对控制工程基础课程教学的思考

针对控制工程基础课程目前存在的主要问题，探讨相应的解决方案，通过讲好绪论提高学生的学习积极性，通过灵活的教学方式提高教学效果，通过增加考核方式使学生的的创新能力和动手能力得到发展。     

Pathological analysis of batch safety testing of veterinary vaccines using small laboratory animals

Batch safety tests (BSTs) of veterinary vaccines are conducted using small laboratory animals to assure the safety of vaccines according to several criteria, including clinical signs and change in body weight. Although the latter is used as an evaluation index in BSTs, there have been no reports on the internal changes that affect body weight during the test period. Therefore, we analyzed BST via pathological examination of the tested animals. Here, BSTs were performed for 176 batches using mice and 126 batches using of guinea pigs. Most of the gross findings could be classified into four lesion types (nodules, adhesions, ascites, no apparent signs), with only one vaccine inducing lesions that could not be classified into any of these four types. Histopathological examination revealed that the reactions caused by BST were pyogenic and/or granulomatous inflammation. Nodular or adhesive lesions comprised more severe pyogenic granulomatous inflammation than ascites or cases with no apparent gross lesions. These nodular or adhesive lesions were more frequently induced by vaccines that contained an adjuvant than by vaccines that did not contain an adjuvant. The cases with “exceptional” gross findings histologically presented severe necrosis of the hematopoietic system. Additional testing showed that these “exceptional” lesions were induced when a specific type of light liquid paraffin was injected along with other vaccine additives. Our results show that body weight loss and/or lesions during BST were induced by proinflammatory properties of the tested vaccines and that BST is a sensitive method for detecting unexpected effects of vaccine components.     

Loser cows in Danish dairy herds: definition, prevalence and consequences

During the last few years, many Danish dairy farmers have expressed increasing concerns regarding a group of cows, which we have chosen to term ‘loser cows’. Until now, a loser cow has not been described scientifically. We defined a loser cow on the basis of a clinical examination of the cow. A total of 15,151 clinical examinations were made on 6,451 individual cows from 39 randomly selected, large Danish dairy herds with loose-housing systems using a clinical protocol. Scores for the clinical signs lameness, body condition, hock lesions, other cutaneous lesions, vaginal discharge, condition of hair coat and general condition were converted into a loser cow score. Cows with a loser cow score of 8 or more were classified as loser cows. The overall prevalence of loser cows was 2.15%, 4.50% and 2.98% during the first, second and third round of herd visits, respectively.

The associations between the loser cow state and milk production, mortality, morbidity, culling and workload for the farmer were evaluated using data from herd visits and from the Danish Cattle Database and a number of different statistical techniques. It was concluded that the loser cow state has significant negative consequences for both the farmer and the cow. On average, loser cows yielded 0.61 to 2.24 kg energy corrected milk less per day than non-loser cows depending on parity. Hazard ratio for death or euthanasia was 5.69 for loser cows compared to non-loser cows. Incidence rate ratio for disease treatments was 0.69 for non-loser cows compared to loser cows. Loser cows were often culled in an ‘unfavourable’ way and generally caused extra workload for the farmer.

A simplified version of the loser cow score was evaluated and is recommended for future research and use in practice.     

生态核不育大麦花粉的扫描电镜观察

对生态核不育大麦不育株和可育株的成熟花粉以及对照品种８９０９和鄂啤２号的成熟花粉进行了扫描电镜观察，发现生态核不育大麦不育株和可育株均含有空秕状和圆形、饱满两类花粉；两对照品种的花粉为圆形、饱满类型。生态核不育大麦可育株的圆形花粉与对照品种花粉一样，其萌发孔有明显突出的孔盖；而生态核不育大麦不育株的圆形花粉则无孔盖。因此，可认为萌发孔孔盖的有无是生态核不育大麦可育与不育花粉的典型鉴别特征。     

琯溪蜜柚砂囊粒化的无损检测

摘 要：柑橘砂囊粒化是柑果成熟期与采后贮藏期的常见生理性病害,严重影响果实品质。本文采用1.5 T 高场磁共振成像仪对采后贮藏30 d的琯溪蜜柚[Citrus grandis (L.) Osbeck]果实进行磁共振扫描检查,并以同层断面解剖图为对照,评估磁共振成像（MRI）应用于柑橘砂囊粒化症无损检测的有效性。结果表明, MRI检测中,T2WI能够显著区分果肉组织与海绵层组织的信号差异,其信号强度可代表果实组织相对含水量;T2WI信号在砂囊粒化部位强度显著降低,病变组织的失水特征清晰,与解剖结果一致。T2WI对砂囊粒化的确诊率100%,显著优于T1WI成像的识别率41.7%（χ2 = 5.76,P = 0.016）;T2WI和T1WI均能显示种籽照影,但T2WI对果肉组织影像的分辨率优于T1WI,因此MRI的T2WI分析可作为一种无损检测方法,对柚商品果实上市前砂囊粒化症发生程度以及种籽有无进行评估。     

“食品添加剂”课程教学模式改革研究

在当今“慕课”和“金课”日益盛行的教学模式下,针对“食品添加剂”课程传统教学“以教师讲授为主”、教学模式陈旧、学生被动接受知识、课程考核方式单一、学习成效不显著等缺点,从教学方式、考核方式进行初步改革探讨,使课前预习和课堂听课有机融合,推进翻转课堂,逐步向“金课”建设过渡,提升学生自主学习能力,促进教学质量提高。     

基于声振信号对称极坐标图像的苹果霉心病早期检测

为实现苹果早期霉心病较高精度的检测,该研究采用对称极坐标法（Symmetrized Dot Pattern,SDP）将苹果声振信号变换为雪花图,然后采用AlexNet、VGG16和ResNet50卷积神经网络以迁移学习方式深度挖掘SDP雪花图像的特征信息,将其输入到支持向量机（Support Vector Machine,SVM）分类器,对霉心程度≤7%的苹果进行检测。研究结果表明,当时间间隔系数为25和角度放大因子为50°时,健康果与早期霉心果声振信号的SDP图形状特征差异最大,在此条件下获取的SDP图经卷积神经网络AlexNet、VGG16和ResNet50提取特征并构建了不同核函数的SVM霉心果检测模型,在各类SVM模型中,ResNet50-SVM-gaus（高斯基）模型用相对较少的训练时间和参数量可取得训练集霉心果较高分类准确率,经超参数优化训练该模型对健康果和早期霉心果测试集不平衡样本（10∶1）的总体分类准确率达到96.97%,平均查准率、平均查全率、平均加权调和均值、Kappa系数和马修斯相关系数值分别为80.19%、90.36%、86.21%,82.54%和82.68%,该模型不仅对多数类的健康果保持较高分类准确率,而且对少数类的早期霉心果也具有较高判别能力。这些研究结果为声振法应用于果蔬内部病害的早期在线检测系统研发提供了技术支撑。     

16S rRNA在海洋微生物系统分子分类鉴定及分子检测中的应用

16SrRNA序列分析作为微生物系统分类的主要依据已得到了广泛认同，随着微生物核糖体RNA数据库的日臻完善，该技术成为细菌分类和鉴定的一个有力工具。本文总结了16SrRNA作为海洋微生物系统分子分类鉴定的理论基础和具体方法，分析了用16SrRNA研究海洋微生物的进化关系，并且对16SrRNA在海洋微生物分子检测中的应用作一评述。     

不同产地烤烟烟气有害成分的检测与分析

对河南不同产地,云南红河和津巴布韦国的烤烟单料烟中的焦油,烟气烟碱,ＣＯ等有害成分的播放量进行了检测和分析比较,并对烟叶化学成分中的还原糖,烟碱,Ｋ２Ｏ,Ｃｌ＾－,ＳＯ＾２－４及有效钾进行分析。     

加强审稿环节提高热区农业科技期刊质量

根据我国热区农业科技期刊发展面临的问题,探讨从审稿环节入手提高热区农业科技期刊学术影响力及期刊质量的途径。