Thesis (M.A.) -- Central Connecticut State University, 2009. / Thesis advisor: Glenn Sunshine. "... in partial fulfillment of the requirements for the degree of Master of Arts in History." Includes bibliographical references (leaves [96 - 101]). Also available via the World Wide Web.

The spread of infectious agents has been observed as long as their hosts have existed. The spread of infectious diseases in human populations, however, is more than an academic concern, causing millions of deaths every year, and prompting collective surveillance and intervention efforts worldwide. These surveillance data, used in conjunction with statistical methods and mathematical models, present both challenges and opportunities for advancements in scientific understanding and public health. Early mathematical modeling of infectious diseases in humans began by assuming homogeneous contact among individuals, but has since been extended to account for many sources of non-homogeneity in human contact. Detecting the degree of epidemic mixing between geographically separated populations, in particular, remains a difficult problem. The difficulty occurs because although disease case reports have been collected by many governments for decades, case reporting is imperfect, and transmission events themselves are nearly impossible to observe. The degree to which epidemic coupling can be detected from case reports is the central theme of this thesis. We present a careful, biologically motivated and consistent derivation of the transmission coupling (fully derived in Chapter 4). In Chapter 2 we consider the simple scenario of an epidemic spreading from one population to another, and present both numerical and analytic methodology for estimating epidemic coupling. Chapter 3 considers the problem of estimating epidemic coupling among populations undergoing recurrent epidemics, such as those of childhood diseases which have been widely observed. In Chapter 4 we present a method for estimating coupling among an arbitrary number of populations undergoing an epidemic, and apply it to estimate coupling among the parishes of London, England, during the Great Plague of 1665. / Thesis / Doctor of Philosophy (PhD)

Parmi les approches employées pour caractériser l’état sanitaire des populations antérieures, l’utilisation de l’asymétrie fluctuante (AF) pour rendre compte de la stabilité de développement (DS) du squelette est rare. Après plus d’un demi-siècle de recherches, la DS reste assez méconnue chez l’Homme. Aujourd’hui, les techniques de morphométrie géométrique permettent de quantifier plus finement les variations en analysant de nouveaux aspects morphologiques en 3D.Les objectifs de ce travail étaient:1-Déterminer si l’analyse morpho-géométrique de l’AF chez l’Homme permet de distinguer deux populations.2-Établir si cette distinction peut être attribuée à une différence d’état sanitaire.Les données de deux populations caractérisées par des contextes sanitaires distincts ont été confrontées. Deux échantillons de 70 paires de fémurs adultes d'âge et de sexe comparables ont été sélectionnés. Vingt-sept points-repères ont été positionnés sur chaque surface osseuse reconstruite en 3D. L’AF a été analysée en termes d’amplitude et de localisation sur le fémur.Finalement, cette analyse morpho-géométrique a permis de distinguer deux populations au contextes sanitaires distincts. La population la moins favorisée a exprimé un degré d’AF plus élevé. Considérant l’impact des facteurs potentiels de variation, le stress sanitaire explique le mieux les perturbations de la DS. Au vu de la localisation de l’AF sur le fémur, le facteur biomécanique semble aussi jouer un rôle relatif. Chez l’Homme, la localisation de l’asymétrie fluctuante peut donc être dirigée en partie par les contraintes biomécaniques, cependant son amplitude est principalement influencée par le stress sanitaire. / Among the approaches used to characterize the health status in past populations, the use of fluctuating asymmetry (FA) to evaluate developmental stability (DS) in bone is rare. After more than half a century of research, DS remains relatively unknown in humans. Today, geometric morphometrics techniques offer new perspectives. It is now possible to quantify variations more precisely and approach them by analyzing a new morphological element: shape.The aim of this work was twofold:1-Determine whether the geometric morphometrics analysis of FA in humans can distinguish two populations.2-Determine whether this distinction can be attributed to a difference in health status.The data of two populations of known and distinct health statuses and environmental contexts were compared. Two samples of 70 pairs of adult femurs of comparable age and sex were selected. Two sets of 27 landmarks were placed on the 3D isosurfaces of each femur. FA was analyzed and characterized in terms of range of magnitude and pattern of expression in the femur.Finally, this geometric morphometrics analysis allowed to distinguish two populations that have developed under distinct environmental conditions. The population that experienced higher levels of stress expressed a higher degree of FA. After considering the impact of potential factors of variation, the health stress seems to best explain disturbances of DS. However, given its pattern of expression on the femur, the biomechanical factor seems to play also a relative role. Therefore, in humans, the pattern of expression of FA is directed in part by biomechanical constraints but its magnitude remains mostly influenced by health stress.