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Toru Watanabe Timothy A. Bartrand Mark H. Weir Tatsuo Omura Charles N. Haas 《Risk analysis》2010,30(7):1129-1138
In order to develop a dose‐response model for SARS coronavirus (SARS‐CoV), the pooled data sets for infection of transgenic mice susceptible to SARS‐CoV and infection of mice with murine hepatitis virus strain 1, which may be a clinically relevant model of SARS, were fit to beta‐Poisson and exponential models with the maximum likelihood method. The exponential model (k= 4.1 × l02) could describe the dose‐response relationship of the pooled data sets. The beta‐Poisson model did not provide a statistically significant improvement in fit. With the exponential model, the infectivity of SARS‐CoV was calculated and compared with those of other coronaviruses. The does of SARS‐CoV corresponding to 10% and 50% responses (illness) were estimated at 43 and 280 PFU, respectively. Its estimated infectivity was comparable to that of HCoV‐229E, known as an agent of human common cold, and also similar to those of some animal coronaviruses belonging to the same genetic group. Moreover, the exponential model was applied to the analysis of the epidemiological data of SARS outbreak that occurred at an apartment complex in Hong Kong in 2003. The estimated dose of SARS‐CoV for apartment residents during the outbreak, which was back‐calculated from the reported number of cases, ranged from 16 to 160 PFU/person, depending on the floor. The exponential model developed here is the sole dose‐response model for SARS‐CoV at the present and would enable us to understand the possibility for reemergence of SARS. 相似文献
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Linda A. Camras Harriet Oster Roger Bakeman Zhaolan Meng Tatsuo Ujiie Joseph J. Campos 《Infancy》2007,11(2):131-155
Do infants show distinct negative facial expressions for different negative emotions? To address this question, European American, Chinese, and Japanese 11‐month‐olds were videotaped during procedures designed to elicit mild anger or frustration and fear. Facial behavior was coded using Baby FACS, an anatomically based scoring system. Infants' nonfacial behavior differed across procedures, suggesting that the target emotions were successfully elicited. However evidence for distinct emotion‐specific facial configurations corresponding to fear versus anger was not obtained. Although facial responses were largely similar across cultures, some differences also were observed. Results are discussed in terms of functionalist and dynamical systems approaches to emotion and emotional expression. 相似文献
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Reported data sets on infection of volunteers challenged with wild-type influenza A virus at graded doses are few. Alternatively, we aimed at developing a dose-response assessment for this virus based on the data sets for its live attenuated reassortants. Eleven data sets for live attenuated reassortants that were fit to beta-Poisson and exponential dose-response models. Dose-response relationships for those reassortants were characterized by pooling analysis of the data sets with respect to virus subtype (H1N1 or H3N2), attenuation method (cold-adapted or avian-human gene reassortment), and human age (adults or children). Furthermore, by comparing the above data sets to a limited number of reported data sets for wild-type virus, we quantified the degree of attenuation of wild-type virus with gene reassortment and estimated its infectivity. As a result, dose-response relationships of all reassortants were best described by a beta-Poisson model. Virus subtype and human age were significant factors determining the dose-response relationship, whereas attenuation method affected only the relationship of H1N1 virus infection to adults. The data sets for H3N2 wild-type virus could be pooled with those for its reassortants on the assumption that the gene reassortment attenuates wild-type virus by at least 63 times and most likely 1,070 times. Considering this most likely degree of attenuation, 10% infectious dose of H3N2 wild-type virus for adults was estimated at 18 TCID50 (95% CI = 8.8-35 TCID50). The infectivity of wild-type H1N1 virus remains unknown as the data set pooling was unsuccessful. 相似文献
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In this paper, we compare two estimators, the RLE (restricted Liu estimator) and the RLSE (restricted least squares estimator) of parameters in linear models under Gauss–Markov models. Using generalized inverse of matrices, we found some equivalency conditions for the superiority of the RLE with respect to the MSE criterion. 相似文献
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杉本达夫 《重庆师范大学学报(哲学社会科学版)》2009,(1)
抗战时期,文协发起的活动中,有保障作家生活、作家权益的运动,也有救助贫病作家的运动.运动得到社会广泛的同情和支持,可是文协内部内藏着难以调整的矛盾,以至成果好像不很理想.政府方面开始给<抗战文艺>以稿费援助.可是,保障公民权方面没有什么前进,相反,言论统制越来越强了.1944年下半年,文协又发起了救助贫病作家运动,取得较好效果. 相似文献
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