A study of the incubation period, or age at onset, of the transmissible spongiform encephalopathies/prion diseasesWooldridge, Marion Joan Anstee January 1995 (has links)
In order to model epidemics of infectious diseases, particularly to estimate probable numbers of cases with onset at any particular time, it is necessaiy to incorporate a term for the incubation period frequency distribution. Sartwell's hypothesis states that the incubation period frequency distribution for infectious disease is generally a log-normal distribution, based on his examination of disease with short incubation periods. However, it may not apply to diseases with long incubation periods. During the course of an epidemic of a disease with a long incubation period, left and right censoring makes direct observation of the frequency distribution highly unreliable; in addition, time of infection is often unknown. Therefore, for a previously undescribed disease, methods other than direct observation must be employed. One method is to extrapolate from information available for other diseases. In evaluation of Sartwell's hypothesis as applied to diseases with long incubation periods, examination of transfijsion-associated AIDS data was inconclusive. Examination of data for experimental transmissible spongiform encephalopathy (TSE)/prion disease in several species suggests that it may not apply. For natural TSE/prion disease, age at onset is used generally as a 'proxy' for incubation period since infection time is rarely known; the validity of this may vary with the disease type and species being examined. Using this measure, again Sartwell's hypothesis was not confirmed. For both incubation period and age at onset, evidence presented suggests that observed frequency distribution coefficient of skewness is associated with modal age at onset (and thus indirectly with prior age at infection, where appropriate), an earlier modal age at onset resulting in a larger observed coefficient of skewness. The relationship of this association with Sartwell's findings is discussed; they are not incompatible. In addition, an association between observed coefficient of skewness and sample size is demonstrated and the implications discussed.
Modeling and analyzing spread of epidemic diseases: case study based on cervical cancerParvin, Hoda 15 May 2009 (has links)
In this thesis, health care policy issues for prevention and cure of cervical cancer have been considered. The cancer is typically caused by Human Papilloma Virus (HPV) for which individuals can be tested and also given vaccinations. Policymakers are faced with the decision of how many cancer treatments to subsidize, how many vaccinations to give and how many tests to be performed in each period of a given time horizon. To aid this decision-making exercise, a stochastic dynamic optimal control problem with feedback was formulated, which can be modeled as a Markov decision process (MDP). Solving the MDP is, however, computationally intractable because of the large state space as the embedded stochastic network cannot be decomposed. Hence, an algorithm was proposed that initially ignores the feedback and later incorporates it heuristically. As part of the algorithm, alternate methodologies, based on deterministic analysis, were developed, Markov chains and simulations to approximately evaluate the objective function. Upon implementing the algorithm using a meta-heuristic for a case study of the population in the United States, several measures were calculated to observe the behavior of the system through the course of time, based on the different proposed policies. The policies compared were static, dynamic without feedback and dynamic with feedback. It was found that the dynamic policy without feedback performs almost as well as the dynamic policy with feedback, both of them outperforming the static policy. All these policies are applicable and fast for easy what-if analysis for the policymakers.
Antiseptic religion : missionary medicine in 1885-1910 KoreaKim, Shin Kwon January 2017 (has links)
The thesis explores the intersection between medicine and religion in the context of colonisation in Korea in the late nineteenth and early twentieth century. I will focus on the work of medical missionaries from Europe and North America that pursued perfect cleanliness in body, mind and society, including total abstinence and spiritual cleanliness, by spreading biomedical concept of hygiene. One of the points that I will articulate is the ways in which medicine as a colonising force in its own right worked in the mission field to produce 'the docile bodies of people' in the Foucauldian sense. I will argue that what mission medicine in Korea utilised and relied on for its work was a new concept of cleanliness based on biomedical knowledge, the germ theory, rather than the power of colonisation. It was because mission medicine in Korea often worked without collaborating with direct colonial powers. In this sense, Protestant Christianity and biomedicine shared a common foundation in 'cleanliness.' Consequently, I will try to emphasise the multi-dimensional and multi-directional role of the use of cleanliness as an efficacious tool for control of the body. In relation to the historiography of medicine in Korea, I will argue that Confucianism served the social and cultural control of bodies as a medicalised form and that Christianity tried to replace it by providing new knowledge concerning body, disease, health, and cleanliness. In the same respect, I will explore the historical relationship between the germ theory and missionary medicine in Korea. The germ theories of disease were not simply a new etiology but also an effective cultural implement to change people's lives. Thus, the theories did not simply remain in the realm of medicine but were introduced, disseminated, and applied to all matters relating to the body, including its mental and spiritual aspects, through the concept of cleanliness.
Design and implementation of the Disease Control System DiConGoll, Sebastian 26 August 2010 (has links)
This work describes the design and implementation of the Disease Control System DiCon (pronounced [ˈdaɪkɒn]), providing a general framework for solving optimization problems on distributed computer systems. The central aspects of DiCon are discussed, as are decisions made while realizing the system. Several implementation-specific details are highlighted. Real-world applications show the system's flexibility and demonstrate the potential impact DiCon has on public-health decision making. / text
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