens, including recombinant MSP1a (rMSP1a) protein, erythrocyte- or tick cell culture-derived A. marginale, or a combination of tick cell culture-derived A. marginale and rMSP1a. The MSP1a antibody response to all these immunogens was directed primarily against the N-terminal region of MSP1a that contains tandemly repeated peptides, whereas low antibody levels were detected against the C-terminal portion. Linear B-cell epitopes of MSP1a were mapped using synthetic peptides representing the entire sequence of the protein that were prepared by SPOT synthesis technology. Only two peptides in the N-terminal repeats were recognized by sera from immunized cattle. These peptides shared the sequence SSAGGQQQESS, which is likely to contain the linear B-cell epitope that was recognized by the pools of bovine sera. The average differential of antibody titers against MSP1a minus those against MSP1b correlated with lower percent reductions in PCV. A preferential antibody response to MSP1a was observed in cattle immunized with erythrocyte-derived, cell culture-derived plus rMSP1a or rMSP1a alone, and the percent reduction PCV was significantly lower in these cattle as compared with the other immunization groups. These results provide insight into the bovine antibody response against A. marginale and the role of MSP1a in protection of cattle against A. marginale infection.     

Discussion about Saving Energy in Refrigeratory

Food refrigeration is regarded as a high energy consuming trade. Under the long period system of state operated enterprise,there are many phenomenons of ignoring energy management and wasting energy. Energy consuming is not very clear for production.Consuming in our country is far more than the international standard and there is a distance between the middle_westland and the eastland. As a enterprise that faces the international market,it is important for it to strength the management so that the cost can be reduced. Considering those phenomenons of ignoring energy management and wasting energy in refrigeratory at present, some measures such as improved the unreasonable operation process, strengthening the energy management and automation to realize automatizing operation are improved to reduce the cost for refrigeratory trades.     

不同灌溉方式对棉田土壤物理性质的影响

以新疆生产建设兵团125团滴灌、沟灌、漫灌的棉田土壤为研究对象,分别测定不同灌溉方式棉田土壤的比重、容重、孔隙度以及团聚体结构和机械组成等物理性状.结果表明:棉田不同灌溉方式对其土壤各种物理性状产生了不同程度的影响.比重、容重表现为漫灌＞沟灌＞滴灌,而孔隙度则反之;土壤团聚体中粒径小于0.25 mm的微团聚体占了较大比重,良好结构团聚体的含量表现为滴灌＞沟灌＞漫灌,而微团聚体则相反;土壤机械组成中砂粒的含量占了较大比重,而砾石没有,砂粒、粉粒的含量均表现为漫灌＞沟灌＞滴灌,而粘粒则表现相反.     

Changes in organic carbon content and its physical and chemical distribution in paddy soils cultivated under different fertilisation practices

Purpose

Chemical protection facilitates soil organic carbon (SOC) sequestration and stabilisation due to a strong chemical binding with mineral surfaces and metal ions (e.g. iron [Fe], aluminium [Al] and calcium [Ca]). However, there is not much information regarding the role of chemical protection in SOC stabilisation in paddy soils, particularly in terms of the specific forms of organo-mineral complexes such as Fe-, Al- and Ca-bonded OC.

Materials and methods

We sampled paddy soils at the 0–20 cm soil layer from a long-term field experiment (initiated in 1981) conducted under humid subtropical conditions in China, which has five fertilisation treatments (i.e. control treatment without fertiliser [CK], chemical fertiliser only [CF], green manure [GM], Straw and Manure) with equivalent nutrient inputs (i.e. N, P₂O₅ and K₂O at the rates of 135–67.5–135 kg ha^?1, respectively, for both early and late rice) except CK. We determined the chemical binding forms of SOC and the associated soil properties in the particulate fraction (PF, >53 μm) and the mineral-associated fraction (MAF, <53 μm), which were obtained using a low-energy ultrasonic dispersion procedure, of a paddy soil in the long-term fertilisation experiment.

Results and discussion

Iron- and Al-bonded OC (Fe/Al-OC) was the dominant fraction and made up 55–70% of the total SOC in the paddy soil, while Ca-bonded OC (Ca-OC) was only a minor fraction (<4%). The Fe/Al-OC was mainly allocated in the MAF (52–67%), indicating that the chemical protection of SOC occurred mostly in the finer particle fractions. Long-term application of organic amendments increased the contents of bulk SOC by 27–34% (P < 0.05), of Fe/Al-OC by 9–16% and of Ca-OC by 35–83% (P < 0.05), whereas the sole application of chemical fertiliser had no significant effects on SOC contents of the paddy soil compared with the treatment without fertiliser inputs. Both amorphous Fe and Al extracted by ammonium oxalate (Fe_ox and Al_ox) showed significant correlations with Fe/Al-OC (r = 0.52 and 0.78, respectively), but Al_ox appeared to have a greater influence on C stabilisation in the paddy soil.

Conclusions

These results demonstrated that the dominant chemical binding forms of SOC in the paddy soils were Fe/Al-OC and amorphous Fe/Al oxyhydrates, especially amorphous Al, contributed mostly to the chemical stabilisation of SOC.

     

吡草醚在棉花及土壤中的残留分析方法研究

研究建立了吡草醚在棉花及土壤中的残留分析方法。棉叶和棉籽样品以乙腈提取,GCB/PSA固相萃取小柱净化,高效液相色谱测定。土壤样品以丙酮提取,C₁₈小柱净化。吡草醚在棉叶、棉籽和土壤中的最低检测浓度均为0.02 mg·kg^-1。吡草醚在棉叶、棉籽和土壤中的平均添加回收率（添加浓度为0.02~1 mg·kg^-1）分别为93.94%~101.65%、84.88%~98.62% 和85.49%~90.71%,变异系数分别为3.96%~8.06%、7.59%~10.37% 和5.59%~ 8.69%。方法的准确性、精确性和灵敏度均达到农药残留分析的要求。     

表皮生长因子调控猪肠上皮细胞中钠依赖Ⅱb型磷转运蛋白表达的细胞信号通路研究

本研究旨在探讨表皮生长因子(EGF)调控猪小肠上皮细胞IPEC-J2中钠依赖Ⅱb型磷转运蛋白(NaPi-Ⅱb)表达的分子机制。试验分别用EGF受体酪氨酸激酶抑制剂(tyrphostin AG1478)、蛋白激酶A(PKA)抑制剂(H89)、蛋白激酶C(PKC)抑制剂(k4393)、p38抑制剂(SB203580)、细胞外信号调节激酶(ERK)抑制剂(PD98059)、c-Jun氨基末端激酶(JNK)抑制剂(anisomycin)与EGF共同处理IPEC-J2细胞,利用Western blot检测相关通路蛋白及目的蛋白(NaPi-Ⅱb)的表达水平。结果显示:相较于对照组,EGF处理后NaPi-Ⅱb表达水平显著降低(P0.05);相较于无抑制剂组,EGF受体、PKA、PKC、丝裂原活化蛋白激酶(MAPK)/p38、MAPK/ERK1/2、MAPK/JNK的特异性抑制剂处理IPEC-J2后,NaPi-Ⅱb表达水平显著提高(P0.05),其中添加MAPK/ERK1/2特异性抑制剂显著降低了MAPK/ERK1/2在Tyr204位点的磷酸化水平(P0.05),添加MAPK/JNK的特异性抑制剂显著降低了MAPK/JNK1/2/3在Thr183和Tyr185位点的磷酸化水平(P0.05),说明该2组抑制剂对该通路的抑制作用是通过降低上述位点的磷酸化水平实现的。本研究结果表明EGF受体、PKA、PKC、p38、ERK和JNK均介导了EGF调控IPEC-J2细胞中NaPi-Ⅱb的表达。     

肉鸡血浆VLDL浓度的选择效应——对产蛋性能的影响

以零世代和一世代高、低脂系肉鸡为素材 ,个体记录高、低脂系母鸡产蛋性能 ,屠宰测定零世代 54周龄母鸡腹脂重 (率 ) ,探讨肥度性状与产蛋性能的关系 ,并研究零世代、一世代高、低脂系产蛋性能选择效应。结果表明 :在限饲条件下 ,腹脂重 (率 )与开产日龄、产蛋量表型相关很弱。腹脂重 (率 )与蛋重呈负表型相关趋势 ;零世代高、低脂系产蛋性能差异不显著。一世代低脂系比高脂系早开产 6.7d,低脂系 4 0周龄和 54周龄产蛋量显著高于高脂系 ,表明对血浆 VLDL浓度的选择使产蛋性能产生了有益的间接反应     

Effects of growth curve parameters on cow efficiency.

Weight-age data from 50 Retinta beef cows from 8 to 97 mo of age located in southwestern Spain were fitted to von Bertalanffy, Brody, and Richards functions to determine the relationship between growth curve parameters and cow efficiency. Only cows having at least 31 weights were included in the analysis. Von Bertalanffy, Brody, and Richards functions were fitted to weights of each cow. Relevant parameters of the three functions are A and K, associated with the asymptotic mature weight and rate of maturing, respectively. Criteria for comparisons among the three functions were computing difficulty, goodness of fit, and lack of bias of A. Productivity indicators were number of calves weaned during the first five calving seasons (NC), average birth weight (BWT), average weaning weight (WW), and average weaning weight per cow per year (WWY). The von Bertalanffy function was selected as the most appropriate. Least squares means for A and K were 650 +/- 8.17 kg and .038 +/- .001 mo-1, respectively. The values of NC, BWT, WW, and WWY were 4.0 +/- .11 calves, 38.2 +/- .4 kg, 218 +/- 5 kg, and 172 +/- 5 kg, respectively. Regression analysis for A indicated a decrease in NC when mature weight increased (P less than .05). There was a nonsignificant trend for heavier cows (higher A) to have calves with heavier BWT or WW. The value of WWY increased (P less than .05) with increased maturing rate (K) of cows. No significant associations were found between K and BWT or WW.(ABSTRACT TRUNCATED AT 250 WORDS)     

陕甘宁青蒙相邻干旱地区近530年旱涝灾害、突变分析及其趋势预测

本文以研究范围内有代表性的 1 3个气象台站自 1 470年至 2 0 0 0年旱涝等级资料为基础 ,采用平均旱涝等级值和旱涝灾害指数作为旱涝灾害的指标 ,较确切地反映出该研究范围内各年旱涝灾害轻重的程度 ;凭籍 L epage检验、功率谱等方法 ,对近 5 30年的不同时间尺度的阶段性、周期性和突变特点进行了分析 ;引进均生函数累加延拓的时序建模方案 ,对该区的旱涝灾害序列有很好的拟合和预测效果。