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El apiñamiento es un problema frecuente en dentición mixta debido al recambio dentario, falta de espacio, hábitos parafuncionales, entre otros. El objetivo del presente estudio fue comparar los conocimientos y prácticas entre ortodoncistas, odontopediatras y cirujanos dentistas sobre el tratamiento del apiñamiento dentario en dentición mixta. Se encuestó a 416 profesionales divididos en 207 cirujanos dentistas, 77 odontopediatras y 132 ortodoncistas. Se realizó una encuesta virtual de 21 preguntas, con un instrumento con características adecuadas de validez y confiabilidad. Se utilizó la prueba Chi Cuadrado con un nivel de confianza del 95%. En cuanto al nivel de conocimientos, existieron diferencias significativas entre ortodoncistas, odontopediatras y cirujanos dentistas (p=0.002). En la opinión de los tres grupos de profesionales sobre sus prácticas, no hubo diferencias en lo que respecta al mejor momento para iniciar tratamiento (p=0.108), técnica utilizada para realizar stripping dental (p=0.087), aspecto tomado en cuenta para iniciar tratamiento (p=0.889), tratamiento utilizado con mayor frecuencia frente al apiñamiento (p=0.712) y el tipo de aparatología considerada la más efectiva en apiñamiento (p=0.151). Se observó significativamente un mayor nivel conocimientos sobre el tratamiento de apiñamiento dental en odontopediatras, comparado con ortodoncistas y cirujanos dentistas. Se reportaron prácticas similares entre los tres grupos de profesionales con respecto al tratamiento del apiñamiento en dentición mixta. / Crowding is a common problem in mixed dentition due to tooth replacement, lack of space, parafunctional habits, among others. The objective of the present study was to compare the knowledge and practices between orthodontists, pediatric dentists and dental surgeons regarding the treatment of dental crowding in mixed dentition. 416 professionals were surveyed, divided into 207 dental surgeons, 77 pediatric dentists and 132 orthodontists. A virtual survey of 21 questions was carried out, with an instrument with adequate validity and reliability characteristics. The Chi Square test was used with a confidence level of 95%. Regarding the level of knowledge, there were significant differences between orthodontists, pediatric dentists and dental surgeons (p=0.002). In the opinion of the three groups of professionals about their practices, there were no differences regarding the best time to start treatment (p=0.108), technique used to perform dental stripping (p=0.087), aspect taken into account to start treatment (p=0.889), treatment used most frequently against crowding (p=0.712) and the type of appliance considered the most effective in crowding (p=0.151). A significantly higher level of knowledge about the treatment of dental crowding was observed in pediatric dentists, compared to orthodontists and dental surgeons. Similar practices were reported among the three groups of professionals regarding the treatment of crowding in mixed dentition.

This thesis is composed of two essays that study behavioral economics to motivate health-promoting behaviors. The first paper, "Does Nutrition Education Reduce Delay Discounting?," studies delay discounting, or delayed gratification, which is an important research topic because it plays a role in producing numerous health outcomes, such as obesity. It is important to understand how the delay discounting process relates to unhealthy diets. People who discount the value of future outcomes prefer immediate rewards (e.g., enjoyment/taste) even though a larger reward from delaying exists (e.g., good health status). In this paper, we aim to provide evidence over whether nutrition education reduces delay discounting. Our analysis, therefore, provides guidance for designing more effective interventions to help increase overall health. The second paper, "Are We Reaching Those Most In Need?: Motivation Profiles and Willingness-to-Participate," explores the potentially negative psychological spillover effects (i.e., "crowding out" effects), which can complicate incentives' effectiveness because it can make targeted behavior (i.e., the aim to improve one's health) less desirable. To understand this "crowding out" effect, our paper examines how different types of motivations (i.e., intrinsic and extrinsic motivations) influence people's willingness-to-participate in a weight control program with and without incentives. This analysis provides further guidance for designing more effective interventions by considering different recruitment strategies to target different individuals, which can minimize the negative spillover of incentives. / Master of Science

為解決經濟發展過程伴隨的污染問題，常可見到政府和私部門一同投入防治工作，Pearce and Palmer (2001) 發現OECD國家隨著經濟成長，政府逐步提高公共防治支出，而且各個國家私部門的防治投入仍然佔有相當比重。Seldon and Song (1994)、Antle and Heidebrink (1995) 和Komen et al. (1997) 等實證文獻曾提出「倒U字型」EKC成立的原因可能來自環境財為奢侈財，使得經濟成長過程中公共防治投入快速增加，污染才會逐步減少。雖然Pearce and Palmer (2001) 實證OECD國家公共防治投入的所得彈性確實大於1，可是Kriström and Riera (1996) 發現許多國家對環境品質改善之願付價值的所得需求彈性值介於0到1之間，環境品質實為正常財而非奢侈財。鑒於相關實證資料的矛盾，本文從政府公共防治決策過程，了解環境品質所得需求彈性與公共防治投入所得彈性大於1的關聯，以連結環境品質所得需求彈性與EKC成立的關聯。本文證明無需奢侈財的偏好條件，而僅需環境品質偏好為正常財，以及防治技術滿足規模報酬遞增或固定，平均所得提高，消費者對環境品質的主觀願付價格高於客觀代價，模型預期政府將不斷提高防治費率，平均所得水準和防治費率同步增加，公共防治投入的所得彈性必定大於1，污染量終會減少並趨向於零。 實證研究指出並非所有種類污染物的污染水準與平均所得關係，一定呈現「倒U字型」關係，而過去理論模型單從消費者對於環境品質偏好條件，或是單從污染物防治技術是否具備規模報酬遞增，仍不能完全解釋不同污染物與所得關係的差異性。本文強調必須將經濟成長帶動所得分配變化對污染的間接效果納入，有助於釐清不同種類污染物與所得關係的差異性。首先，所得分配固定不變而平均所得提高，只要滿足環境品質偏好為正常財，以及防治技術滿足規模報酬遞增或固定，平均所得對污染的直接效果為「倒U字型」。再則平均所得固定不變時，只要消費者對環境品質的偏好為正常財(而非奢侈財)，所得分配改善，經由多數決投票決定均衡費率反而調降，污染隨之增加。考量高所得國家經濟成長帶動所得分配改善 (即顧志耐曲線存在) 的間接效果，不同污染物面對相同的所得分配變化，唯一的差異僅是防治技術的不同。防治技術之規模報酬遞增並不保證平均所得對污染的淨效果為「倒U字型」，而必須該污染物防治技術之規模報酬指數很高，直接效果大到足以抵銷間接效果，淨效果才可能為「倒U字型」。 另外，本文探討為何世界各國普遍有公私部門同時投入防治的現象，以及研究公共防治支出對私人防治投入產生排擠或排入效果的機制。模型發現無論政府和私部門的防治要素是否為互補要素 (complementary inputs) ，政府和私部門的最適防治投資都不為零。假若私部門增加設備無關乎提升公共防治設備之效能，公共防治增加，將對私人投資產生排擠效果。假若私部門增加設備可以提升公共防治設備之效能，公共防治對私部門防治投資可能產生排擠效果或排入效果，端看該國對於環境品質的重視程度。 政府環境政策制定與私部門防治投資決策的互動息息相關，環境政策的成效實有賴私部門是否願意配合投入防治設備。一旦公共支出對私人投資具排入效果，政府傾向事前宣布較高費率，期望刺激私人投入防治，待事後私人已經投入防治設備，政府則有誘因調降費率。反之，假若公共支出對私人投資具排擠效果，則政府傾向事後再調高費率。只要政府落實事前宣布政策，在符合實證支持的技術條件，污染與平均所得的關係為「倒U字型」的環境顧志耐曲線 (Environmental Kuznets Curve, 以下簡稱EKC) ，若缺乏機制督促政府落實事前宣布政策，且消費者理性預期政府背離意向，當動態一致性 (dynamically consistent) 費率低於事前宣布政策的費率，則執行動態一致性費率所對應的EKC將高於政府確實執行事前政策之EKC；若動態一致性費率高於事前宣布的費率，環境政策的動態不一致反而使得EKC降低。

À cause de la nature complexe et non linéaire de leurs opérations, les salles d’urgence (SU) constituent des entités organisationnelles uniques dans le domaine de la santé. Les SU subissent des pressions accrues résultant des dynamiques des sociétés contemporaines et de leurs systèmes de santé, et font face ainsi à des défis uniques comme l’engorgement. Contrairement aux croyances dominantes sur le phénomène, le présent travail de recherche établit que ce problème est en réalité une manifestation de pauvre performance systémique plutôt qu’une faillite opérationnelle. Alors, pour les SU, la performance organisationnelle relève une importance incontestable. En effet, l’étude de la performance organisationnelle est un sujet de recherche qui intéresse de nombreux chercheurs des services de santé. Il s’agit, néanmoins, d’un concept historiquement difficile à définir à cause de son caractère complexe, multidimensionnel et paradoxal. Le modèle EGIPSS, basé sur la théorie de l’action sociale de Parsons, est capable de saisir cette complexité et constitue un cadre conceptuel robuste et exhaustif, pouvant s’adapter à des contextes divers. Ce mémoire adopte le modèle EGIPSS pour présenter un outil global et intégré d’évaluation de la performance organisationnelle de la salle d’urgences de l’Hôpital Général Régional 46 à Guadalajara, au Mexique. Cet instrument est conçu pour prendre en compte spécifiquement les particularités propres des SU, ainsi que les caractéristiques organisationnelles uniques de l'Hôpital Général Régional 46. Enfin, le développement de ce projet de mémoire contribue aux efforts d’amélioration continue de la performance de cet établissement, et enrichit les connaissances sur les urgences en tant qu’unités organisationnelles. / Because of the complex, nonlinear nature of their operations, emergency rooms (ER) represent unique organizational entities in healthcare. ERs suffer from increased pressures as the result of current social and health care system dynamics, and thus face distinctive challenges like the crowding phenomenon. Contrary to the prevailing thought among researchers, the present work establishes that crowding is a manifestation of poor performance rather than one of operational failure. Therefore, organizational performance is of indisputable importance to emergency rooms. Indeed, the study of performance is a current subject among health services researchers. It is, however, a concept that has been historically difficult to define because of its complex, multidimensional and paradoxical nature. The EGIPSS model, based on Parson’s Social Action Theory, is capable of seizing this complexity and constitutes a solid and comprehensive framework, capable of adapting to different contexts. This thesis adopts the EGIPSS model in order to present a global and integral tool for the evaluation of the organizational performance of the emergency room at Regional General Hospital 46 in Guadalajara, Mexico. This instrument is conceived to specifically address the particularities of ERs, as well as the unique organizational characteristics of Regional General Hospital 46 and the Mexican Health System. Thus, the development of this thesis project contributes to the continuous performance improvement efforts of this institution, and adds to the knowledge of emergency rooms as complex organizations.

La drépanocytose, ou anémie falciforme, présente une variabilité interindividuelle considérable, conditionnée par de multiples facteurs, dynamiques et interactifs, depuis le niveau moléculaire jusqu’au niveau du patient. L’hémoglobine drépanocytaire, ou hémoglobine S (HbS, tétramère a2bS 2), est un mutant de l’hémoglobine A (a2b2) : elle possède à sa surface une valine (hydrophobe) substituant un acide glutamique natif (négativement chargé). Cette mutation entraîne l’agrégation de l’HbS désoxygénée en polymères, ainsi que l’altération des propriétés de l’érythrocyte -dont sa rhéologie et ses interactions avec les différentes cellules vasculaires. C’est pourquoi la polymérisation de l’HbS constitue un facteur étiologique clef, sinon le primum movens, de la drépanocytose, et une hypothèse thérapeutique (étayée par l’observation) postule que la réduction des fibres intra-érythrocytaires de HbS pourrait améliorer le statut clinique des patients en abaissant la fréquence et la sévérité des crises vasoocclusives. Dans l’optique de mieux comprendre et de mieux gérer la variabilité individuelle drépanocytaire, il apparaît donc indispensable de disposer, en premier lieu, d’une description réaliste de la polymérisation de l’HbS. L’objectif de ce travail de thèse est la mise en place et la validation d’un modèle mathématique de la polymérisation de l’HbS désoxygénée, en tant que processus cinétiquethermodynamique, sous l’influence de la concentration et de la température –les deux facteurs modulateurs les plus importants. A partir d’un modèle existant, mais linéaire et incomplet (Ferrone et al., 1985), nous avons procédé à son implémentation, à sa correction et à sa mise à jour, ainsi qu’à l’évaluation quantitative de ses performances dynamiques, par intégration complète et simulation numérique (Simulink©). Ceci nous a permis de réaliser un diagnostic et d’effectuer un certain nombre de raffinements, concernant en particulier (i) la voie de nucléation hétérogène (formation de néo-fibres sur les fibres préexistantes), (ii) la non-idéalité de la solution protéique de HbS, induite par le volume exclus des fibres polymères (coefficients d’activité calculé à partir de la « théorie des particules convexes »), ainsi que (iii) la structuration spatiale des polymères en domaines. Le modèle développé dans ce travail servira de base pour une description (i) de l’influence dynamique de l’oxygénation et des hémoglobines non-polymérisantes sur la polymérisation de HbS, puis (ii) des polymères de HbS sur les propriétés membranaires et rhéologiques de l’érythrocyte drépanocytaire. / Sickle cell disease pathology exhibits a strong interindividual variability, which depends upon multiple, dynamic and interacting factors, from the molecular to the patient level. Sickle hemoglobin, hemoglobin S (HbS, a2bS 2 tetramer), is a mutant of HbA (a2b2), with a surface valine (hydrophobic) substituting a native glutamic acid (negatively charged). Such a mutation endows deoxygenated HbS with the propensity to agregate into polymers, altering erythrocyte properties –including its rheology and its interactions with vascular and circulatory cells. Thus HbS polymerization is a key etiological factor of sickle cell disease, if not the primum movens. Indeed, one therapeutical hypothesis (supported by observation) postulates that the reduction of intra-erythrocytic HbS fibers could improve patients clinical status by lowering the frequency and the severity of vasooclusive crisis. In order to better understand and manage sickle cell disease variability, it is essential to have a realistic description of HbS polymerization. This work aims at developing and validating a mathematical model of deoxygenated HbS polymerization, as a kinetic and thermodynamic process under the influence of concentration and temperature –the two most important modulators. Building on an existing, but linearized and uncomplete (Ferrone et al., 1985) model, we have implemented, corrected and updated, and quantitatively evaluated its dynamical performances: this was done by full numerical integration using Simulink©. This allowed us to make several improvements, related in particular to : (i) the heterogeneous nucleation pathway (seeding and formation of new fibers from pre-existing ones), (ii) the non-ideality of the HbS protein solution, caused by polymer fibers excluded volume (activity coefficients were calculated with the CPT, Convex Particle Theory), and (iii) the spatial organization of polymers into domains. The model developped in this work will ground the description of the dynamic influence (i) oxygenation and non-polymerizing hemoglobins, (ii) HbS polymers interactions with membrane and consequences upon rheological properties of sickle cell erythrocyte.

Das Transfer-Einkommens-Derivativ ist einer der wichtigsten ökonomischen Parameter zur Beantwortung der Frage, ob Sozialrenten den unter Armut leidenden Älteren in voller Höhe zu Gute kommen oder ob politisch unerwünschte Verdrängungseffekte auftreten. Eine Verdrängung privater intergenerationeller Transfers durch die Vergabe von Sozialrenten wird dabei als Schwächung familiärer Strukturen angesehen, da erwachsene Kinder ihre vorherigen privaten finanziellen Unterstützungsleistungen an ihre bedürftigen Eltern kürzen oder gar aussetzen. Die staatlichen Leistungen kämen damit nicht vollständig den Bedürftigen zugute, weshalb die Wirksamkeit von Sozialrenten zur Bekämpfung von Altersarmut in Frage gestellt wird. Der aktuelle internationale Forschungsstand bestätigt die Existenz solcher Verdrängungseffekte bei Sozialtransferprogrammen in Entwicklungs- und Schwellenländern. Die der Dissertation zugrundeliegende empirische Erhebung zu Intrahaushaltstransfers in Mehrgenerationenhaushalten in drei Regionen Nordindiens (Himachal Pradesh, Uttar Pradesh und Delhi) hat jedoch gezeigt, dass theoretische Annahmen der Modelle und landestypische Gegebenheiten Indiens, wie etwa korrupte Vergabemuster bei den Sozialrenten, die Aussagekraft des Transfer-Einkommens-Derivativs zur Beurteilung der Effizienz der Sozialrenten stark einschränken. Die Daten zeigen überdies, dass der Nettotransferstrom abwärts verläuft, von den älteren zu den jüngeren Haushaltsmitgliedern. Dies steht im Gegensatz zu der gängigen Annahme, dass in Entwicklungs- und Schwellenländern die Älteren überwiegend Empfänger privater Transfers sind. / The transfer income derivative is one of the most important economic parameters in understanding whether social pensions serve the elderly poor, as the intended beneficiaries, or whether social pensions crowd out private transfers from family members. The crowding out effect of private transfers by public transfers is seen as weakening traditional family ties because adult children reduce or even cease private transfers to the needy elderly. In that case, public transfers may have no net effect on the income of the elderly calling into question the efficacy of public pension schemes in fighting old age poverty. The current state of international research provides evidence for these crowding out effects in developing or industrializing countries. Drawing on empirical research of intra-household transfers in households with elderly co-residence in three selected north Indian regions (Himachal Pradesh, Uttar Pradesh, and Delhi), this dissertation shows that theoretical assumptions of the models as well as country specific circumstances of India, such as corruption in the allocation of social pensions, limit the explanatory power of the transfer income derivative in judging the efficacy of such pensions. Additionally the data shows that private net transfers flow downward, from the elderly to the younger members of the household. This is in stark contrast to the common assumption that in developing and industrializing countries the elderly are mainly recipients of private transfers.

This study investigates issues of changing recreation use and management in the Greenstone and Caples Valleys. Its underlying research themes are the differing characteristics and activities of four distinct user-groups, how such differences could contribute to conflict in recreation use and management, and the implications of such for management. The conceptual framework used to deal with these issues is the Recreation Opportunity Spectrum (ROS), which is based upon the assumption that quality in recreation experiences and management is best achieved through provision of a range of recreation opportunities. This recognises that objective research input into recreation management cannot substitute for the ultimate subjectivity required in decision-making. Management has two roles here. First, to maintain and/or enhance the range of recreation opportunities availible. Second, to provide users with appropriate signals regarding the availibility of opportunities, and the acceptable norms of use and behaviour. Thus user choice of area and activities undertaken within becomes more a consequence of management action. This differs from most recreation management to date, which has tended to be in response to changing conditions (eg'demand-driven'). The absence of an equitable management approach results in selective reduction of opportunities for certain experiences, as evident from research into effects of conflict/crowding perceptions. In contrast, approaches such as the ROS emphasise management for such opportunities. On this basis and from research results, this study found that maintenance of experiences associated with angling and hunting opportunities in the study area, should be the basis for its management. These opportunities were exploited by relatively more experienced participants. For anglers in particular this was reflected by their characteristics of high activity specialisation. Greater experience and specialisation involved more specific resource requirements and norms of appropriate behaviour. Thus opportunities for hunting and angling in the study area were more susceptible to negative impacts from other uses and users. These impacts would be greatest for angling experiences. This would be more a consequence of perceived inappropriate behaviour by less specialised anglers than a consequence of physical crowding. For hunters these impacts would be primarily a result of concern about the increased presence of others on hunting management, rather than their actual presence. Experiences from the tramping and commercial guided walking opportunities availible are also important, but their participants were relatively less experienced and their recreation opportunities less unique in the region. In the context of an equitable regional ROS approach, there is greater flexibility for their provision elsewhere than there is for experiences from hunting and fishing opportunities. For maintenance of a spectrum of opportunities in the regional ROS, these hunting and angling opportunities should be emphasised in management decision-making. Within the study area itself, management for a regional ROS requires that the Greenstone and Caples Valleys be managed differently. It was clear that the Caples was perceived as providing more 'back-country'-type experience opportunities. In the regional ROS context, management should emphasise maintenance of such opportunities there. Along with this should be noted the greater preference for the CapIes by hunters, and for the Greenstone by anglers.

À cause de la nature complexe et non linéaire de leurs opérations, les salles d’urgence (SU) constituent des entités organisationnelles uniques dans le domaine de la santé. Les SU subissent des pressions accrues résultant des dynamiques des sociétés contemporaines et de leurs systèmes de santé, et font face ainsi à des défis uniques comme l’engorgement. Contrairement aux croyances dominantes sur le phénomène, le présent travail de recherche établit que ce problème est en réalité une manifestation de pauvre performance systémique plutôt qu’une faillite opérationnelle. Alors, pour les SU, la performance organisationnelle relève une importance incontestable. En effet, l’étude de la performance organisationnelle est un sujet de recherche qui intéresse de nombreux chercheurs des services de santé. Il s’agit, néanmoins, d’un concept historiquement difficile à définir à cause de son caractère complexe, multidimensionnel et paradoxal. Le modèle EGIPSS, basé sur la théorie de l’action sociale de Parsons, est capable de saisir cette complexité et constitue un cadre conceptuel robuste et exhaustif, pouvant s’adapter à des contextes divers. Ce mémoire adopte le modèle EGIPSS pour présenter un outil global et intégré d’évaluation de la performance organisationnelle de la salle d’urgences de l’Hôpital Général Régional 46 à Guadalajara, au Mexique. Cet instrument est conçu pour prendre en compte spécifiquement les particularités propres des SU, ainsi que les caractéristiques organisationnelles uniques de l'Hôpital Général Régional 46. Enfin, le développement de ce projet de mémoire contribue aux efforts d’amélioration continue de la performance de cet établissement, et enrichit les connaissances sur les urgences en tant qu’unités organisationnelles. / Because of the complex, nonlinear nature of their operations, emergency rooms (ER) represent unique organizational entities in healthcare. ERs suffer from increased pressures as the result of current social and health care system dynamics, and thus face distinctive challenges like the crowding phenomenon. Contrary to the prevailing thought among researchers, the present work establishes that crowding is a manifestation of poor performance rather than one of operational failure. Therefore, organizational performance is of indisputable importance to emergency rooms. Indeed, the study of performance is a current subject among health services researchers. It is, however, a concept that has been historically difficult to define because of its complex, multidimensional and paradoxical nature. The EGIPSS model, based on Parson’s Social Action Theory, is capable of seizing this complexity and constitutes a solid and comprehensive framework, capable of adapting to different contexts. This thesis adopts the EGIPSS model in order to present a global and integral tool for the evaluation of the organizational performance of the emergency room at Regional General Hospital 46 in Guadalajara, Mexico. This instrument is conceived to specifically address the particularities of ERs, as well as the unique organizational characteristics of Regional General Hospital 46 and the Mexican Health System. Thus, the development of this thesis project contributes to the continuous performance improvement efforts of this institution, and adds to the knowledge of emergency rooms as complex organizations.