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2.
M Furuta K Hayakawa S Katano Y Saito Y Nakayama T Takahashi R Imai T Ebara N Mitsuhashi H Niibe 《Canadian Metallurgical Quarterly》1996,26(2):95-98
Vaccination with peptides that induce a specific immune response is a potential prophylactic or therapeutic strategy against viral infections and tumors. Because of the extensive polymorphism of the HLA loci, synthetic peptide vaccines must consist of a cocktail of peptides that bind specifically to different HLA molecules. Such cocktails should be optimized for the target population as each population has its specific HLA gene frequencies. To achieve maximum population coverage with a minimum number of peptides, information is needed on the ranking of the most frequent HLA phenotypes. We introduce the minimal phenotype panel, which is the smallest combination of HLA antigens selected so that the proportion of individuals in a population that express at least one of the antigens in the panel exceeds a desired minimum value. We developed a method for assembling minimal phenotype panels based on known HLA class I gene frequencies. We give an example based on a set of 2446 well-defined HLA-typed, random, healthy, unrelated, Dutch Caucasoid individuals. In addition, we discuss the possibility of assembling minimal phenotype panels based on two-locus haplotypes, which enables the assembly of phenotype panels from the antigens of both loci. 相似文献
3.
Takahiro Hoshino 《Computational statistics & data analysis》2008,52(3):1413-1429
The estimation of the differences among groups in observational studies is frequently inaccurate owing to a bias caused by differences in the distributions of covariates. In order to estimate the average treatment effects when the treatment variable is binary, Rosenbaum and Rubin [1983. The central role of the propensity score in observational studies for causal effects. Biometrika 70, 41-55] proposed an adjustment method for pre-treatment variables using propensity scores. Imbens [2000. The role of the propensity score in estimating dose-response functions. Biometrika 87, 706-710] extended the propensity score methodology for estimation of average treatment effects with multivalued treatments.However, these studies focused only on estimating the marginal mean structure. In many substantive sciences such as the biological and social sciences, a general estimation method is required to deal with more complex analyses other than regression, such as testing group differences on latent variables. For latent variable models, the EM algorithm or the traditional Monte Carlo methods are necessary. However, in propensity score adjustment, these methods cannot be used because the full distribution is not specified.In this paper, we propose a quasi-Bayesian estimation method for general parametric models that integrate out the distributions of covariates using propensity scores. Although the proposed Bayes estimates are shown to be consistent, they can be calculated by existing Markov chain Monte Carlo methods such as Gibbs sampler. The proposed method is useful to estimate parameters in latent variable models, while the previous methods were unable to provide valid estimates for complex models such as latent variable models.We also illustrated the procedure using the data obtained from the US National Longitudinal Survey of Children and Youth (NLSY1979-2002) for estimating the effect of maternal smoking during pregnancy on the development of the child's cognitive functioning. 相似文献
4.
A cryogenic power cable is expected to be capable of carrying bulk power as a main transmission line in a future metropolitan electric power system. It is important to establish a strategy of how to sustain power supply when such a highly densified power supply route trips from the network due to contingency. It is proposed here that the bulk power transmitted by the cryogenic cable could be distributed into the parallel conventional transmission lines by suitable circuit breaker operations in the system. In this process, power-flow routes are forced to be changed with a remarkable modification in the system configuration. In this paper, the power swings associated with the large power-flow change following contingent faults are analyzed by means of a transient network analyzer. It is found that the proposed system modification could be realized without any harmful power swing if the parameters in generators as well as in control devices have conventional magnitudes. It is shown also by simulations that the margin to occurrence in an unstable power swing is left sufficient even if the parameters deviate somewhat from the present magnitudes. 相似文献
5.
Cold-rolling texture and partially recrystallized texture of polycrystalline 3 pct Si-Fe were investigated using high-resolution
electron backscattered diffraction (EBSD) method. From the measurement on a deformed grain with {211}〈011〉∼{111}〈011〉 orientations,
deformation bands with {12 4 1}〈014〉 orientation were found. It turned out that the orientation rotation relationship between
deformation bands and surrounding deformed grain can be explained by the activation of the slip system, which has a common
slip plane with an adjacent grain. Oriented nucleation of recrystallized grains with {12 4 1}〈014〉 orientation was observed
in a deformed grain with {211}〈011〉∼{111}〈011〉 orientation. Exactly the same orientation relationship that was observed between
deformed grain and the deformation bands was also observed between the deformed grain and the recrystallized grain. A hypothesis
that recrystallization nuclei are generated directly from the deformation bands formed by an activation of the slip system
that has a common slip plane of neighboring deformed grains was proposed from the present experimental results. 相似文献
6.
Student O. Z. Rusyn B. P. Kysil' B. V. Kobasyar M. I. Stakhiv T. P. Markov A. D. 《Materials Science》2003,39(1):17-24
We give a quantitative estimate of changes in the structure of 15Kh2MFA steel after its long-term exposure to the combined action of high temperature, tensile stresses, and hydrogen as the factors of degradation of this steel under conditions of oil hydrocracking. Under laboratory conditions, we study the effect of high-temperature hydrogen degradation of 15Kh2MFA heat-resistant steel on changes in the quantitative characteristics of its structural elements, in particular, in the dimension and average distance between carbides as well as in their orientation from one grain to another. Algorithms for the solution of the formulated problems are described, and the possibilities of proposed approaches for the quantitative automatic processing of metallographic images are shown. 相似文献
7.
The distribution ratios of Fe and B between molten Fe–B alloy and molten Ag were measured at temperatures between 1573 and 1923 K. Also, distribution ratios of Fe and B between molten Fe–B–Csatd. alloys and molten Ag were measured at 1873 K. It was found that the excess Gibbs free energy of mixing in molten Fe–B and Fe–B–C alloys can be expressed by utilizing the Redlich–Kister polynomial. The activity curves of the elements in molten Fe–B alloy and Fe–B–C alloy were estimated. 相似文献
8.
9.
无线数据通信网发展趋势 总被引:1,自引:0,他引:1
无线数据通信具有两大发展趋势,即低速的广域移动数据网及高速的局域无线数据网。本文介绍了其技术特点、应用情况和市场前景,分析了无线数据通信传输技术、网络结构和媒质接入控制等问题。 相似文献
10.
The islets of Langerhans are richly innervated, and an inhibitory effect on insulin secretion, mediated through alpha 2-adrenergic receptors, appears to be an important physiological neural modulator of beta-cell function. An alpha 2-receptor was cloned from isolated newborn rat islets using a polymerase chain reaction (PCR) approach. This receptor was shown by sequencing to be a new rat alpha 2-receptor very similar to the human alpha 2-C2 receptor. No other alpha 2-receptor subtype was identified in normal islets by the PCR using alpha 2-receptor primers. This was also the only alpha 2-receptor subtype present in the exocrine pancreas and liver. In contrast, in the beta-cell line, beta TC3, the alpha 2-C2 receptor was not detected, but the alpha 2-C4 and alpha 2-C10 receptor subtypes were detected. It is suggested that the alpha 2-C2 subtype may be the principal alpha 2-receptor mediating inhibitory autonomic nervous system activity in the gastrointestinal tract. A comparison of the rat islet, pancreas, and liver alpha 2-receptor sequences reported here with previously reported alpha 2-receptor sequences indicates that the rat islet alpha 2-receptor is not the rat alpha 2-C2 homologue previously denoted as RNG alpha 2, but is a new, fourth rat subtype with an even higher similarity to the human alpha 2-C2 receptor. 相似文献