探究式教学改善生物化学教学效果的研究

针对生物化学课程理论性强、内容复杂抽象的特点,以塔里木大学动植物检疫专业学生为学习主体,将探究式教学引入教学过程,以学生为主体,通过课外学习,小组讨论和全班交流的形式培养学生的自学水平、提高学生的沟通交流、团队合作能力,结果表明该方法对学生的科学思维起到较好的促进作用.     

Wx^mp基因背景下可溶性淀粉合成酶基因SSⅡa和去分支酶基因PUL对水稻蒸煮食味品质的影响

【目的】分析在同一主效基因(Wx^mp)背景下可溶性淀粉合成酶基因SSⅡa和去分支酶基因PUL对稻米蒸煮食味品质的影响,以期为水稻品质遗传改良提供依据。【方法】选择在SSⅡa和PUL存在多态性而其他淀粉合成酶相关基因没有多态性的半糯品系宁0145和粳稻品种武运粳21进行杂交,获得F2群体与F3株系。利用分子标记,选择含有Wx^mp基因的F2单株与F3株系,将这些F2单株与F3株系分成SSⅡa^nPUL^n、SSⅡa^nPUL^w、SSⅡa^wPUL^n和SSⅡa^wPUL^w4种基因型(n和w分别表示该基因来源于宁0145和武运粳21),分析不同基因型蒸煮食味品质性状的差异,探讨同一Wxmp基因背景下不同SSⅡa和PUL等位基因对蒸煮食味品质性状的影响。【结果】不同基因型间蒸煮食味品质性状均存在显著差异,来源于武运粳21的SSⅡa^w基因和PUL^w基因分别使直链淀粉含量增加0.29%~1.00%和0.62%~1.18%,且PUL的效应大于SSⅡa,两者间存在互作效应。SSⅡa^w基因和PUL^w基因降低胶稠度和崩解值,提高了热浆黏度、冷胶黏度、消减值和回复值,对糊化温度、峰值黏度和峰值时间的作用较小。【结论】明确了Wx^mp背景下SSⅡa和PUL基因对稻米蒸煮食味品质的遗传效应,该研究结果为SSⅡa和PUL基因的分子标记辅助选择改良稻米品质提供了理论依据。     

河西荒漠灌区紫花苜蓿施肥效应及其基于数据包络分析法的经济效益研究

为科学准确地评判河西走廊苜蓿主产区紫花苜蓿饲草生产中施肥措施对其产品质量及生产收益的影响,本研究以“甘农3号”紫花苜蓿为材料,通过2016、2017年2年田间试验,以该区域紫花苜蓿饲草生产的平衡施肥推荐方案(N 103.5 kg·hm^-2、P₂O₅ 105 kg·hm^-2、K₂O 90 kg·hm^-2)为对照,探讨了不施肥及3种不完全施肥(缺氮偏施、缺磷偏施、缺钾偏施)处理下紫花苜蓿的生产性能,并采用数据包络分析法(DEA)对其经济效益进行分析。结果表明:与不施肥相比,施肥措施各处理均显著提高紫花苜蓿产量、蛋白总量,降低其酸性洗涤纤维和中性洗涤纤维,提高了相对饲用价值,从而改善了紫花苜蓿品质,并有效增加了经济效益;与氮、磷、钾平衡施肥相比,各偏肥处理的紫花苜蓿产量和品质均显著低于平衡施肥,尤以缺磷偏施的降幅最大,2016、2017年2年的产量和蛋白总量降幅分别达到25.9%、25.7%和33.4%、33.1%。因此,磷是河西荒漠灌区紫花苜蓿饲草生产的养分限制因子,氮、磷、钾对该地区紫花苜蓿生产性能影响顺序为:磷>氮>钾。运用数据包络分析法(DEA)分析出河西荒漠灌区紫花苜蓿的施肥效应为氮、磷、钾平衡施肥的经济效益最优,为DEA有效;不完全施肥的3个评价单元及不施肥评价单元为DEA无效,其中,不施肥经济效益最低,3个不完全施肥评价单元中的缺磷偏肥的紫花苜蓿经济效益比缺氮偏肥和缺钾偏肥更低;另外还以DEA模型推算出不同施肥措施下紫花苜蓿饲草生产经济效益改进的具体方案,其中,不施肥的紫花苜蓿饲草生产需调整的幅度最大,调整额度达10678.88 CNY·hm^-2,各施肥措施需调整的幅度排序为:不施肥>缺磷偏施>缺氮偏施>缺钾偏施。     

固态发酵醋糟饲料对育肥猪生长性能、养分表观消化率、血清指标及粪便中挥发性脂肪酸含量的影响

本试验旨在研究固态发酵醋糟饲料(SFVD)对育肥猪生长性能、养分表观消化率、血清指标及粪便中挥发性脂肪酸(VFA)含量的影响。选择体况相近[(59.04±0.33)kg]的健康“杜×长×大”三元杂交生长育肥猪60头,随机分为2个组,每组3个重复,每个重复10头猪。对照组饲喂基础饲粮+150 mg/kg土霉素钙,试验组饲喂基础饲粮+5%的SFVD。预试期6 d,正试期35 d。结果表明:与对照组相比,基础饲粮中添加5%的SFVD对育肥猪平均日采食量(ADFI)具有一定的促进趋势(P=0.056);显著降低了育肥猪饲粮中干物质(DM)、粗蛋白质(CP)、有机物(OM)和总能(GE)的表观消化率(P<0.05),对粗脂肪(EE)表观消化率有一定的促进趋势(P=0.052);显著提高了育肥猪血清谷草转氨酶(AST)和谷胱甘肽过氧化物酶(GSH-Px)活性(P<0.05),血清高密度脂蛋白(HDL)和免疫球蛋白A(IgA)含量也呈现出一定的升高趋势(P=0.055和P=0.077);显著提高了育肥猪粪便中丙酸含量(P<0.05),粪便中甲酸和总挥发性脂肪酸(TVFA)含量也呈现出一定的升高趋势(P=0.071和P=0.054)。由此可见,基础饲粮中添加5%的SFVD对育肥猪生长性能、肠道健康及免疫性能的提高具有潜在的促进作用。     

舒城县干汊河镇农村集体“三资”管理现状与建议

阐述了舒城县干汊河镇农村集体"三资"管理取得的成效,指出了管理过程中存在的问题,并提出了加强农村集体"三资"管理的建议。     

Typical hydrodynamic models for aquaculture nets: A comparative study under pure current conditions

The net is regarded as the most critical component in marine aquaculture facilities as it is the only barrier which protects the environment from fish escapes. Accurate predictions of the net cage deformation and drag force on the nets are needed, both for ensuring fish welfare and for dimensioning of the mooring system. Thus, an appropriate hydrodynamic model is essential. In practice, two types of hydrodynamic force models, i.e., the Morison type and the Screen type, are commonly used to calculate the hydrodynamic forces on nets. Application of the models depends on the underlying structural model and the availability of data. A systematic review of hydrodynamic models is therefore undertaken to compare the models and various parameterisations, in aid of model selection during the design. In this study, eleven commonly used hydrodynamic models, i.e., five Morison models and six Screen models, are reviewed comprehensively, and implemented into a general finite element (FE) solver for dynamic simulations. Sensitivity studies on different current velocities, inflow angles and solidities of the nets are carried out. Moreover, different wake effects are also considered in numerical simulations. The numerical results from different models are compared against existing experimental data under pure current conditions. Suggestions for selection of suitable hydrodynamic models are provided, based on the model comparison.     

不同处理对芹菜种子萌发过程中抗氧化系统及激素水平的影响

为研究芹菜种子的萌发机制,采用不同试剂组合（5 g/L NaOH+10% PEG、10% PEG+500 mg/L壳聚糖、5 g/L NaOH+500 mg/L壳聚糖）和不同温度(18、24、30℃)对芹菜种子进行处理,观察芹菜种子的萌发指标,并探究种子萌发过程中的抗氧化系统及内源激素水平的变化。结果表明,30℃对种子发芽率、发芽势及发芽指数提高具有促进作用,加快种子萌发进程。与蒸馏水对照组相比,试剂组合处理在18、24℃时种子发芽率、发芽势和发芽指数升高,促进种子萌发,18℃时5 g/L NaOH+500 mg/L壳聚糖处理下的发芽势最高,24℃时5 g/L NaOH+10% PEG处理下发芽势达到最大值;30℃时不同试剂组合处理间发芽率、发芽势和发芽指数无明显差异。18、30℃对种子具有一定程度的胁迫作用,种子SOD和CAT活性较24℃条件下有所增加;18℃时MDA含量和脯氨酸含量显著增加;5 g/L NaOH+10% PEG处理能显著降低MDA含量。萌发过程中,芹菜种子内部ABA含量下降,GA₃、ZA含量增加。试剂组合及适当高温有利于提高芹菜种子的发芽率、发芽势和发芽指数,促进种子萌发,提高种子萌发整齐度;芹菜种子萌发过程中抗氧化系统和激素水平会积极响应不同的处理条件。     

Effect of feeding different sources of selenium on growth performance and antioxidant status of broilers

ABSTRACT

1. This study was conducted to determine the effect of different sources of selenium (Se) on breast and liver tissue deposition, apparent metabolisable energy (AME), growth performance and antioxidant status of broilers, measured as Se content in liver and breast tissues and glutathione peroxidase (GSH-Px) in blood, when used in 0–35 d broiler chicken diets.

2. A total of 200 male Ross 308 broilers were used in the feeding trial, which comprised two dietary phases, a starter from 0 to 21 d and finisher from 21 to 35 d of age. Four treatments with 10 replications each were used. A control diet (C) was formulated that was sufficient in protein and energy (230 and 215 g/kg of crude protein and 12.67 and 13.11 MJ/kg of metabolisable energy, respectively), for both phases, but contained background Se only from the feed ingredients. Diet 2 (IS) was supplemented with 10.35 g/t inorganic, elemental source of Se. Diet 3 (SY) was supplemented with 136.36 g/t selenised yeast, an organic source derived from Saccharomyces cerevisiae. Diet 4 (SS) was supplemented with 0.666 g/t sodium selenite, an inorganic source.

3. Birds fed the SY diet consumed less and weighed less than those fed IS or C (P < 0.05; 0–35 d of age), but there was no difference compared to birds fed SS diets. There were no differences in FCR or dietary AME between broilers fed different Se sources. All diets containing supplementary Se increased concentrations in the liver and breast muscle, and for GSH-Px levels in blood compared to birds fed the C diet (P < 0.001). Birds fed SY diets had greater Se levels in liver and breast tissues compared to birds fed any of the other diets (P < 0.001).

4. Diets supplemented with Se had variable effects on broiler growth performances and antioxidant status. Feeding Se from a yeast source has higher transfer into breast tissues. Feeding different sources and levels of Se to birds in a more challenging situation to induce oxidative stress may bring more conclusive results.     

果蝇引诱物的引诱效果与杨梅甜度、反光率的关系

经室内筛选,得到一果蝇引诱物,并对其进行田间引诱效果试验。结果发现,在杨梅逐渐成熟至干枯过程中,杨梅甜度先增加后减少,反光率越来越低,果蝇引诱物的引诱效果则呈现先升高后降低再升高的趋势。     

口蹄疫疫苗对牛的应用效果调查

牛口蹄疫是传染性疾病,为研究青海省峰堆乡口蹄疫疫苗的免疫效果,于2018—2019年对该乡的7个村开展牛口蹄疫疫苗免疫效果调查,共调查牛634头,7个村总体的口蹄疫合格率为100.00%和97.56%,最低合格率为81.63%和88.63%。为更好地控制该类疾病发生流行,提升免疫效果,该文探讨口蹄疫疫苗免疫失败原因,并制定了相应的预防措施。