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1.
一种适合于网络专家系统的通用理论(英文) 总被引:1,自引:0,他引:1
描述运用于工业自动化的一种自适应自学习方法。基于此方法,Aptronix公司开发出一套通用软件工具-STIMTM,并应用于不同工业领域。STIM可用于构造各类专家系统。基于因素空间理论,STIM具有一系列独特之处,比如自动化、自学习,以及自翻译。如果与因特网,嵌入式控制器以及可编程逻辑控制器等结合使用,STIM则成为一个十分有效的工具,可应用于远程连通与控制、模式识别、机器故障诊断,以及自动化加工过程中的传感器数据融合 相似文献
2.
Liu F Thirumangalathu S Gallant NM Yang SH Stoick-Cooper CL Reddy ST Andl T Taketo MM Dlugosz AA Moon RT Barlow LA Millar SE 《Nature genetics》2007,39(1):106-112
Fungiform taste papillae form a regular array on the dorsal tongue. Taste buds arise from papilla epithelium and, unusually for epithelial derivatives, synapse with neurons, release neurotransmitters and generate receptor and action potentials. Despite the importance of taste as one of our five senses, genetic analyses of taste papilla and bud development are lacking. We demonstrate that Wnt-beta-catenin signaling is activated in developing fungiform placodes and taste bud cells. A dominant stabilizing mutation of epithelial beta-catenin causes massive overproduction of enlarged fungiform papillae and taste buds. Likewise, genetic deletion of epithelial beta-catenin or inhibition of Wnt-beta-catenin signaling by ectopic dickkopf1 (Dkk1) blocks initiation of fungiform papilla morphogenesis. Ectopic papillae are innervated in the stabilizing beta-catenin mutant, whereas ectopic Dkk1 causes absence of lingual epithelial innervation. Thus, Wnt-beta-catenin signaling is critical for fungiform papilla and taste bud development. Altered regulation of this pathway may underlie evolutionary changes in taste papilla patterning. 相似文献
3.
Dunham A Matthews LH Burton J Ashurst JL Howe KL Ashcroft KJ Beare DM Burford DC Hunt SE Griffiths-Jones S Jones MC Keenan SJ Oliver K Scott CE Ainscough R Almeida JP Ambrose KD Andrews DT Ashwell RI Babbage AK Bagguley CL Bailey J Bannerjee R Barlow KF Bates K Beasley H Bird CP Bray-Allen S Brown AJ Brown JY Burrill W Carder C Carter NP Chapman JC Clamp ME Clark SY Clarke G Clee CM Clegg SC Cobley V Collins JE Corby N Coville GJ Deloukas P Dhami P Dunham I Dunn M Earthrowl ME Ellington AG 《Nature》2004,428(6982):522-528
Chromosome 13 is the largest acrocentric human chromosome. It carries genes involved in cancer including the breast cancer type 2 (BRCA2) and retinoblastoma (RB1) genes, is frequently rearranged in B-cell chronic lymphocytic leukaemia, and contains the DAOA locus associated with bipolar disorder and schizophrenia. We describe completion and analysis of 95.5 megabases (Mb) of sequence from chromosome 13, which contains 633 genes and 296 pseudogenes. We estimate that more than 95.4% of the protein-coding genes of this chromosome have been identified, on the basis of comparison with other vertebrate genome sequences. Additionally, 105 putative non-coding RNA genes were found. Chromosome 13 has one of the lowest gene densities (6.5 genes per Mb) among human chromosomes, and contains a central region of 38 Mb where the gene density drops to only 3.1 genes per Mb. 相似文献
4.
F Kemper C J?ger L B F M Waters Th Henning F J Molster M J Barlow T Lim A de Koter 《Nature》2002,415(6869):295-297
Carbonates on large Solar System bodies like Earth and Mars (the latter represented by the meteorite ALH84001) form through the weathering of silicates in a watery (CO3)2- solution. The presence of carbonates in interplanetary dust particles and asteroids (again, represented by meteorites) is not completely understood, but has been attributed to aqueous alteration on a large parent body, which was subsequently shattered into smaller pieces. Despite efforts, the presence of carbonates outside the Solar System has hitherto not been established. Here we report the discovery of the carbonates calcite and dolomite in the dust shells of evolved stars, where the conditions are too primitive for the formation of large parent bodies with liquid water. These carbonates, therefore, are not formed by aqueous alteration, but perhaps through processes on the surfaces of dust or ice grains or gas phase condensation. The presence of carbonates which did not form by aqueous alteration suggests that some of the carbonates found in Solar System bodies no longer provide direct evidence that liquid water was present on large parent bodies early in the history of the Solar System. 相似文献
5.
An ICE pattern crystallizes 总被引:3,自引:0,他引:3
6.
Loss of neuropathy target esterase in mice links organophosphate exposure to hyperactivity 总被引:13,自引:0,他引:13
Neuropathy target esterase (NTE) is involved in neural development and is the target for neurodegeneration induced by selected organophosphorus pesticides and chemical warfare agents. We generated mice with disruptions in Nte, the gene encoding NTE. Nte(-/-) mice die after embryonic day 8, and Nte(+/-) mice have lower activity of Nte in the brain and higher mortality when exposed to the Nte-inhibiting compound ethyl octylphosphonofluoridate (EOPF) than do wild-type mice. Nte(+/-) and wild-type mice treated with 1 mg per kg of body weight of EOPF have elevated motor activity, showing that even minor reduction of Nte activity leads to hyperactivity. These studies show that genetic or chemical reduction of Nte activity results in a neurological phenotype of hyperactivity in mammals and indicate that EOPF toxicity occurs directly through inhibition of Nte without the requirement for Nte gain of function or aging. 相似文献
7.
<中国科技术语>编辑部:
收到你们的<中国科技术语>第一期,非常感谢.读了这期文章,深感不仅是刊物名称的改动,也看到内容的拓宽与提高. 相似文献
8.
为提高高分辨雷达的检测性能,提出了一种高斯杂波背景下距离扩展目标的模糊检测方法。该方法采用模糊恒虚警率(constant false alarm rate, CFAR)检测器代替传统的二进制CFAR检测器,将距离单元值转换成映射到虚警空间的模糊隶属函数值,然后采用模糊积累准则进行积累,得到检测统计量。研究了模糊代数积、模糊代数和两种积累准则,推导出这两种方法虚警概率的数学解析式。仿真结果表明,高斯杂波背景下模糊代数积积累较双门限二进制积累可获得近2 dB的性能改善。同时,模糊检测方法只采用单个检测门限,具有易于调节的优点。 相似文献
9.
Genes encoding types I, II and III collagens (fibrillar collagens) contain many discrete-size exons, most of them 54 base pairs (bp) long, in addition to the 45-, 99-, 108- and 162-bp exons. It has been suggested that these collagen genes evolved from an ancestral coding unit of 54 bp. Type IV collagen is a specific component of basement membranes and contains two genetically distinct polypeptides, the alpha 1(IV) and alpha 2(IV) chains. It differs from the types I-III collagens in that it contains interruptions in the Gly-X-Y repeat sequence and does not form ordered fibrillar structures. We have isolated complementary DNA and genomic clones for the mouse alpha 2(IV) collagen chain and here characterize 64-, 123- and 182-bp exons in the Gly-X-Y coding domain of the gene. The data suggest that the alpha 2(IV) collagen gene may have evolved differently from those encoding the fibrillar collagens. 相似文献
10.
利用组织切片技术,结合外观特征,在光学水平对江苏南通地区第一次排卵后18天内(即卵巢的二次发育)的中华绒螯蟹的卵巢发育进行组织学和细胞学的观察研究.本实验可以观察到卵细胞发育的四个不同时期:初级卵母细胞小生长期、初级卵母细胞大生长期、成熟期以及退化时期的卵细胞.排卵后的卵巢在营养贫乏的情况下,出现直接退化现象;而在营养丰富的情况下,处于大生长前期的卵细胞则会迅速生长,为二次排卵做好准备. 相似文献