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排序方式: 共有830条查询结果,搜索用时 15 毫秒
781.
S Frosch A Gruber C Jones S Myers E Noel A Westerlund T Zavisin 《Canadian Metallurgical Quarterly》1997,11(12):891-906
This study was conducted to identify the long term effects of traumatic brain injury (TBI) on the roles of caregivers. The subjects consisted of 155 caregivers of survivors with TBI who were randomly selected from 15 midwestern state brain injury association databases. A questionnaire was developed by the researchers to determine factors affecting role changes of caregivers. The Role Checklist, by Barris, Oakley and Kielhofner, was also included with the questionnaire. Both were mailed to each selected caregiver and used for data gathering. The data obtained were analysed to determine existing trends in the data. Graphs were utilized to depict the trends that was identified. The following trends and conclusions established by this research include: (a) behavioural effects of the survivor with a TBI are associated with the number of role changes experienced by caregivers; (b) participation in support systems is associated with the number of role changes experienced by caregivers; and (c) caregivers who care for a person with a TBI in the home will show a larger number of role changes than those who do not provide direct care for a person with a TBI. 相似文献
782.
Gruber M. Ken-Yuh Hsu 《IEEE transactions on pattern analysis and machine intelligence》1997,19(2):136-139
In this paper the effects of noise with nonzero mean on existing moment-based image normalization methods are studied. Several modifications to reduce noise sensitivity are presented and tested. They involve nonlinear mapping and fractional- and negative-order moments 相似文献
783.
Pfistner C. Weber R. Weber H.P. Merazzi S. Gruber R. 《Quantum Electronics, IEEE Journal of》1994,30(7):1605-1615
The thermally induced beam distortions in end-pumped Nd:YAG, Nd:GSGG, and Nd:YLF rods were analyzed and the influence of edge- and face-cooling was investigated. The distributions of temperature, stress, and strain in the crystals were calculated by finite element analysis. Based on these data, the space-resolved changes of the refractive index were determined considering thermal dispersion, surface deformation, and strain-induced birefringence. The resulting optical path difference for one round-trip in the end-pumped rods was integrated numerically. For each rod, the induced thermal lens was determined over the extent of the pump spot radius. The calculations of the optical path difference were experimentally confirmed by investigations using a modified Twyman-Green interferometer with a polarized HeNe probe beam at 633 nm under lasing and nonlasing conditions 相似文献
784.
Estradiol-induced synthesis of vitellogenin. III. The isolation and characterization of vitellogenin messenger RNA from avian liver 总被引:3,自引:0,他引:3
G Ab WG Roskam J Dijkstra J Mulder M Willems A Van der Ende M Gruber 《Canadian Metallurgical Quarterly》1976,454(1):67-78
The messenger RNA of the hormone-induced protein vitellogenin was isolated from the liver of estrogen-treated roosters. Starting from total polysomal RNA, the vitellogenin messenger was purified 67-fold by oligo (dT)-cellulose chromatography and sizing on a sucrose gradient. The messenger was translated in vitro into a 170 000 dalton polypeptide chain, having the immunochemical characteristics of vitellogenin. From electrophoretic and immunochemical analysis of the in vitro product of translation at least 63% of the messenger activity of the RNA preparation could be attributed to vitellogenin mRNA. Gel electrophoresis of the most purified fraction revealed residual contamination with the larger ribosomal RNA species. The molecular weight of the messenger RNA molecule, obtained by contour length measurements in the electron microscope, lies between 2.5 - 10(6) and 2.8 - 10(6). 相似文献
785.
Hormonal control of vitellogenin synthesis in avian liver 总被引:3,自引:0,他引:3
Estradiol induces the synthesis of vitellogenin in the avian liver. We describe the precursor-product relationship between vitellogenin and the yolk proteins phosvitin and lipovitellin. The high rate of vitellogenin synthesis is a consequence of the accumulation of a stable messenger RNA. We suggest that estradiol acts at the level of the genome by opening a hitherto non-transcribed gene. 相似文献
786.
Anti-Lu 14 has been found in the serum of a gravida 2 pregnant woman who had not been given any blood transfusions. Her husband is Lu:14 but otherwise of common Lutheran blood type. Maternal immunization probably occurred during the first pregnancy. The second child did not inherit the father's Lu14 gene and was not affected by the maternal antibody. 相似文献
787.
788.
Strategic knowledge is used by an agent to decide what action to perform next, where actions have consequences external to the agent. This article presents a computer-mediated method for acquiring strategic knowledge. The general knowledge acquisition problem and the special difficulties of acquiring strategic knowledge are analyzed in terms of representation mismatch: the difference between the form in which knowledge is available from the world and the form required for knowledge systems. ASK is an interactive knowledge acquisition tool that elicits strategic knowledge from people in the form of justifications for action choices and generates strategy rules that operationalize and generalize the expert's advice. The basic approach is demonstrated with a human–computer dialog in which ASK acquires strategic knowledge for medical diagnosis and treatment. The rationale for and consequences of specific design decisions in ASK are analyzed, and the scope of applicability and limitations of the approach are assessed. The paper concludes by discussing the contribution of knowledge representation to automated knowledge acquisition. 相似文献
789.
790.
It is shown, how the existing estimates by Long, Trick and Chang of upper bounds on limit-cycles in second order digital filters caused by quantization effects can be improved. Two new estimates of upper bounds are presented, that improve existing estimates by up to 50% dependent on the pole locations of the filter. The theoretical results are illustrated by numerous examples. 相似文献