Discrete second order constrained lagrangian systems: first results

We briefly review the notion of second order constrained (continuous) system (SOCS) and then propose a discrete time counterpart of it, which we naturally call discrete second order constrained system (DSOCS). To illustrate and test numerically our model, we construct certain integrators that simulate the evolution of two mechanical systems: a particle moving in the plane with prescribed signed curvature, and the inertia wheel pendulum with a Lyapunov constraint. In addition, we prove a local existence and uniqueness result for trajectories of DSOCSs. As a first comparison of the underlying geometric structures, we study the symplectic behavior of both SOCSs and DSOCSs.Facultad de Ciencias Exacta

Discrete second order constrained lagrangian systems: first results

We briefly review the notion of second order constrained (continuous) system (SOCS) and then propose a discrete time counterpart of it, which we naturally call discrete second order constrained system (DSOCS). To illustrate and test numerically our model, we construct certain integrators that simulate the evolution of two mechanical systems: a particle moving in the plane with prescribed signed curvature, and the inertia wheel pendulum with a Lyapunov constraint. In addition, we prove a local existence and uniqueness result for trajectories of DSOCSs. As a first comparison of the underlying geometric structures, we study the symplectic behavior of both SOCSs and DSOCSs.Facultad de Ciencias Exacta

Establecimientos gastronómicos enfocados a la distribución de pequeñas muestras de la gastronomía colombiana

Ilustraciones, gráficosPlan de negocios para un restaurante especializado en un menú de pequeñas proporciones donde se pretende transmitir un ambiente sensorial por medio de las preparaciones, el diseño del establecimiento, música y juegos tradicionales que se pretende desarrollar en la ciudad de Bogotá; con el fin de resaltar la cultura y la gastronomía de Colombia. Para ello se utilizó el método Canva que llevo al análisis del sector y de los factores que influirían en el proyecto desde el punto de vista financiero, administrativo, innovador y publicitario. Esto permitió analizar la zona de entrada, quinta Camacho (avenida chile con calle 72), en un mercado tan competitivo como el gastronómico, dirigido principalmente a esa categoría millenian en un rango de edad de 18 a 25 años sin Importar su nacionalidad. A su vez permitió generar una idea diferencial propositiva, capaz de generar resultados positivos desde sus primeros años de posible apertura.It's a business plan for a specialized restaurant on small portions menu, which pretends to transmit a sensorial environment by preparations, infrastructure, design, music and traditional games in Bogotá city; with the propose of stand out the Colombian culture and gastronomy. For that reason, we used Canva method, to make an analysis of the sector and the factors that influence the project under the financial, administrative, innovative and advertising point of view. That fact allows to analyze the planned area in a gastronomical perspective: Quinta Camacho (Avenida Chile con Calle 72), focused on millennial generation under an age range of 18 to 25 years old, no matter them nationality. Also, it brings a differential and purposeful idea, able to generate positive results during the first opening years.Administrador de Empresas Turísticas y HotelerasPregrad

Polypharmacy is associated with functional decline in Alzheimer's disease and Lewy body dementia

Antecedentes: en la demencia, varios factores pueden influir en el deterioro funcional además de la cognición. En Este estudio, nuestro objetivo es estudiar la posible asociación del número de medicamentos prescritos con funcional trayectorias de declive durante un seguimiento de cinco años en personas diagnosticadas con enfermedad de Alzheimer leve (EA) o Demencia con cuerpos de Lewy (LBD). Métodos: Este es un análisis longitudinal de un estudio de cohorte noruego titulado "El estudio de la demencia de occidente Noruega". Se incluyeron 196 pacientes con diagnóstico reciente de EA (n = 111) y LBD (n = 85), seguidos anualmente durante 5 años. Realizamos modelos lineales de efectos mixtos para analizar la asociación del número de medicamentos con declive funcional medido por la Escala Rápida de Calificación de Discapacidad - 2. Resultados: La media de medicamentos prescritos al inicio del estudio fue 4,18∓2,60, para AD 3,92∓2,51 y LBD 4,52∓2,70. El número de medicamentos aumentó durante el seguimiento; en el quinto año, la media de EA fue de 7,28∓4,42 y para LBD 8.11∓5.16. El uso de más medicamentos se asoció con un deterioro funcional más rápido en la EA (Est. 0.04, SE0.01, valor p 0.003) y LBD (Est 0.08, SE 0.03, valor p 0.008) después de ajustar por edad, sexo, comorbilidad, síntomas neuropsiquiátricos y cognición. Para cada medicamento agregado durante el seguimiento, funcional las trayectorias empeoraron en un 1% para AD y 2% para LBD. El número de medicamentos no se asoció con factores cognitivos. disminución. Conclusión: Encontramos que un mayor número de medicamentos se relacionó con un deterioro funcional más rápido, tanto en la EA y LBD. La prescripción, especialmente en la demencia, debe evaluarse cuidadosamente, por lo que el pronóstico en la demencia podría posiblemente se mejore.Q1Q1Background: In dementia, a number of factors may influence functional decline in addition to cognition. In this study, we aim to study the potential association of the number of prescribed medications with functional decline trajectories over a five-year follow-up in people diagnosed with mild Alzheimer's disease (AD) or Lewy Body dementia(LBD). Methods: This is a longitudinal analysis of a Norwegian cohort study entitled “The Dementia Study of Western Norway”. We included 196 patients newly diagnosed with AD (n=111) and LBD (n=85), followed annually for 5 years. We conducted linear mixed-effects models to analyze the association of the number of medications with functional decline measured by the Rapid Disability Rating Scale – 2. Results: The mean prescribed medications at baseline was 4.18∓2.60, for AD 3.92∓2.51 and LBD 4.52∓2.70. The number of medications increased during the follow-up; at year five the mean for AD was 7.28∓4.42 and for LBD 8.11∓5.16. Using more medications was associated with faster functional decline in AD (Est 0.04,SE0.01, p-value 0.003) and LBD (Est 0.08, SE 0.03, p-value 0.008) after adjusting for age, sex, comorbidity, neuropsychiatric symptoms, and cognition. For each medication added during the follow-up, functional trajectories worsened by 1% for AD and 2% for LBD. The number of medications was not associated with cognitive decline. Conclusion: We found that higher number of medications was related to a faster functional decline, both in AD and LBD. Prescription especially in dementia should be carefully assessed, thus prognosis in dementia might possibly be improved.https://orcid.org/0000-0001-5832-0603https://scholar.google.com/citations?user=MrICwaMAAAAJ&hl=enhttps://scienti.minciencias.gov.co/cvlac/visualizador/generarCurriculoCv.do?cod_rh=0001429659&lang=esRevista Internacional - Indexad

Tongue muscle mass is associated with total grey matter and hippocampal volumes in Dementia with Lewy Bodies

Background Age-related neurodegeneration, sarcopenia, and ectopic fat accumulation are conditions with shared pathways that remain poorly understood. We have measured muscle volume and fat accumulation in masseter and tongue muscle, and aim to explore their association with the total grey matter volume using MRI in older adults recently diagnosed with Alzheimer's disease (AD) and Dementia with Lewy bodies (DLB). Methods In this cross-sectional study, people newly diagnosed with mild AD (n=33) and DLB (n=20) underwent structural head MRI. Muscle volume and intramuscular fat (iMAT) of the tongue and masseter were computed using Slice-O-Matic software for segmentation. Total grey volume and hippocampal volumetric segmentation were performed with the FreeSurfer image analysis suite version 6.0. Independent regression models were employed to analyse the associations. Results Tongue iMAT was higher and total grey volume lower in DLB compared to AD. In the DLB group, tongue muscle was positively associated with total grey matter volume Est 0.92 (SE 0.24 p-value 0.002), left- Est 0.01 (SE 0.0028 p-value 0,002), and right- Est 0.0088 (SE 0.0027 p-value: 0.005) hippocampal volume. There were no statistically significant results for AD. Conclusion Tongue muscle volume was positively associated with hippocampal and total grey volume in DLB. Longitudinal designs are required to explore the extent and significance of this association.acceptedVersio

Factors associated with nutritional status in hospitalized elderly patients

Introducción: la desnutrición es una condición frecuente en las personas mayores de 65 años. El mal estado nutricional se ha relacionado con mayores estancias hospitalarias, complicaciones, aumento en comorbilidades y mortalidad. Este estudio busca describir la relación entre el estado nutricional de adultos mayores hospitalizados y factores como red de apoyo, funcionalidad y pre-sencia de demencia.Material y métodos: se llevó a cabo un estudio descriptivo de corte transversal analítico basado en la revisión de historias de los pacientes hospitalizados por el Servicio de Geriatría del Hospital Universitario San Ignacio de Bogotá D.C. La variable dependiente fue el estado nutricional medido con el instrumento Mini-Nutritional Assessment y se usaron como variables independientes factores sociodemográficos, el estado funcional, el diagnóstico previo de demencia, la red de apoyo, delirium, tiempo de estancia hospitalaria, comorbilidades.Resultados: se incluyeron 887 pacientes con edad promedio de 85.43 años, de los cuales 43.07% eran hombres. En el modelo de regresión logística la presencia de delirium OR 2.27 (IC 1.48-3.48), el diagnóstico previo de demencia OR 2.48 (IC 1.63-3.77) y el mayor tiempo de estancia hospitalaria OR 1.05 (IC 1.0-1.10 ) tuvieron una asociación de aumento de riesgo con desnutrición.Conclusión:se encontró una asociación significativa entre mal estado nutricional con menor funcionalidad, mayor estancia hospitalaria, tener diagnóstico de demencia, presentar delirium, tener un mayor número de comorbilidad y mayor mortalidad. Se requieren más estudios que aborden este tema.Artículo original69-73Introduction: malnutrition is a prevalent condition in people older than 65 years. Poor nutri-tional status has been associated to longer hospital stays, complications, increased comorbidities and mortality. This study aims to describe the relationship between the nutritional status of hospital-ized older adults and factors such as support network, functionality and the presence of dementia.Materials and methods: a descriptive cross-sectional analytical study was carried out based on the revision of medical records of patients hospitalized by the Geriatrics Unit at San Ignacio University Hospital in Bogota, Colombia. Nutritional status measured through theMini-Nutritional Assessment was considered to be the dependent variable. Sociodemographic factors, functional status, previous diagnosis of dementia, support network, delirium, length of hospital stay and pres-ence of comorbidities were used as independent variables.Results: 887 patients with an average age of 85.43 were included. 43.07% were men. The logistic regression model revealed that the presence of delirium OR 2.27 (CI 1.48-3.48), the diag-nosis of dementia OR 2.48 (CI 1.63-3.77) and the longer hospital stay OR 1.05 (CI 1.0-1.10) had an association of increased risk with malnutrition. Conclusion: a significant association was found between poor nutritional status with decreased functionality, longer hospital stays, having a diagnosis of dementia, presenting delirium, having a greater number of comorbidity and higher mortality. Future studies addressing this issue are required

Relación del edentulismo con la autoevaluación del estado de la salud : un análisis secundario del estudio SABE Ecuador 2009

El edentulismo se ha asociado con una gran variedad de condiciones en los adultos mayores afectando el estado general de su salud. Por lo tanto, afecta la calidad de vida de la persona y su relación con el medio ambiente. Por otro lado, la autoevaluación de la salud ha demostrado ser un marcador preciso del estado general de la salud. Sin embargo, hay escasa información sobre cómo estas dos condiciones se relacionan entre sí en adultos mayores de origen hispano. El objetivo de este estudio fue evaluar el impacto del edentulismo en la autoevaluación de la salud en adultos mayores. Se analizaron los datos de SABE Ecuador 2009, un estudio transversal que incluyó una muestra probabilística y representativa de 5.235 personas de 60 años de edad o más. La variable dependiente fue la salud autoevaluada yedentulismo fue la variable independiente, teniendo edad, sexo y comorbilidades como variables de confusión. Con el fin de probar la asociación independiente de edentulismo con la auto¬evaluación de la salud un modelo de regresión logística se ajustó. De la muestra entera, un 77,13% de los adultos mayores reportaron tener salud auto¬evaluada regular / pobre. Se encontró una asociación independiente entre edentulismo y salud autoevaluada con un riesgo incremental dependiendo del número de dientes ausentes de OR 1,35 (IC 95% 0,75 ¬ 2,43) p 0,32, en adultos mayores con menos de 4 dientes ausentes hasta OR 1,88 (1,06 ¬ 3,32) p 0,029, con más de la mitad de dientes ausentes. La salud oral se ha considerado de forma independiente del resto del cuerpo y la mente, es claro por nuestros resultados que la salud oral es un componente muy importante del estado de salud global en las personas mayores.Q3Artículo original83-89Edentulism is related to a number of conditions in older adults, impacting their overall health status and thus their quality oflife and relationship with the environment. At the same time,self¬rated health has been shown to be an accurate marker ofoverall health status. However there is little information onhow edentulism relates to self¬rated health in older adults ofHispanic origin. The aim of this study was to evaluate the impact of edentulismon self¬rated health in older adults.We analyzed data from SABE Ecuador 2009, a cross¬sectionalstudy that included a probabilistic representative sample of5,235 community¬dwelling older adults aged 60 years or older.The dependent variable was self-rated health and theindependent variable was edentulism, with age, sex andcomorbidities as confounding variables.In order to test the independent association of edentulism with self¬rated health, alogistic regression model was fitted.Out of the whole sample,77.13% of older adults reportedhaving fair/poor self¬rated health. We found an independentassociation between edentulism and self¬rated health withincremental risk according to number of missingteeth,rangingfrom OR 1.35 (CI 95% 0.75 ¬ 2.43) p 0.32 for less than 4missing teeth to OR 1.88(1.06 ¬ 3.32) p 0.029 for more thanhalf of teeth missing.Even though oral health has long been considered separatelyfrom the rest of the body and mind, it is clear from our resultsthat oral health is a very important component of global healthstatus in the elderly

Excitation of local magnetic moments by tunnelling electrons

The advent of milli-kelvin scanning tunneling microscopes (STM) with inbuilt magnetic fields has opened access to the study of magnetic phenomena with atomic resolution at surfaces. In the case of single atoms adsorbed on a surface, the existence of different magnetic energy levels localized on the adsorbate is due to the breaking of the rotational invariance of the adsorbate spin by the interaction with its environment, leading to energy terms in the meV range. These structures were revealed by STM experiments in IBM Almaden in the early 2000's for atomic adsorbates on CuN surfaces. The experiments consisted in the study of the changes in conductance caused by inelastic tunnelling of electrons (IETS, Inelastic Electron Tunnelling Spectroscopy). Manganese and Iron adatoms were shown to have different magnetic anisotropies induced by the substrate. More experiments by other groups followed up, showing that magnetic excitations could be detected in a variety of systems: e.g. complex organic molecules showed that their magnetic anistropy was dependent on the molecular environment, piles of magnetic molecules showed that they interact via intermolecular exchange interaction, spin waves were excited on ferromagnetic surfaces and in Mn chains, and magnetic impurities have been analyzed on semiconductors. These experiments brought up some intriguing questions: the efficiency of magnetic excitations was very high, the excitations could or could not involve spin flip of the exciting electron and singular-like behavior was sometimes found at the excitation thresholds. These facts called for extended theoretical analysis; perturbation theories, sudden-approximation approaches and a strong coupling scheme successfully explained most of the magnetic inelastic processes. In addition, many-body approaches were also used to decipher the interplay between inelasComment: Review article to appear in Progress of Surface Scienc

Antología del pensamiento Social en Colombia

PublishedEl quehacer de la filosofía no es límite de este ejercicio, la recopilación de estos documentos trata de un ejercicio interdisciplinar. La sociología, la historia, la antropología y otras disciplinas se abren campo en esta indagación; quizá esto sea parte del carácter original del pensamiento social: el ejercicio académico dialógico. Así, la conjugación de ciencias, miradas e indagaciones es el carácter prioritario y, sin embargo, cada documento se muestra lejos del que lo precede y del que lo antecede. Por pensamiento social, entonces, entiéndase la episteme que rigurosa y profundamente revisa ideas, pensamientos, teorías y realidades en aras a fortalecer una construcción crítica de la esfera pública. El saber se construye con un fin práctico y con una naturaleza plural, es decir, el fin es la construcción de comprensiones prácticas y críticas en torno a las necesidades de lo social, que tienen en su naturaleza la pluralida