Allostatic Load in Relation to Periodontal Disease, Tooth Loss, and Mortality: Findings from the 1914 Glostrup Aging Study

As the proportion of adults aged 65 years and older continues to grow across the globe and edentulism rates decline, there is widespread concern about a rise in the prevalence of periodontal disease, characterized by chronic inflammation of tooth-supporting tissues induced by persistent infection. Compared to their younger counterparts, older adults experience a higher burden of periodontal disease, which can result in tooth loss, poor nutritional intake, higher prevalence of other chronic diseases, and a decrease in overall quality of life. While cross-sectional studies have underscored the role of chronic stress on periodontal disease progression in older adults, longitudinal evidence is currently lacking. This dissertation draws on prospective data from a birth cohort of older Danish adults (1914 Glostrup Aging Study) with 25 years of follow-up. Using physiological markers than span the metabolic, inflammatory, and cardiovascular systems, I developed a composite measure of allostatic load (AL) at age 80, defined as the cumulative biological damage that results from a whole-body adaptation to chronic stress. First, I identified social and behavioral predictors of high scores on AL. In men, those with no vocational training, unskilled occupation, low income, and a sedentary lifestyle were more likely to have high AL, consistent with a "weathering" pattern of biological systems resulting from chronic adversity over the life course. To test the hypothesis that high AL is longitudinally associated with periodontal disease, I evaluated bidirectional longitudinal associations using multiple measures of AL and periodontal disease. Results showed a positive nonlinear association of AL at age 70 with periodontal disease at age 85, but no association between periodontal disease at age 70 with AL at age 80. This finding confirms previous cross-sectional data, and supports the role of chronic stress on infection-induced inflammation. To test the hypothesis that high AL is associated with mortality risk, I examined this association longitudinally from ages 70 - 95. Compared to low AL, high AL was positively associated with all-cause mortality, and even stronger when cardiovascular disease mortality was considered. AL-mortality associations were higher among those who were dentate as compared to edentate, suggesting that dentate status modifies the relationship. Findings from this dissertation contribute to our understanding of the consequences of stress on periodontal disease in relation to aging and offer potential avenues for intervention

Critical Analysis of the article: "Dogs as Role Models" by Richard Curwin

The article “Dogs as Role Models: A lesson in classroom management” written by Richard Curwin on august, 17th 2012, is a research where the author exposes an experience that he had many years ago with his dog and how he could associate this event with the classroom management and the behavior of his students

Scanning tunneling microscopy on low dimensional systems: dinickel molecular complexes and iron nanostructures

This thesis contains experimental studies on low dimensional systems by means of scanning tunneling microscopy (STM). These studies include investigations on dinickel molecular complexes and experiments on iron nanostructures used for the implementation of the spin-polarized scanning tunneling microscopy technique at the IFW-Dresden. Additionally, this work provides detailed information of the experimental technique (STM), from the theoretical background to the STM-construction, which was part of this doctoral work. Molecular anchoring and electronic properties of macrocyclic magnetic complexes on gold surfaces have been investigated by mainly scanning tunneling microscopy and complemented by X-rays photoelectron spectroscopy. Exchange–coupled macrocyclic complexes [Ni2L(Hmba)]+ were deposited via 4-mercaptobenzoate ligands on the surface of Au(111) single crystals. The results showed the success of gold surface-grafted magnetic macrocyclic complexes forming large monolayers. Based on the experimental data, a growth model containing two ionic granular structures was proposed. Spectroscopy measurements suggest a higher gap on the cationic structures than on the anionic ones. Furthermore, the film stability was probed by the STM tip with long-term measurements. This investigation contributes to a new promising direction in the anchoring of molecular magnets to metallic surfaces. Iron nanostructures of two atomic layers and iron-coated tungsten tips were used in order to implement the spin-polarized scanning tunneling microscopy technique at the IFW-Dresden. First of all, a systematic study of the iron growth, from sub-monolayers to multilayers on a W(110) crystal is presented. Subsequent to the well-understanding of the iron growth, the experiments were focused on revealing, for the first time at the IFW-Dresden, the magnetic inner structure of iron nanostructures. The results evidently showed the presence of magnetic domains of irregular shapes. Furthermore, SP-STM probed the bias voltage dependence of the magnetic contrast on the iron nanostructures. This technique opens up a new powerful research line at the IFW-Dresden which is promising for the study of quantum materials as molecular magnets and strongly correlated systems

Propuesta de inclusión de la metodología Scrum al pensum de Ingeniería de Sistemas y Computación en la Universidad Tecnológica de Pereira

El objetivo de este proyecto de grado es proponer la inclusión al pensum del programa de ingeniería de Sistemas y Computación de la Universidad Tecnológica de Pereira un método ágil de gestión de desarrollo de software como Scrum para con dicha metodología mejorar el trabajo en equipo en esta área en los estudiantes y lograr que al convertirse en egresados puedan obtener un mejor desempeño en el trabajo de desarrollo de software; además poder estar en la línea que viene promocionando MINTIC-Icetex [1] desde el año 2010 para logra hacer de Colombia una potencia mundial en la línea de desarrollo con altos niveles de calidad y eficiencia. Se encontrará las características principales de Scrum y cómo optimiza el desarrollo de un proyecto de software la utilización de esta metodología que es la más difundida y utilizada en el país y el mundo (ver figura 1), para que sea dada la parte teórica en la asignatura que el programa considere mejor y después se aplique de una manera práctica en laboratorio de Software

Hydrological modeling of the Tempisque river basin (Costa Rica) under climate change scenarios

El presente trabajo se desarrolló con el propósito de utilizar el sistema de simulación HydroBID para la modelación hidrológica de la Cuenca del Río Tempisque (Costa Rica), y su comportamiento antes diferentes escenarios de cambio climático. La Cuenca del Río Tempisque está ubicada en la provincia de Guanacaste, Costa Rica, abarcando alrededor de un 10.6% de la superficie continental del país, y juega un papel muy importante en el desarrollo agropecuario del país. Por otra parte, la variabilidad climática en la que está inmerso el país, épocas de sequía y épocas de abundancia en lluvias, hace que sea de interés su análisis y comportamiento futuro, así como la respuesta de la cuenca ante estos factores. La metodología utilizada en este estudio se puede agrupar en 3 etapas, la primera es la recopilación y análisis de información climática de precipitación y temperatura, así como registros de caudal en estaciones a lo largo de la cuenca, la segunda corresponde a la modelación HydroBID y sus herramientas para la caracterización de la cuenca y calibración del modelo, y la tercera etapa corresponde al uso de los modelos calibrados para evaluar la cuenca ante escenarios de cambio climático. Con los resultados obtenidos en el modelo HydroBID y la información base que se pudo recopilar, no se puede generar una caracterización completa de la Cuenca del Río Tempisque, ya que con las estaciones de control disponibles solo se pudo modelar el 24% de la superficie de la cuenca. Se obtuvieron buenas calibraciones para los caudales medios y bajos de la cuenca, no así, para eventos extremos o de altas precipitaciones, obteniendo diferencias de hasta un 67% entre los caudales observados y simulados en los meses de mayor precipitación. Pese a ello, HydroBID se vuelve una herramienta muy versátil para la modelación de las cuencas hidrográficas ante diferentes situaciones, incluyendo escenarios de cambio climático.This work was developed with the main objective of using the HydroBID simulation system for the hydrological modeling of the Tempisque River Basin (Costa Rica), and its behavior under different climate change scenarios. The Tempisque River Basin is located in the province of Guanacaste, Costa Rica, covering around 10.6% of the country's continental surface, and plays a very important role in the country's agricultural development. On the other hand, the climatic variability in which the country is immersed, times of drought and times of abundant rains, make its analysis and future behavior of interest, as well as the response of the basin to these factors. The methodology used in this study can be grouped into 3 stages, the first is the collection and analysis of climate information on precipitation and temperature, as well as flow records at stations throughout the basin, the second focuses on HydroBID modeling, and its tools for the characterization of the basin and calibration of the model, and the third stage corresponds to the use of the calibrated models to evaluate the basin under climate change scenarios. With the results obtained in the HydroBID model and the base information that could be collected, a complete characterization of the Tempisque River Basin cannot be generated, since with the available control stations only 24% of the surface of the basin could be modeled. Good calibrations were obtained for the average and low flows of the basin, but not for extreme events or high rainfall, obtaining differences of up to 67% between the observed and simulated flows in the months with the highest rainfall. Despite this, HydroBID becomes a very versatile tool for modeling river basins in different situations, including climate change scenarios.Máster Universitario en Hidrología y Gestión de Recursos Hídricos (M174