A two-mutation model for carcinogenesis is reviewed. General principles in fitting the model to epidemiologic and experimental data are discussed, and some examples are given. A general solution to the model with time-dependent parameters is developed, and its use is illustrated by application to data from an experiment in which rats exposed to radon developed lung tumors. 相似文献
Michael Polanyi’s defense of freedom in science and society conflicts in major ways with Weber (process of rationalization,
value neutrality of sociologists), Popper (objective knowledge, open society), and technological or oppositional sociology.
Polanyi rejects positivism, utilitarianism, and Marxism, and defends freedom as a necessary condition for pursuit of spiritual
ideals such as truth, justice, charity, and tolerance. Half truths about science seen as rejecting tradition, faith, authority,
values, and the subjective, have helped bring valuable social results, but in the form taken by radical philosophical skepticism
(doubt), also called objectivism, they also threaten freedom itself. A more truthful account is needed. Scientists and citizens
who would maintain a free society are morally responsible persons, joined together in quest of truth and certain other ideals,
demanding of themselves and each other that they be faithful to that quest. Polanyi’s thought has connections with that of
Shils, and has implications for what Shils calls a consensual sociology.
Louis H. Swartz teaches law, and is interested in the development of sociological theory and legal sociology, building upon
the contributions of Polanyi and Shils. 相似文献
Conventional parametric representations of stable law distributions do not allow all members of the family to be obtained as continuous limits of the parameters. Model building (or simulation) using such representations will be numerically unstable near such limits in consequence. Existing tables are not satisfactory near such limits as interpolation cannot be carried out. We show that these difficulties are overcome by using a new shifted Cartesian representation which characterizes the entire stable law family in a completely continuous way. Standardization is still possible with this representation so that tabulation, using just two bounded parameters, can be carried out. Its use is illustrated in a non-regular threshold estimation problem involving stable distributions which are discontinuous limits in conventional representations. 相似文献
Using direct measures of district opinion, this article teststhe linearity and additivity assumptions of the surrogate model.Neither assumption is upheld when subjected to appropriate empiricaltests 相似文献
Campylobacteriosis is an important food-borne illness with more than a million U.S. cases annually. Antibiotic treatment is usually not required. However, erythromycin, a macrolide antibiotic, is recommended for the treatment of severe cases. Therefore, it is considered a critically important antibiotic and given special attention as to the risk that food animal use will lead to resistant infections and compromised human treatment. To assess this risk, we used a retrospective approach; estimating the number of campylobacteriosis cases caused by specific meat consumption utilizing the preventable fraction. We then determined the number of cases with macrolide resistance Campylobacter spp. based on a linear model relating the resistance fraction to on-farm macrolide use. In this article, we considered the uncertainties in the parameter estimates, utilized a more elaborate model of resistance development and separated C. coli and C. jejuni . There are no published data for the probability of compromised treatment outcome due to macrolide resistance. Therefore, our estimates of compromised treatment outcome were based on data for fluoroquinolone-resistant infections. The conservative results show the human health risks are extremely low. For example, the predicted risk of suboptimal human treatment of infection with C. coli from swine is only 1 in 82 million; with a 95% chance it could be as high as 1 in 49 million. Risks from C. jejuni in poultry or beef are even less. Reduced antibiotic use can adversely impact animal health. These low human risks should be weighed against the alternative risks. 相似文献
The effects of day-sleep on the quality ofsleep are not restricted to the night-work period itself. Effects can be measured during night-sleep in the period following night-work. A study on these after-effects, using a self-report instrument to measure sleep quality, is described. A total of N=7O operators wcrc observed over five consecutive undisturbed nights after a working period of seven morning shifts (N= 35) and after a working period of seven night-shifts (N= 35). The quality of sleep during the third night after the night-shift period was still significantly worse than the third night after the rnorning-shift period. No differential (after-)effects were observed with respect to differences in sleep duration. 相似文献
We exploit the fact that the Wilcoxon score R-estimator of the slope in a linear regression model minimises Gini's mean difference of the residuals to obtain a Berry-Esseen rate of convergence result for the Wilcoxon R-estimator. 相似文献
Two individuals who sustained traumatic brain injuries from motorcycle accidents were taught several verbal responses by using tact, mand, and intraverbal training procedures. The rate of acquisition for each operant and the transfer to untrained verbal operants involving the same response topography were measured. The results showed that tacts and intraverbals were acquired quickest, and training on the tact produced the greatest amount of transfer to the untrained verbal operants. Intraverbal training also resulted in transfer for both subjects, but to varying degrees. Direct mand training proved to be the least efficient way to generate a mand repertoire, and when acquired showed least amount of transfer to the untrained operants. These results seem to be in contrast with the findings of similar research with developmentally disabled individuals, and may have implications for methods of language instruction for the brain injured population.