Holocene climate likely influenced prehistoric hunter-gatherer subsistence and mobility as changing climate patterns affected food resources. Of interest here is whether climate-driven resource variability influenced peoples in the central Rocky Mountains. This study employed the z-score model to predict how foragers coped with resource variability. The exercise enabled exploration of the relationship between climate, resources, and foraging strategies at High Rise Village (48FR5891), an alpine residential site in Wyoming's Wind River Range occupied between 2800-250 cal B.P. The test was applied to occupations dating to the Medieval Warm Period (1150-550 cal B.P.) and the Little Ice Age (550-100 cal B.P.). Using regional characterizations of temporal variability for these climate periods, a z-score model was employed to develop predictions of how foragers coped with resource variability and predictability during both periods. The model predicted foraging decisions at High Rise Village that managed the risk of caloric shortfall during the slow-changing Medieval Warm Period and the highly variable Little Ice Age. Predictions for each period were tested against corresponding archaeological expectations for subsistence remains, mobility and technology requirements, and the frequency of site use. Further, this study employed a dendroclimatological study to locally characterize the climate periods and test model assumptions of their contrasting patterns of variability. The dendroclimatological study corroborates model assumptions and finds that the Medieval Warm Period was a period of multidecadal climatic variability and resource predictability while the Little Ice Age was characterized by short-term variability and resource unpredictability. Poor preservation of subsistence remains hampered the archaeological study. However, as expected, lithic and chronometric data indicate the site was used residentially and relatively frequently during the Medieval Warm Period, and that use decreased during the Little Ice Age. Medieval use of the site appears to be by Uinta Phase (1800-900 cal B.P.) foragers from the adjacent lowlands, and likely related to regional population pressure, as well as resource accessibility and predictability at High Rise Village. A dramatic decrease in site use predates the Little Ice Age and is likely related to regional population decrease and not LIA conditions at High Rise Village.

Background: Among patients with multiple chronic conditions, care coordination and integration remains one of the major challenges facing the U.S. health care system. A home-based, patient-centered primary care program has been offered through the Veterans Health Administration (VHA) since the 1970s for frail veterans who have difficulty accessing VHA clinics. The VHA Home Based Primary Care (VHA HBPC) aims to integrate primary care, rehabilitation, disease management, palliative care, and coordination of care for frail individuals with complex, chronic diseases within their homes. Early research suggested that VHA HBPC was associated with positive outcomes (e.g., reduced resource use and patient satisfaction). However, evidence regarding the effect of the VHA HBPC program on health services use (especially hospital and nursing home use), expenditures, and other patient outcomes remains limited. The present study is designed to fill this gap as the rise in the number of veterans with complex health care needs will likely increase in the coming decades. Objectives: The current study aimed to examine the impact of VHA HBPC on health services use, expenditures, and mortality among a cohort of new VHA HBPC enrollees identified in the national VHA data system. The specific aims of this study were: 1) to examine the effect of VHA HBPC on major health service use (hospital, nursing home, and outpatient care) paid for by the Veterans Administration; 2) to examine the effect of VHA HBPC on total health services expenditures; and 3) to examine whether VHA HBPC enrollees experienced similar mortality and survival as compared to a matched concurrent cohort. Methods: This study used a retrospective cohort design. A new VHA HBPC enrollee cohort (the treatment group) and a propensity matched comparison cohort (the comparison group) were identified from VHA claims in fiscal years (FY) 2009 and 2010 and were followed through FY 2012. Data on health service use, expenditures, and mortality/survival data were obtained via the VHA administrative datasets (i.e., Decision Support System, Purchased Care, and Vital Status Files). Propensity scores of being enrolled in the VHA HBPC were generated by a logistic regression model controlling for potential confounders. After 41,244 matched pairs were determined adequate through several diagnostic methods, means tests, relative risk analyses, and generalized linear models were used to estimate the effect of VHA HBPC on outcomes. Additionally, a Cox proportional hazards regression model was used to estimate the effect of VHA HBPC on survival. Subgroup analyses were conducted stratifying by age (85 and older), comorbidities (2 or more), and the receipt of palliative care. Based on the results of the original analyses, a series of sensitivity analyses were conducted that modified the described sample selection criteria and matching algorithm. Results: Analyses of the original cohort revealed that VHA HBPC patients had significantly higher risks of being admitted into a hospital (RR 1.53, 95% CI 1.51-1.56) or nursing home (RR 1.65, CI 1.50 - 1.81). The average total expenditures during the study period were significantly higher for the VHA HBPC group as compared to the control group ($85,808 vs. $44,833, respectively; p < .001). In terms of mortality and survival, VHA HBPC enrollees had higher mortality (RR 1.45, CI 1.43 - 1.47), and shorter survival (HR 1.89, CI 1.86 - 1.93) as compared to those in the comparison group. Subgroup analyses found that these relationships generally remained when stratified by age 85 or older or having two or more comorbidities. However, for those who received palliative care, VHA HBPC participants had significantly lower risk of VHA hospitalization overall (RR 0.84, CI 0.81 - 0.87) and immediately prior to death. Finally, exploratory post-hoc analysis suggested that VHA HBPC recipients were at higher risk of VHA hospitalization at 30 (RR 1.11, CI 1.06 - 1.16), 60 (RR 1.16, CI 1.11 - 1.20), and 90 days (RR 1.16, 1.12 - 1.21) prior to death relative to the comparison group. After selecting only those that had a baseline hospitalization and refining the matching algorithm to account for time to death and additional comorbidities, VHA HBPC participants who had been enrolled in the program for at least six months had lower risks for hospital (RR 0.89, CI 0.88 - 0.90) and nursing home admissions (RR 0.74, CI 0.67 - 0.81). However, total expenditures remained significantly higher among those in VHA HBPC relative to the comparison group ($89,761 vs. $85,371, respectively; p < .001). Discussion: This study found that without accounting for important covariates such as initial hospitalization, time to death, and a range of comorbidities, VHA HBPC was associated with higher health service use, higher expenditures, higher mortality, and shorter survival as compared to a similar group of patients not receiving VHA HBPC. After accounting for these factors, VHA HBPC was associated with a lower risk of nursing home use, and after six months, VHA HBPC was associated with lower risk of both nursing home and hospital use. These findings suggest that while VHA HBPC may improve quality of life and patient satisfaction through patient-centered integrated primary care, it may not generate cost savings for the healthcare system. Future research is needed to understand variation in program implementation and how this affects the impact of VHA HBPC on service use and cost.

The use of transformation can usually simplify the analysis of data, especially when the original observations deviate from the underlying assumption of linear model. Box-Cox transformation receives much more attention than others. In this dissertation,. we will review the theory about the estimation, hypotheses test on transformation parameter and about the sensitivity of the linear model parameters in Box-Cox transformation. Monte Carlo simulation is used to study the performance of the transformations. We also display whether Box-Cox transformation make the transformed observations satisfy the assumption of linear model actually.

La phase de primo-infection à VIH qui correspond aux premières semaines de l'infection est une phase cruciale qui détermine en partie l'évolution clinique de la maladie. La dynamique du virus et des lymphocytes T CD4+ (principale cible) durant cette phase est complexe. D'une part cette phase est asymptomatique dans plus de la moitié des cas et est semblable à un syndrome grippal; elle passe par conséquent très souvent inaperçue et peu de données sont disponibles. D'autre part la date d'infection est généralement inconnue ce qui complique l'étude de l'évolution au cours du temps des marqueurs viro-immunologiques. Les modèles dynamiques basés sur des systèmes d'équations différentielles permettent de prendre en compte l'interaction complexe et non-linéaire existant entre le VIH et le système immunitaire. De plus, leur aspect mécanistique peut être très utile pour la compréhension de la physiopathologie ou l'effet d'intervention. Cependant l'estimation de ces modèles est complexe et plusieurs méthodes sont disponibles à ce jour. Nous proposons dans cette thèse une méthode d'estimation pour des modèles dynamiques prenant en compte l'incertitude sur la date d'infection. Nous appliquons cette méthode à un jeu de données réelles de 761 séroconverteurs de la Collaboration CASCADE durant leur première année de suivi. Ces modèles possèdent un grand nombre de paramètres pouvant inclure des effets aléatoires et des variables explicatives. La sélection du meilleur modèle peut nécessiter l'estimation d'un grand nombre de modèles et peut s'avérer très longue. Nous proposons des tests du score pour sélectionner les effets aléatoires et les variables explicatives plus rapidement dans le cadre général des modèles non-linéaires à effets mixtes avec une illustration sur des modèles dynamiques. Enfin, nous proposons de comparer plusieurs modèles biologiques possibles de la primo-infection à VIH pour prédire la dynamique de la charge virale plasmatique et des CD4.

L'inversion de courts segments (moins de 1000 bases) est soupçonnée être un mécanisme majeur de l'évolution des génomes. Deux méthodes de détection ab initio de tels segments sont présentées. La séquence est modélisée par une chaîne de Markov $X^+$. La séquence inverse-complémentaire est alors également modélisée par une chaîne de Markov note $X^-$. Le premier chapitre présente de façon didactique les modèles de Markov utilisés en analyse de séquences génomiques. Une généralisation au cas d'un ordre supérieur à 1 d'un résultat sur la vitesse de convergence vers la distribution stationnaire est également établie. Le deuxième chapitre est consacré à l'étude du score local : $H_(n)=\max_(1\leq i \leq j \leq n)(Y_i+...+Y_j)$, pour une séquence $(Y_1,...,Y_n) \in \R^n$. La loi jointe asymptotique des $r$ plus grandes valeurs de score local est établie à l'aide de la théorie des valeurs extrêmes. Enfin, une démarche de test multiple permettant de choisir $r$ est proposée. Le troisième chapitre propose une statistique de détection fondée sur un rapport de vraisemblance (modèle $X^+$ contre modèle $X^-$) lorsque la longueur du segment retourné est connue. Une approche de type ``fenêtre glissante'' est ensuite appliquée. Une approximation connue de la loi du maximum de ce type de statistique est utilisée pour associer un degré de signification aux segments détectés. Dans le quatrième chapitre, le cas de recherche de segments de longueurs inconnues est traité à l'aide d'une méthode de type score local. Le cinquième chapitre présente l'application de ces méthodes à quelques génomes viraux. Un logiciel développé pour traiter cette problématique est également présenté.

La pneumonie nosocomiale est l'infection la plus fréquente et la plus grave rencontrée en réanimation, notamment chez les patients sous ventilation mécanique invasive. L'objectif de ces travaux de thèse est d'élaborer des outils d'optimisation de la prévention des Pneumonies nosocomiales Acquises sous Ventilation Mécanique (PAVM) en utilisant les informations de la base de donnée OUCOMEREA. Ainsi, un score de PAVM a été construit à partir d'une régression logistique hiérarchique mixte à effet aléatoire permettant de comparer les structures de soin. Le modèle de régression logistique présentant quelques insuffisances, nos travaux ont été orientés vers les modèles multi-états. En particulier, nous avons étudié le modèle Progressive Disability à partir duquel la mortalité attribuable à la PAVM a été évaluée efficacement et les groupes de patients ayant une mortalité imputable très élevée ont été identifié. Ce modèle a été simplifié en modèle Disability. Par la suite, les covariables sont incluses via l'estimateur de Breslow et la mortalité imputable est ré-estimée. A partir du modèle Disability, une prédiction globale et individualisée de la PAVM dans les trois jours qui suivent l'instant d'observation est construite. La performance de la prédiction est évaluée par une fonction de perte pondérée par la fréquence des évènements au cours du temps.

<p>This thesis consists of three papers that examine college choice and earnings among university graduates in Sweden.</p><p>Paper [I] analyzes how geographical accessibility to higher education affects university enrollment decisions in Sweden. The empirical findings show that the probability of enrollment in university education increases with accessibility to university education. The results also indicate that accessibility adds to the likelihood of attending a university within the region of residence. Both these findings are robust with regard to different specifications of accessibility. The empirical results furthermore indicate that the enrollment decisions of individuals with a less privileged background are more sensitive to accessibility to university education than are the decisions of individuals from a more favorable background.</p><p>Paper [II] examines the effect on earnings of graduating from five different college groups. The paper relies on selection on observables and linear regression to identify the earnings effect of college choice. Contrary to the majority of previous Swedish studies, we do not find any systematic differences in estimated earnings between college graduates from the different college groups. This finding does not only hold when considering all college graduates, but also when focusing on men and women separately as well as when considering college graduates in two specific fields of education. The results suggest that an estimator of the earnings effects of college choice that does not properly adjust for ability is likely to be substantially biased.</p><p>Paper [III] estimates the causal effect on earnings of graduating from old universities rather than new universities/university colleges. The study compares estimates from several different matching methods and linear regression. We cannot find any significant differences in earnings between graduates from the two groups of colleges. This holds for male and female sub-samples covering all majors, as well as male and female sub-samples covering two broad fields of education. The results are robust with regard to different methods of propensity score matching and regression adjustment. Furthermore, the results indicate little sensitivity with regard to the empirical support in the data and alternative specifications of the propensity scores.</p>

<p>In this paper I study how the repeal of the Swedish wealth tax (1 of January 2007) has affected people´s labour supply behaviour. This particular issue is relevant because it may help us understand some of the effects of the earnings tax changes that have taken place in Sweden. Accoring to standard economic theory a repealed wealth tax is similar to an income effect for the persons who previously paid the tax. That means that they theoretically will want to consume more leisure, that is decrease their labour supply. The method I am using to test this hypothesis is a difference-in-difference approach where the treatment group consists of persons who previously paid the tax and the control group of comparable persons who did not pay the tax. The data I am using is taken from a Swedish database called LINDA, compiled by the Swedish Central Agency for Statistics (SCB). My main result in this paper is that the repealed wealth tax does not seem to have had any influnece on the labour supply behavior of the persons who previously paid the tax.</p>

<p>Using data from the Labour Force Survey conducted by Statistics South Africa twice yearly this thesis intend to evaluate the Expanded Public Works Programme regarding its effectiveness in creating employment and raising income in households with participating individuals. The South African labour market is well known for its high rates of unemployment and also its segregation, primarily between black and white people, but also young people are having a hard time finding jobs. In order to fight these problems the South African government has launched the Expanded Public Works Programme(EPWP) which provides low- semi-skilled labour with short term employment, the primary target groups being black and coloured people, women, disabled people and young people. Our findings indicate that the EPWP does not significantly enhance the individual’s probability of being employed, nor does it raise the per capita income of households with participating individuals.</p>

The primary purpose of this study is to provide a transcription for solo organ of Virgil Thomson's Symphony on a Hymn Tune. The study is two-fold: first, to explore the early life and career of Thomson with a focused view on how his organ and composition studies influenced the composition of Symphony on a Hymn Tune; and second, to present an original transcription of the work in a performing score for solo organ. In addition to the final score, the study provides an analytical overview along with a description of methodology used to create the transcription, and a discussion of issues encountered by the performing organist in playing the transcription. Discussions encompass organ registration, tempi, manual suggestions, articulation, phrase markings, and dynamic expression. Musical examples both from the author's transcription and Virgil Thomson's organ works are included as necessary. Two appendices are included. Appendix 1 presents the specifications for the Aeolian Skinner organ of The Southern Baptist Theological Seminary in Louisville, Kentucky, on which the transcription was originally performed. Appendix 2 itemizes the registration lists used for the original performance of the organ transcription.