Analysis of Inter-Individual Bacterial Variation in Gut of Cicada Meimuna mongolica (Hemiptera: Cicadidae)

Intestinal bacterial community plays a crucial role in the nutrition, development, survival, and reproduction of insects. When compared with other insects with piercing-sucking mouthparts, the habitats of cicada nymphs and adults are totally different. However, little is known about the differences in the gut bacterial communities in the nymphs and adults within any cicada species. The diversity of bacteria in the gut of nymphs and adults of both genders of Meimuna mongolica (Distant) was studied using the denaturing gradient gel electrophoresis (DGGE) method. Few inter-individual variations among gut microbiota were observed, suggesting that M. mongolica typically harbors a limited and consistent suite of bacterial species. Bacteria in the genera Pseudomonas and Enterobacter were the predominant components of the gut microflora of M. mongolica at all life stages. Bacteria of Pantoea, Streptococcus, and Uruburuella were also widespread in the cicada samples but at relatively lower concentrations. The relative stability and similarity of the PCR-DGGE patterns indicate that all individuals of this cicada species harbor a characteristic bacterial community which is independent from developmental stages and genders. Related endosymbionts that could be harbored in bacteromes of cicadas were not detected in any gut samples, which could be related to the cicada species and the distribution of these endosymbionts in the cicada cavity, or due to some of the possible limitations of PCR-DGGE community profiling. It is worthwhile to further address if related cicada endosymbiont clades distribute in the alimentary canals and other internal organs through diagnostic PCR using group-specific primer sets.     

椰壳纤维分离机的设计

针对传统化学及人工分离椰壳纤维生产效率低、污染严重、纤维损伤率高、劳动强度大等弊端,设计出了自动化程度较高的椰壳纤维分离机械。该机械具有生产效率高、结构简单、实用性强等特点。椰壳纤维分离机械的研究不仅填补了我国机械分离椰壳的空白,同时也对椰子产业规模化起到了极大的推动作用。     

经络穴位给药系统在兽医临床上的应用

经络穴位给药系统以中医经络理论为基础,具有经穴效应和药物效应的双重治疗特性,已广泛应用于兽医临床.目前,兽医临床上常用穴位给药方式是穴位埋植和穴位注射,而常用穴位主要是后海穴、百会穴、肺龠穴.随着经络穴位给药系统的广泛应用,新型经络穴位给药制剂和经络穴位给药作用机理已成为经络穴位给药系统研究的重点.     

基于介观量子理论的最佳PCR引物浓度计算

对PCR反应体系而言,引物浓度过高或过低对反应体系都存在严重的影响,只有合理的浓度区间才能对整个反应高效有序地进行发挥重要的作用.降低PCR引物间的量子效应有利于提高引物间PCR反应的独立性和确定性,故粒子自由程至少是相位关联长度的10倍,并由此可以得到引物反应浓度的上限;粒子非弹性散射的最大自由程是粒子运动的极限自由程,依此可以得到引物反应浓度的下限,从而确定了引物的有效浓度区间;引物浓度-扩增效率曲线一般呈单峰分布,利用黄金分割法可以精准、迅速地确定引物最佳浓度。基于上述计算方法,长20、25、30 nt的引物有效浓度区间分别为0.027~5.280、0.019~7.310、0.015~9.461 umol·L-1。引物有效浓度区间及最佳浓度对PCR反应体系的反应效率与速率、PCR产物质量等具有决定性的作用,而应用理论方法确定它们将对理论指导实验具有重要的意义。     

基于超平面构建的高光谱异常目标检测方法

高光谱遥感影像具有光谱分辨率高、图谱合一的特点,影像中的地物组成也多种多样,针对图像数据中目标出现概率较小、检测概率较低等问题,本文提出了基于超平面构建的高光谱数据目标异常检测方法。它通过对高光谱数据的结构分析,构建出高维空间中的背景超平面算子,以待测像元在其正交子空间的投影值来表征异常程度的大小。通过OMIS和AVIRIS实测数据验证,并与RX算法相比较,基于超平面构建的高光谱异常检测算法能够在多种背景环境下检测出纯度高、光谱差异大的异常像元,并具有较高的检测率和较低的虚警率,因此具备了有效性和较好的实用性。     

Variation of Color and Ray Pattern in Juvenile Shells in Hatchery‐produced Freshwater Triangle Pearl Mussels,Hyriopsis cumingii,in China

The variation and inheritance of juvenile shell color and pigmentation pattern in the freshwater mussel, Hyriopsis cumingii, were reported in 1‐yr‐old progeny of eight families. There were three distinctive phenotypes of shell color and pigmentation patterns observed, including a greenish‐brown shell with radial rays, yellowish‐brown shell with radial rays, and yellowish‐brown shell without radial rays. There were no greenish‐brown individuals without radial rays. The shell color phenotypes showed variation with the growth in juvenile Stage I (1–3 cm in shell length), and the percentage of individuals with radial rays increased once they reached a shell length of 11 mm and then stabilized after reaching 20 mm in shell length. Shell color differentiation became more apparent at a shell length of 26 mm. Results of chi‐square tests of the segregation ratio of shell color or ray phenotypes obtained from eight families at juvenile Stage II (6–9 cm in shell length) suggested that greenish‐brown is controlled by a dominant allele (G) and yellowish‐brown‐shell phenotype is by a recessive allele (y); the ray pattern phenotype is controlled by a recessive (r) and a dominant allele (R) at a single locus. Shell color phenotypes may be a useful genetic marker for future selective breeding of triangle pearl mussels.     

Sulfadiazine pharmacokinetics in grass carp (Ctenopharyngodon idellus) receiving oral and intravenous administrations

This study aimed to examine the bioavailability (BA) and pharmacokinetic (PK) characteristics of sulfadiazine (SDZ) in grass carp (Ctenopharyngodon idellus) after oral and intravenous administrations. Blood samples were collected at predetermined time points of 0.083, 0.17, 0.5, 1, 2, 4, 8, 16, 24, 48, 72, and 96 hr (n = 6). The samples were extracted and purified by organic reagents and determined by the ultra‐performance liquid chromatography. The software named 3P97 was used to calculate relevant PK parameters. The results demonstrated that the concentration–time profile of SDZ was best described by a one‐compartmental open model with first‐order absorption after a single oral dose. The main PK parameters of the absorption rate constant (K_α), the absorption half‐life (t_{1/2 Kα}), the elimination rate constant (K_e), the elimination half‐life (t_1/2Ke), and the area under concentration–time profile (AUC_0‐∞) were 0.3 1/h, 2.29 hr, 0.039 1/h, 17.64 hr, and 855.78 mg.h/L, respectively. Following intravenous administration, the concentration–time curve fitted to a two‐compartmental open model without absorption. The primary PK parameters of the distribution rate constant (α), the elimination rate constant (β), the distribution half‐life (t_1/2α), the elimination half‐life (t_1/2β), the apparent distribution volume (V_SS), the total clearance (CL), and AUC_0‐∞ were 9.62 1/hr, 0.039 1/hr, 0.072 hr, 17.71 hr, 0.33 L/kg, 0.013 L h^?1 kg^?1, and 386.23 mg.h/L, respectively. Finally, the BA was calculated to be 22.16%. Overall, this study will provide some fundamental information on PK properties in the development of a new formulation SDZ in the future and is partially beneficial for the appropriate usage of SDZ in aquaculture.     

计算机视觉技术在智慧羊场中的研究进展

智慧羊场具有科学化、标准化管理的优点,是羊场转型发展的趋势。计算机视觉技术是人工智能的核心,可以实现非接触性、自动化、实时监测羊的个体信息。本文总结并分析了计算机视觉在羊场的个体识别方法、行为识别方法、体尺与体重估测、疾病监测的研究现状,并指出计算机视觉在智慧羊场的进一步发展趋势。 [关键词] 计算机视觉|智慧羊场|个体识别|行为识别|体尺与体重估测|疾病监测     

2018—2020年湖南省宁乡市牛羊布鲁氏菌病血清学监测

为掌握宁乡市牛羊布鲁氏菌病防控净化效果,2018—2020年在全市开展了牛羊布鲁氏菌病监测工作。共检测1 932个牛羊养殖场户,采集牛羊血清样本32 356份,应用虎红平板凝集试验(RBPT)进行初筛,竞争酶联免疫吸附试验(c ELISA)进行复核。结果显示:2018—2020年共检出阳性场户10个(羊场户9个、牛场户1个),平均场户阳性率为0.52%;检出阳性样品82份,平均个体阳性率为0.25%。2018年场户阳性率为1.57%,个体阳性率为0.33%,2019年场户阳性率为0.15%,个体阳性率为0.06%;2020年场户阳性率为0.24%,个体阳性率为0.41%。2018年检出阳性乡镇5个,2019年1个,2020年2个。结果表明,宁乡市布鲁氏菌病流行得到有效控制,流行范围大幅缩小,但传播风险依然存在,还需继续加大监测和防控力度,加快推进布鲁氏菌病净化。本研究为宁乡市布鲁氏菌病防控提供了数据支撑。     

Betaine Alleviates Heat Stress-Induced Hepatic and Mitochondrial Oxidative Damage in Broilers

The aim of this study was to evaluate the effects of dietary betaine (BET) on growth performance, redox state, and related gene expression in broilers under heat stress (HS). A total of 144 21-day-old male broiler chickens with similar body weights were assigned randomly to three treatments with six replicates (eight chickens per replicate cage). Broilers in the control (CON) group were kept at thermoneutral (TN, 22±1°C) conditions and fed a basal diet until they were 42 days of age. Broilers in the other two groups (defined as HS and HS + BET) were exposed to HS (34±1°C, 8 h/day) and fed the basal diet without or with 1000 mg/kg BET, respectively. Rectal and cockscomb temperature of broilers was increased (P<0.05) in HS and HS + BET groups compared with the CON group, whereas there was no difference between HS and HS + BET groups. Dietary BET supplementation restored (P<0.05) average daily gain (ADG) and average daily feed intake (ADFI) of broilers and reversed (P<0.05) the increase in serum alanine transaminase (ALT) activity and malondialdehyde (MDA) content in the liver tissue of broilers under HS. The HS + BET group had higher (P<0.05) activities of superoxide dismutase (SOD) and glutathione peroxidase (GPX) in the liver tissue and mitochondria than the HS group, and the same pattern was observed for glutathione (GSH) and GSH/glutathione disulphide (GSSG) in the liver tissue. The decreased mRNA levels of GPX1 and uncoupling protein (UCP) in the liver induced by HS were restored by BET supplementation. In conclusion, dietary BET supplementation can alleviate HS-induced hepatic and mitochondrial oxidative damage of broilers by regulating mRNA expressions of GPX1 and UCP.