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21.
In the development of many diseases there are often associated random variables which continuously reflect the progress of a subject towards the final expression of the disease (failure). At any given time these processes, which we call stochastic covariates, may provide information about the current hazard and the remaining time to failure. Likewise, in situations when the specific times of key prior events are not known, such as the time of onset of an occult tumour or the time of infection with HIV-1, it may be possible to identify a stochastic covariate which reveals, indirectly, when the event of interest occurred. The analysis of carcinogenicity trials which involve occult tumours is usually based on the time of death or sacrifice and an indicator of tumour presence for each animal in the experiment. However, the size of an occult tumour observed at the endpoint represents data concerning tumour development which may convey additional information concerning both the tumour incidence rate and the rate of death to which tumour-bearing animals are subject. We develop a stochastic model for tumour growth and suggest different ways in which the effect of this growth on the hazard of failure might be modelled. Using a combined model for tumour growth and additive competing risks of death, we show that if this tumour size information is used, assumptions concerning tumour lethality, the context of observation or multiple sacrifice times are no longer necessary in order to estimate the tumour incidence rate. Parametric estimation based on the method of maximum likelihood is outlined and is applied to simulated data from the combined model. The results of this limited study confirm that use of the stochastic covariate tumour size results in more precise estimation of the incidence rate for occult tumours.  相似文献   
22.
1. Special attention is particularly important in addressing the mental health needs of HIV-infected women. These needs may involve issues such as concerns about present or future pregnancy; child-rearing, often as single parents; poverty, illicit drug use or addiction; and the potential lack of support services. 2. Diagnosis of HIV infection in women may be overlooked, as the clinical signs that routinely trigger the suspicion of HIV illness in men are often interpreted to reflect depression or psychological factors, such as stress or overwork, rather than raise the suspicion of HIV infection in women. 3. Understanding a woman's illness cognition is an important component of designing strategies that can enhance coping. The picture a woman generates regarding her illness is a composite of her experiences and responses, and determines to a large extent what she will do in response to her illness.  相似文献   
23.
In this part of the series, the notion of average total inspection (ATI) is introduced to ChSP-4A(c1, c2)r plans, minimizing ATI at a given process average, while protection to the consumer is given in terms of average outgoing quality limit and limiting quality level. The procedure is similar to that of Dodge and Roming.  相似文献   
24.
The years between 1910 and 1920 witnessed the first wave of the "Great Migration" of African Americans to the North. This article uses new census data from the Integrated Public Use Microdata Series project to study self‐selection patterns in African American migration during this important decade. The results indicate that, contrary to contemporary accounts, migration rates rose at least as much among the literate as among the illiterate (and perhaps more), and migration increased more for married African Americans than for the unmarried.  相似文献   
25.
In this article, we look at several issues relating to bilingual education in Latvia, as prescribed by the Latvian Ministry of Education and Science. We examine these issues from the perspective of the past and present situation in Belarus, Russia and the former Soviet Union. It is clear, in our view, that bilingual offers both advantages, but also various drawbacks if it is not implemented in an appropriate way. This applies to both the societal and the personal (cognitive level). Movement towards the dominant languages (in this case Latvian) needs to be viewed as a gradual process. Although each generation of newcomers might start with a passive knowledge of the dominant (second) language, this changes into a fluent grasp of the second language across generations. The original native language will lose its dominance in this process.  相似文献   
26.
A general form for characterizing inverse Gaussian and Wald distributions, based on their respective length-biased distributions, is introduced. Further results for characterizations of the gamma distribution, the negative binomial distribution and some mixtures of them by using their lengthbiased distributions are establised.  相似文献   
27.
The authors examine the effect of premarital cohabitation on the division of household labor in 22 countries. First, women do more routine housework than men in all countries. Second, married couples that cohabited before marriage have a more equal division of housework. Third, national cohabitation rates have equalizing effects on couples regardless of their own cohabitation experience. However, the influence of cohabitation rates is only observed in countries with higher levels of overall gender equality. The authors conclude that the trend toward increasing cohabitation may be part of a broader social trend toward a more egalitarian division of housework.  相似文献   
28.
This article illustrates how Uyghurs in the 1990s defined and reinforced contemporary Uyghur national identity in relation to Xinjiang's growing Han Chinese population. Adopting Barth's theory of fluid and negotiable ethnic boundaries, it focuses on the notion of change. While Uyghurs are currently activating and exaggerating certain religio-cultural differences--in particular the avoidance of pork--as a means of ensuring symbolic, spatial and social segregation from the Han, those criteria did not prevent interaction to the same extent in the past; nor do they prevent Uyghurs from making concessions when it benefits them to do so. It is argued that it is not religio-cultural differences per se that lie at the root of increased tensions between Uyghurs and Han Chinese, but changing social, political and economic contexts: on the one hand, growing Uyghur perceptions of socio-economic inequalities between themselves and the Han (the 'internal factor') and, on the other, the vast changes within the international political arena since the late 1980s (the 'external factor').  相似文献   
29.
This article explores the effectiveness of self-defense training for college women. Advocates of self-defense training believe these courses will not only provide women with the physical survival techniques necessary to repel attacks effectively, but that this kind of training will also help to prevent future violence by developing traits such as assertiveness and confidence in individuals. There is evidence that women who convey such characteristics are less likely to be victimized. Opponents argue that self-defense training does not properly prepare women for an attack, does not adequately address acquaintance rape threats, and can provide a dangerous false sense of security to students. This article reviews the relevant literature, outlines practical suggestions for initiatives in this area, and describes a model self-defense course at one university. Guidelines for evaluation and implications for university policy and program decisions that address violence against women on college campuses are included.  相似文献   
30.
In this paper, the notion of average total inspection (ATI) is introduced to ChSP-4(c1,c2) sampling plans. Procedures have been developed for the construction and selection of ChSP-4(c1, c2 plans, minimizing ATI at a given process average, while protection to the consumer is given in terms of the (i) average outgoing quality limit and (ii) limiting quality level.A wide range of c1 and c2 values are considered for developing tables which cover almost all practical situations. The procedure described is similar to that of Dodge and Romig.  相似文献   
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