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31.
《Journal of dairy science》2022,105(3):2408-2425
Reggiana and Modenese are autochthonous cattle breeds, reared in the North of Italy, that can be mainly distinguished for their standard coat color (Reggiana is red, whereas Modenese is white with some pale gray shades). Almost all milk produced by these breeds is transformed into 2 mono-breed branded Parmigiano-Reggiano cheeses, from which farmers receive the economic incomes needed for the sustainable conservation of these animal genetic resources. After the setting up of their herd books in 1960s, these breeds experienced a strong reduction in the population size that was subsequently reverted starting in the 1990s (Reggiana) or more recently (Modenese) reaching at present a total of about 2,800 and 500 registered cows, respectively. Due to the small population size of these breeds, inbreeding is a very important cause of concern for their conservation programs. Inbreeding is traditionally estimated using pedigree data, which are summarized in an inbreeding coefficient calculated at the individual level (FPED). However, incompleteness of pedigree information and registration errors can affect the effectiveness of conservation strategies. High-throughput SNP genotyping platforms allow investigation of inbreeding using genome information that can overcome the limits of pedigree data. Several approaches have been proposed to estimate genomic inbreeding, with the use of runs of homozygosity (ROH) considered to be the more appropriate. In this study, several pedigree and genomic inbreeding parameters, calculated using the whole herd book populations or considering genotyping information (GeneSeek GGP Bovine 150K) from 1,684 Reggiana cattle and 323 Modenese cattle, were compared. Average inbreeding values per year were used to calculate effective population size. Reggiana breed had generally lower genomic inbreeding values than Modenese breed. The low correlation between pedigree-based and genomic-based parameters (ranging from 0.187 to 0.195 and 0.319 to 0.323 in the Reggiana and Modenese breeds, respectively) reflected the common problems of local populations in which pedigree records are not complete. The high proportion of short ROH over the total number of ROH indicates no major recent inbreeding events in both breeds. ROH islands spread over the genome of the 2 breeds (15 in Reggiana and 14 in Modenese) identified several signatures of selection. Some of these included genes affecting milk production traits, stature, body conformation traits (with a main ROH island in both breeds on BTA6 containing the ABCG2, NCAPG, and LCORL genes) and coat color (on BTA13 in Modenese containing the ASIP gene). In conclusion, this work provides an extensive comparative analysis of pedigree and genomic inbreeding parameters and relevant genomic information that will be useful in the conservation strategies of these 2 iconic local cattle breeds. 相似文献
32.
动态特性是航天电磁继电器的重要特征之一,在继电器的生产与研究过程中需要进行测试与分析。现有条件下,动态特性测试系统测得的结果以文本和图像形式保存在本地计算机中,研究人员需采用人工作业的方式对文本文件和图像文件进行分析。针对上述问题,本文设计了一套基于WinForm的动态特性测试系统软件,具体分为客户端软件与服务器软件,双方基于Socket多线程通信实现文本文件和图像文件传输的及时性与可靠性,突破了研究人员本地作业的空间局限性;基于双缓冲技术绘制文本文件的曲线图,加强对测试结果的直观性分析;基于图像调用与局部放大技术,实现对图像的有效处理与显示。测试结果表明,所设计的系统软件运行稳定,分析与显示结果直观准确,具有较高的使用价值。 相似文献
33.
AbstractIn this paper, the effects of hygrothermal conditions on various behaviors, such as bending, free vibration, mechanical and thermal buckling, of exponentially graded microplates lying on two-parameter elastic foundations are investigated. The trigonometric four-variable plate theory incorporated to the modified couple stress theory (MCST) is employed to derive the equations of motion. The present MCST contains an internal material length scale parameter, thus it can capture the size effect. The microplate is assumed to be subjected to a temperature rise and moisture concentration which are varied linearly through the thickness of the plate. Based on an exponential law, the material properties of the microplate are graded only in z direction. The equations of motion are solved analytically to obtain the displacements, stresses, eigenfrequencies and critical buckling load and temperature of the microplates. The present results are validated by comparing them with those previously published. The numerical examples reveal that considering the size effect and/or the elastic foundations leads to an increment in plate stiffness and thereby leads to a decrement in the deflection and an increment in eigenfrequency and buckling loads. It is also shown that the size effect is negligible for the thicker plate. 相似文献
34.
The effects of local body cooling on thermal comfort and sleep quality in a hot environment were investigated in an experiment with 16 male subjects. Sleep quality was evaluated subjectively, using questionnaires completed in the morning, and objectively, by analysis of electroencephalogram (EEG) signals that were continuously monitored during the sleeping period. Compared with no cooling, the largest improvement in thermal comfort and sleep quality was observed when the back and head (neck) were both cooled at a room temperature of 32°C. Back cooling alone also improved thermal comfort and sleep quality, although the effects were less than when cooling both back and head (neck). Mean sleep efficiency was improved from 84.6% in the no cooling condition to 95.3% and 92.8%, respectively, in these conditions, indicating good sleep quality. Head (neck) cooling alone slightly improved thermal comfort and subjective sleep quality and increased Stage N3 sleep, but did not otherwise improve sleep quality. The results show that local cooling applied to large body sections (back and head) could effectively maintain good sleep and improve thermal comfort in a hot environment. 相似文献
35.
无线传感器网络中广播通信的安全协议设计 总被引:1,自引:1,他引:0
摘 要:广播通信安全是无线传感器网络设计中的重要问题。本文首先分析了无线传感器网络中广播通信的特点、所需要解决的关键安全问题和以及安全协议设计原则,随后提出了基于公钥算法的全局广播通信安全协议和基于单向密钥链的局部广播通信安全协议,较好地实现了广播通信的可靠性认证、完整性和时效性。同时从性能分析看,本文方案只为传感节点引入了少量的通信负荷、能量消耗和存储空间。 相似文献
36.
本文对矿井多级机站可控式通风系统研究工作作总结,并列举了工业应用情况,说明多级机站可控式通风技术是一种节能、易于风量痫节等特点的新技术。 相似文献
37.
38.
应用CFD软件Fluent6 .0模拟圆管的内部流场以解决其局部损失问题 ,与现有的解析和实验结果进行了比较 ,并显示了圆管内部流动的流线图。结果显示 ,应用Fluent6 .0模拟圆管内部流场是可靠的。为Fluent6 .0软件在流体理论研究中的应用提供了参考。 相似文献
39.
通过对现有矿井降温技术的分析,研究了一种适合采掘工作面布置特点局部降温装置.该矿用局部供冷装置主要由设有内部换热盘管的储冰车、安装有潜水泵的储水车及空冷器组成.分析了该装置的主要特点及供冷工艺流程,给出了该装置的设计计算依据及相关设计参数;设计确定了储冰箱内换热盘管温降5℃、不同管内水流速下的管程。确定了不同规格矿车、不同管内水流速下的单管程回路根数;确定了不同条件下的储冷量、供冷量及可供冷时间及对应条件下的盘管水阻力;为该局部供冷装置的实施提供了理论依据.图1,表4,参9. 相似文献
40.
近年来,在土地违法案件中,地方政府违法占地问题比较严重。本文从立法、行政、司法等方面分析地方政府土地违法现象产生的原因,同时指出其造成的后果,在此基础上试图寻找出治理地方政府土地违法现象的对策,为加强土地管理工作提供参考。 相似文献