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1.
《Journal of dairy science》2022,105(3):2439-2452
Bias in dairy genetic evaluations, when it exists, has to be understood and properly addressed. The origin of biases is not always clear. We analyzed 40 yr of records from the Lacaune dairy sheep breeding program to evaluate the extent of bias, assess possible corrections, and emit hypotheses on its origin. The data set included 7 traits (milk yield, fat and protein contents, somatic cell score, teat angle, udder cleft, and udder depth) with records from 600,000 to 5 million depending on the trait, ~1,900,000 animals, and ~5,900 genotyped elite artificial insemination rams. For the ~8% animals with missing sire, we fit 25 unknown parent groups. We used the linear regression method to compare “partial” and “whole” predictions of young rams before and after progeny testing, with 7 cut-off points, and we obtained estimates of their bias, (over)dispersion, and accuracy in early proofs. We tried (1) several scenarios as follows: multiple or single trait, the “official” (routine) evaluation, which is a mixture of both single and multiple trait, and “deletion” of data before 1990; and (2) several models as follows: BLUP and single-step genomic (SSG)BLUP with fixed unknown parent groups or metafounders, where, for metafounders, their relationship matrix gamma was estimated using either a model for inbreeding trend, or base allele frequencies estimated by peeling. The estimate of gamma obtained by modeling the inbreeding trend resulted in an estimated increase of inbreeding, based on markers, faster than the pedigree-based one. The estimated genetic trends were similar for most models and scenarios across all traits, but were shrunken when gamma was estimated by peeling. This was due to shrinking of the estimates of metafounders in the latter case. Across scenarios, all traits showed bias, generally as an overestimate of genetic trend for milk yield and an underestimate for the other traits. As for the slope, it showed overdispersion of estimated breeding values for all traits. Using multiple-trait models slightly reduced the overestimate of genetic trend and the overdispersion, as did including genomic information (i.e., SSGBLUP) when the gamma matrix was estimated by the model for inbreeding trend. However, only deletion of historical data before 1990 resulted in elimination of both kind of biases. The SSGBLUP resulted in more accurate early proofs than BLUP for all traits. We considered that a snowball effect of small errors in each genetic evaluation, combined with selection, may have resulted in biased evaluations. Improving statistical methods reduced some bias but not all, and a simple solution for this data set was to remove historical records. 相似文献
2.
为解决证据组合规则中一票否决和弱决策证据在低冲突情况下出现的反直观推理的现象,提出一种有效折扣证据源的冲突证据合成方法。首先根据证据的信任函数和似然函数求得证据间的相似度,然后求出证据之间的支持程度,并确定折扣因子,最后采用Dempster组合规则合成利用折扣因子修正后的证据源。数值算例分析结果表明,改进后的证据组合方法可以有效地处理证据冲突。 相似文献
3.
Dirk Bühler 《Mauerwerk》2020,24(1):26-36
The Rank construction company and the introduction of brick vaults in Munich after 1945 The construction of vaults without scaffolding with thin bricks has a centuries‐old tradition, particularly in Spain and Italy. Since the beginning of the 19th century, it has been successfully spread mainly on the American double continent. The Rank Brothers construction company in Munich is known to date as one of those construction companies that began building with concrete in its home city very early on. New investigations, which were made possible above all by the provision of archive material by Paul Basiner, now point to an additional focus of this company's work. The architects and engineers of the company had been also able to familiarise themselves with this traditional Spanish brick‐vaulted construction method via the branch office in Spain, which was established from 1911 on. This knowledge was particularly in demand in the years following World War II, when the destroyed vaults had to be rebuilt with simple means and low material consumption. Together with Carl Sattler, who had become acquainted with similar construction methods in Italy, brick vaults were initially used to complete the construction of the Landeszentralbank in Munich. In the following years, Rank was able to provide many buildings in and around Munich with brick vaults. It was not until the 1960s that this construction technique went out of fashion and was thus somewhat forgotten. 相似文献
4.
Merlin G. Butler Syed K. Rafi Ann M. Manzardo 《International journal of molecular sciences》2015,16(3):6464-6495
Recently, autism-related research has focused on the identification of various genes and disturbed pathways causing the genetically heterogeneous group of autism spectrum disorders (ASD). The list of autism-related genes has significantly increased due to better awareness with advances in genetic technology and expanding searchable genomic databases. We compiled a master list of known and clinically relevant autism spectrum disorder genes identified with supporting evidence from peer-reviewed medical literature sources by searching key words related to autism and genetics and from authoritative autism-related public access websites, such as the Simons Foundation Autism Research Institute autism genomic database dedicated to gene discovery and characterization. Our list consists of 792 genes arranged in alphabetical order in tabular form with gene symbols placed on high-resolution human chromosome ideograms, thereby enabling clinical and laboratory geneticists and genetic counsellors to access convenient visual images of the location and distribution of ASD genes. Meaningful correlations of the observed phenotype in patients with suspected/confirmed ASD gene(s) at the chromosome region or breakpoint band site can be made to inform diagnosis and gene-based personalized care and provide genetic counselling for families. 相似文献
5.
玉林胜果寺古代冶铸遗址位于广西玉林市兴业县龙安镇杨前村胜果寺附近的丘陵,面积超过2 000m~2。采用扫描电镜及能谱分析(SEM-EDS)、金相和矿相等研究方法,对胜果寺古代冶铸遗址的5个冶金遗物炉渣样品进行成分和显微组织分析检测。结果表明,该遗址为生铁冶铸遗址,炼渣属锰硅铝系高锰炉渣。冶炼产品除供本地铸锅等生产生活用品外,大量运往韶州涔水场浸铜。 相似文献
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7.
山西省太原市西南的蒙山南麓风峪沟沿线遍布众多石碹窑洞,形成了具有明显地域性特点的传统建筑群。通过对其中周家庄古村的调查研究,将古村内石碹窑洞群中具有代表性的周家粮铺院作为研究对象,以此院落的建筑布局、内部空间营造及建造技术特点为主要内容,对该地区建筑遗存信息和文献资料进行整理研究,对建筑群体进行实地勘查及计算机建模,为山西传统村落的保护和可持续发展提供合理依据。 相似文献
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9.
Energy Conservation &Environmental Protection of Waste Rubber Compr ehensive Utilization Re-upgraded
"Even though the realized profit of 38 key member enterprises increased by 14.96% in the first 7 months of this year, we shall be acutely aware of the big gap from the resource-saving and eco-friendly enterprises as the economic benefit of the industry is increasing. In particular, the environmental protection situation is severe in the current industry, so environmental protection becomes a historical mission in waste rubber comprehensive utilization industry." 相似文献
10.
Xavier Kurten (?–1840) was a Prussian landscape gardener who worked for the Savoy family in the Piedmont region of Italy in the first half of the nineteenth century. He designed or redesigned all royal parks, creating a specific style based on the English naturalistic garden approach. This research was performed with the aim of investigating the development of the English landscape garden in Italy. Historical documents relating to Kurten’s biography and his work in Piedmont, including plans, were collected and analysed. We analyse and discuss the features that characterised his work: the relationship between the landscape—garden—house, the path system, the use of water, the vegetation, and the garden as a productive landscape. Kurten’s style is compared with the projects of William Kent and Lancelot ‘Capability’ Brown. 相似文献