Seasonal Changes in Quality and Fatty Acid Composition of Black Mussel (Mytilus galloprovincialis)

The study was designed to assess the seasonal variations in the quality and lipid profile of mussel meat (Mytilus galloprovincialis) harvested along the Bulgarian coast of the Black Sea. The trial period lasted from June to October, and the sampling was carried out in the area of Varna Bay. Technological quality of the mussels was determined by measuring the water holding capacity (WHC) and cooking and roasting losses. Proximate composition, total aerobic plate count, and fatty acid analysis were carried out. Technological parameters and nutritional quality of the mussel meat were strongly affected by the season. During the summer, the mussels had higher mass, meat content, and meat yield (p < 0.001) compared to the early autumn, which corresponds to the lowest protein content during this season. Lipid profile showed seasonal variations in both individual and total fatty acid amounts (p < 0.001). Saturated fatty acids (SFA) had the highest content in summer, while monounsaturated fatty acids (MUFA) decreased gradually until the autumn. The content of polyunsaturated fatty acids (PUFA) reached its peak in October, contributing to the most favorable values of the nutritional indices of lipids in the early autumn.     

固态热带假丝酵母菌菌剂的发酵工艺研究

试验在单因素优化试验的基础上,采用正交试验进一步对热带假丝酵母菌固态发酵工艺进行研究,包括发酵时间、接种量、料水比、碳源、氮源、无机盐等因素,最终确定热带假丝酵母菌的固态发酵工艺。发酵条件:在自然pH值条件下,发酵温度30℃、发酵时间48 h、接种量11%、料水比1∶0.75。培养基成分:麸皮与甘油8.5∶1.5 (g/g)、尿素0.5%、磷酸二氢钾0。依照此工艺进行发酵,热带假丝酵母菌活菌数最高可达32.94×10⁸个/g。     

Aldh3a2a敲除对斑马鱼体色的影响

本研究探讨了Aldh3a2a在斑马鱼色素细胞发育中的意义及其对醛代谢和肝脏健康的影响。利用CRISPR/Cas9技术,我们成功敲除斑马鱼体内的aldh3a2a,导致黑色素细胞、黄色素细胞和虹彩细胞合成数量减少。转录组分析揭示了基因表达谱的变化,特别是与钾通道和类固醇生物合成途径相关的基因表达谱。我们的研究结果表明,aldh3a2a和aldh1a2之间存在调控关系,对视黄酸受体信号传导有影响。GO和KEGG富集分析强调了对色素细胞发育以外的细胞过程的更广泛影响。此外,aldh3a2a基因敲除会导致醛积累,导致肝脏异常,类似于Sj?gren-Larsson综合征,本研究揭示了aldh3a2a在斑马鱼中的多方面作用及其与人类遗传疾病的相关性。     

Influence of race and crossbreeding on casein micelles size

Casein (CN) micelles are colloidal aggregates of protein dispersed in milk, the importance of which in the dairy industry is related to functionality and yield in dairy products. The objective of this work was to investigate the correlation of milk CN micelles diameter from Holstein and Zebu crossbreds with milk composition (protein, fat, lactose, total and nonfat solids and milk urea nitrogen), somatic cell count (SCC), age, lactation stage and production. Average casein micelles diameters of milk samples obtained from 200 cows were measured using photon correlation spectroscopy and multiple regression analysis was used to find relationship between variables. CN micelle diameter, SCC and nonfat solids were different between animals with different Holstein crossbreed ratios, which suggests influence of genetic factors, mammary gland health and milk composition. Overall, results indicate the potential use of CN micelle diameter as a tool to select animals to produce milk more suitable to cheese production.     

Pyrantel resistance in two herds of donkey in the UK

Resistance to currently available anthelmintics is a serious phenomenon which is prevalent globally. Cyathostomins are one of the major parasites, and are of primary concern in donkeys. There have been reports of emerging resistance to pyrantel, but the status of pyrantel resistance in donkey populations in the UK is largely unknown. This report investigates pyrantel resistance in two geographically isolated donkey herds in the South West of England. The first herd had suspected pyrantel resistance, with already established resistance to other anthelmintics. In the second herd the efficacy of pyrantel was not suspected at the time the study took place. Faecal Egg Count Reduction Test (FECRT) was carried out, revealing large scale resistance. Eighty one percent of the first herd and 73% of the second herd had a FEC of less than 95% after treatment, and anthelmintic resistance was confirmed using the World Association for the Advancement of Veterinary Parasitology guidelines. These findings indicate that anthelmintic resistance to pyrantel exists in both tested donkey populations and illustrate the continuing development of resistance through different classes of chemotherapeutics.     

A computer vision system for oocyte counting using images captured by smartphone

This work proposes a computer vision procedure for counting Twospot astyanax (Astyanax bimaculatus) oocytes in Petri dishes using images captured by smartphone. First, the proposed procedure uses simple linear iterative clustering (SLIC) to divide the images into groups of pixels (superpixels). Then, based on their color and space characteristics, the images are classified into light background, dark background, dirt, or oocyte by a machine learning algorithm. Five different types of machine learning algorithms were tested: support vector machines (SVM), decision trees using the algorithm J48 and random forest, k-nearest neighbors (k-NN), and Naive Bayes. To train the algorithms, 8.578 superpixels were classified by an expert into oocyte (n = 354), dirtiness (n = 651), dark background (n = 3.622), and light background (n = 3.951). Of the five learning algorithms, SVM obtained the best result with 97% correct oocyte recognition. Given the wide availability of smartphones, we therefore conclude that the presented procedure can be a valuable tool in future experiments and studies on fertilization and hatching success in Twospot astyanax.     

应用发酵牛粪垫料提高奶牛生产性能的研究

[目的]评估发酵牛粪对奶牛的安全性,并检验其在生产中的应用效果.[方法]比较发酵前后牛粪水分的变化,检测其细菌种类和数量,评价发酵牛粪的安全性.[结果]发酵牛粪没有能诱使奶牛发病的致病菌.临床应用时,试验组牛舍NH3含量稍高于对照组;试验组乳房炎和肢蹄病的发病率均低于对照组.2组隐性乳房炎增幅近似;试验组牛体清洁度评分优于对照组;试验组躺卧率高于对照组;发酵牛粪对奶牛的奶产量基本没有影响.[结论]发酵牛粪作为牛床垫料是可行且安全的.     

变质鸡蛋中蜡样芽孢杆菌的分离与鉴定

从山东地区保存超过14 d大范围出现变质鸡蛋中分离到一株细菌,经过培养特性、生理生化鉴定和16S rDNA鉴定,鉴定为蜡样芽孢杆菌(Bacillus cereus).分别将变质鸡蛋、煮熟的变质蛋、健康鸡蛋进行厌氧培养和细菌计数,发现健康鸡蛋和煮熟的变质蛋无蜡样芽孢杆菌,而变质鸡蛋中的细菌数量达到1.3×108CFU/g.本试验表明,蛋黄中过量的蜡样芽孢杆菌可能与鸡蛋变质有关,应注意过量添加蜡样芽孢杆菌可能影响蛋品的保鲜和食用安全性.     

数字图像处理技术在棒材计数中的应用

利用数码相机获取棒材端面的图像，通过对图像格式转化、灰度化处理得到灰度图像，再进行平滑处理抑制噪声、锐化处理突出目标、选择合适的闻值转换为二值图像，然后进行形态学腐蚀操作去掉棒材之间的粘连，最终得到分割效果较好的图像，为后续棒材的计数奠定了基础。