Exploring the microbial composition of Holstein Friesian and Belgian Blue colostrum in relation to the transfer of passive immunity

For centuries, multicellular organisms have lived in symbiosis with microorganisms. The interaction with microorganisms has been shown to be very beneficial for humans and animals. During a natural birth, the initial inoculation with bacteria occurs when the neonate passes through the birth canal. Colostrum and milk intake are associated with the acquisition of a healthy gut flora. However, little is known about the microbial composition of bovine colostrum and the possible beneficial effects for the neonatal calf. In this prospective cohort study, the microbial composition of first-milking colostrum was analyzed in 62 Holstein Friesian (HF) and 46 Belgian Blue (BB) cows by performing amplicon sequencing of the bacterial V3–V4 region of the 16S rRNA gene. Calves received, 3 times, 2 L of their dam's colostrum within 24 h after birth. Associations between colostral microbial composition and its IgG concentration, as well as each calf's serum IgG levels, were analyzed. Colostrum samples were dominated by the phyla Proteobacteria, Firmicutes, Bacteroidetes, and Actinobacteria. The 10 most abundant genera in the complete data set were Acinetobacter (16.2%), Pseudomonas (15.1%), a genus belonging to the Enterobacteriaceae family (4.9%), Lactococcus (4.0%), Chryseobacterium (3.9%), Staphylococcus (3.6%), Proteus (1.9%), Streptococcus (1.8%), Enterococcus (1.7%), and Enhydrobacter (1.5%). The remaining genera (other than these top 10) accounted for 36.5% of the counts, and another 8.7% were unidentified. Bacterial diversity differed significantly between HF and BB samples. Within each breed, several genera were found to be differentially abundant between colostrum of different quality. Moreover, in HF, the bacterial composition of colostrum leading to low serum IgG levels in the calf differed from that of colostrum leading to high serum IgG levels. Results of the present study indicate that the microbes present in colostrum are associated with transfer of passive immunity in neonatal calves.     

番茄溃疡病菌的环介导等温核酸扩增技术

目的 建立番茄溃疡病菌的环介导等温核酸扩增技术检测方法。方法 应用环介导等温核酸扩增技术(LAMP)对番茄溃疡病菌的16S rRNA特异性基因进行扩增, 采用4对引物识别目的片段的6个特异性区域, 62 ℃恒温1 h完成扩增。结果 设计的引物与对照菌皱纹假单胞菌、茄假单胞菌、丁香假单胞菌番茄致病变种都没有扩增反应, 表现了较好的特异性。这些对照菌在茄科蔬菜上易引起类似症状。结论 LAMP检测程序便捷, 所需设备简单, 其结果可以通过肉眼观察来判断, 比常规PCR灵敏且能更早得到反应结果, 因此该技术具有更大的优势。     

Biochemical and molecular characterization of novel PAH-degrading bacteria isolated from polluted soil and sludge

Polycyclic aromatic hydrocarbons (PAHs) containing more than three rings are mainly less biodegradable. Therefore, the isolation of PAHs-degrading bacteria is of great importance to be augmented for bioremediation of polluted sites with PAHs. PAHs-degrading bacteria were isolated from contaminated sites of an oil refinery. The strains were confirmed by biochemical tests and 16S rRNA, which were Stenotrophomonas maltophilia (two strains), Thermomonas koreensis (three strains), Achromobacter (two strains), Pseudomonas stutzeri (one strain), Azospirillum brasilense (one strain) and Brevibacillus brevis (one strain). The isolate strains can be applied as a bacterial consortium for purification of polluted soil with high levels of PAHs.     

The assessment of compositional changes in Nimonic PE16 by convergent beam electron diffraction

Lattice parameter changes can be detected by the use of a previously established technique which is based upon computer simulation of HOLZ patterns. This simulation technique is then applied to two precipitation phenomena in Nimonic PE16. Firstly, the growth of gamma prime, γ, precipitates from a solid solution is monitored via the decrease in lattice parameter of the parent phase, and secondly the lattice parameter of coarsened, overaged γ is measured for precipitates sited both at grain boundaries and within grains. The variations thus detected between intergranular and intragranular precipitates are attributed to changes in the Ti/Al ratio due to preferential γ coarsening at the grain boundary. The very subtle compositional changes inferred (～1 at. % Ti) would have been very difficult to establish by chemical analysis, but can be easily measured by convergent beam electron diffraction.     

高压分离器壳体内壁堆焊工艺的确定

介绍了加氢中温高压分离器主体材料 16MnR(HIC)板 ,选用国产单层带极堆焊焊带、手工堆焊焊条进行堆焊过程中遇到的问题及解决方法 ,并着重介绍了工艺规范对堆焊层铁素体含量及堆焊质量的影响 ,确定了适当的堆焊工艺规范参数。     

电熔增材制造16MND5钢的低周疲劳特性

摘要：电熔增材是一种新型重型金属3D打印技术,使用该技术制造的16MND5钢是一种新型材料,对其低周疲劳特性进行系统研究,对推动该技术在核电压力容器上的应用具有重要的指导意义。对电熔增材制造16MND5钢进行了低周疲劳试验研究,试验温度为室温和350℃,采用轴向总应变控制方式,应变比R=-1,应变范围±0.2%～±0.8%。对试验数据进行拟合计算,获得电熔增材制造16MND5钢的应力 应变曲线、应变-寿命曲线和低周疲劳设计曲线等。采用扫描电子显微镜对疲劳试样断口进行了观察,结果显示电熔增材16MND5钢的低周疲劳断口存在多个裂纹源,裂纹扩展区为一系列相互平等的疲劳条带,扩展区同时存在着蠕变孔洞和二次小裂纹,最终断裂区属于韧性断裂。     

全景视觉态势感知系统的多通道串口通信

串口通信作为传统的通信方式仍然受到广泛应用,本文介绍了基于PIC16F877A单片机、TL16C754异步通信芯片和MAX485芯片实现异步通信串口扩展的整体方案。方案实现了十四个串口同时进行长时间稳定可靠的双向数据通信。通过开展相应的试验,证明了该处理方案的有效性,并在某工程项目中得到应用。     

Quantifying the impact of agricultural technology usage on intra-household time allocation: Empirical evidence from rice farmers in Ghana

The use of improved agricultural technologies that lead to improved productivity, income and food security, could also destabilize intra-household time allocation. Using primary data from 917 rice farmers in Ashanti and Upper East Regions of Ghana, this paper employs a two-stage Bourguignon, Fournier, and Gurgand (BFG) selection bias correction model to quantify the impact of improved rice production technologies on intra-household time allocation. The empirical results indicate that farmers who take up improved rice technologies (fertilizer and improved rice seed) tend to increase labour input in farm work by 13.93 h per week. This has implications for the amount of time available for domestic work and leisure, especially for women in typical rice farming household. The design and development of technological innovations in the agricultural sector should take serious account of the domestic workload of women in farming communities to improve intensity and sustainability of use for both men and women.     

500kV 长线路故障测距仪的 16 位微机系统

介绍了用８０８６ＣＰＵ设计的故障测距仪的１６位微机系统。该系统具有程序、数据空间大的特点,能支持复杂的以解长线方程为基础的长线故障测距软件。用ＡＳＭ８６和Ｃ语言编写,具有双精度浮点数和双曲复函数及复杂数学运算的软件可以固化在该系统的ＥＰＲＯＭ中,在无操作系统支持的环境下运行。