On the positional and orientational order of water and methanol around indole: a study on the microscopic origin of solubility

Although they are both highly polar liquids, there are a number of compounds, such as many pharmaceuticals, which show vastly different solubilities in methanol compared with water. From theories of the hydrophobic effect, it might be predicted that this enhanced solubility is due to association between drugs and the less polar -CH3 groups on methanol. In this work, detailed analysis on the atomic structural interactions between water, methanol and the small molecule indole – which is a precursor to many drugs and is sparingly soluble in water yet highly soluble in methanol – reveal that indole preferentially interacts with both water and methanol via electrostatic interactions rather than with direction interactions to the –CH3 groups. The presence of methanol hydrogen bonds with p electrons of the benzene ring of indole can explain the increase in solubility of indole in methanol relative to water. In addition, the excess entropy calculations performed here suggest that this solvation is enthalpically rather than entropically driven.Postprint (author's final draft

Latent protein trees

Unbiased, label-free proteomics is becoming a powerful technique for measuring protein expression in almost any biological sample. The output of these measurements after preprocessing is a collection of features and their associated intensities for each sample. Subsets of features within the data are from the same peptide, subsets of peptides are from the same protein, and subsets of proteins are in the same biological pathways, therefore, there is the potential for very complex and informative correlational structure inherent in these data. Recent attempts to utilize this data often focus on the identification of single features that are associated with a particular phenotype that is relevant to the experiment. However, to date, there have been no published approaches that directly model what we know to be multiple different levels of correlation structure. Here we present a hierarchical Bayesian model which is specifically designed to model such correlation structure in unbiased, label-free proteomics. This model utilizes partial identification information from peptide sequencing and database lookup as well as the observed correlation in the data to appropriately compress features into latent proteins and to estimate their correlation structure. We demonstrate the effectiveness of the model using artificial/benchmark data and in the context of a series of proteomics measurements of blood plasma from a collection of volunteers who were infected with two different strains of viral influenza.Comment: Published in at http://dx.doi.org/10.1214/13-AOAS639 the Annals of Applied Statistics (http://www.imstat.org/aoas/) by the Institute of Mathematical Statistics (http://www.imstat.org

Fixed grid finite element analysis for 3D structural problems

Fixed Grid (FG) methodology was first introduced by García and Steven as an engine for numerical estimation of two-dimensional elasticity problems -- The advantages of using FG are simplicity and speed at a permissible level of accuracy -- Two dimensional FG has been proved effective in approximating the strain and stress field with low requirements of time and computational resources -- Moreover, FG has been used as the analytical kernel for different structural optimisation methods as Evolutionary Structural Optimisation, Genetic Algorithms (GA), and Evolutionary Strategies -- FG consists of dividing the bounding box of the topology of an object into a set of equally sized cubic elements -- Elements are assessed to be inside (I), outside (O) or neither inside nor outside (NIO) of the object -- Different material properties assigned to the inside and outside medium transform the problem into a multi-material elasticity problem -- As a result of the subdivision NIO elements have non-continuous properties -- They can be approximated in different ways which range from simple setting of NIO elements as O to complex noncontinuous domain integration -- If homogeneously averaged material properties are used to approximate the NIO element, the element stiffness matrix can be computed as a factor of a standard stiffness matrix thus reducing the computational cost of creating the global stiffness matrix. An additional advantage of FG is found when accomplishing re-analysis, since there is no need to recompute the whole stiffness matrix when the geometry changes -- This article presents CAD to FG conversion and the stiffness matrix computation based on non-continuous elements -- In addition inclusion/exclusion of O elements in the global stiffness matrix is studied -- Preliminary results shown that non-continuous NIO elements improve the accuracy of the results with considerable savings in time -- Numerical examples are presented to illustrate the possibilities of the metho

Ciencia y conciencia: elementos trazadores de la educación médica

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"La deserción: un fenómeno social". Vivencias de los estudiantes del Programa de Enfermería de la Universidad del Tolima

It has been recognized as an academic dropout problem that is present in all levels of schooling, and in all academic programs in both classroom and distance of the world. The statistics thrown in studies conducted by university students in Latin America show that levels drop from 49% to 73%, and those specifically in the nursing program in Colombia demonstrate higher academic levels drop to 45 %. Objective: To identify the meaning of the experience of having deserted and the factors that led to the desertion of students in nursing program at the University of Tolima. Methodology: Research was conducted with a phenomenological approach, during 2009, with the participation of eight men and six women aged between 19 and 22 years of age, who said that his desertion from the nursing program came from two main causes: the motivation for academic medicine and for reasons of economic order. The technique of data collection was the in-depth interview. Results: The description of each experience helped found between students who dropped into the medicine category such as “life project”, “take your time,” medicine “if science” and nursing “living with the disease”. Conclusion: In contrast to the results of other research in the area, for students of nursing from the University of Tolima who moved to the medical program, desertion meant to make your life plan supported by the environment family.La deserción académica se ha reconocido en el ámbito mundial como un problema presente en todos los niveles de formación escolar y en todos los programas académicos, tanto de modalidad presencial como en modalidad a distancia. Las estadísticas arrojadas por los estudios realizados en estudiantes universitarios en Latinoamérica arrojan niveles de deserción que van desde 49 % hasta el 73 %. Específicamente los estudios efectuados en los programas de enfermería en Colombia demuestran niveles de deserción académica superiores al 45 %. Objetivo: Identificar el significado de la experiencia y los factores que llevaron a la deserción en estudiantes del Programa de Enfermería de la Universidad del Tolima. Metodología: Se realizó una investigación con enfoque fenomenológico durante el 2009, que contó con la participación de ocho hombres y seis mujeres con edades entre 19 y 22 años de edad, quienes expresaron que su decisión de desertar del Programa de Enfermería se dio por dos causas principales: motivación por el programa académico de Medicina, y por problemas de orden económico. La técnica de recolección de la información fue la entrevista en profundidad. Resultados: La descripción de cada experiencia permitió encontrar entre los estudiantes que desertaron hacia el Programa de Medicina categorías como "proyecto de vida"; "tómese su tiempo"; medicina "si es ciencia" y enfermería es "viviendo con la enfermedad". Conclusión: En contraste con los resultados de otros trabajo de investigación realizados en el área, para los estudiantes del Programa de Enfermería de la Universidad del Tolima que se trasladaron al Programa de Medicina la deserción significó poder realizar sus proyectos de vida apoyados por el grupo familiar

"La deserción: un fenómeno social". Vivencias de los estudiantes del Programa de Enfermería de la Universidad del Tolima

It has been recognized as an academic dropout problem that is present in all levels of schooling, and in all academic programs in both classroom and distance of the world. The statistics thrown in studies conducted by university students in Latin America show that levels drop from 49% to 73%, and those specifically in the nursing program in Colombia demonstrate higher academic levels drop to 45 %. Objective: To identify the meaning of the experience of having deserted and the factors that led to the desertion of students in nursing program at the University of Tolima. Methodology: Research was conducted with a phenomenological approach, during 2009, with the participation of eight men and six women aged between 19 and 22 years of age, who said that his desertion from the nursing program came from two main causes: the motivation for academic medicine and for reasons of economic order. The technique of data collection was the in-depth interview. Results: The description of each experience helped found between students who dropped into the medicine category such as “life project”, “take your time,” medicine “if science” and nursing “living with the disease”. Conclusion: In contrast to the results of other research in the area, for students of nursing from the University of Tolima who moved to the medical program, desertion meant to make your life plan supported by the environment family.La deserción académica se ha reconocido en el ámbito mundial como un problema presente en todos los niveles de formación escolar y en todos los programas académicos, tanto de modalidad presencial como en modalidad a distancia. Las estadísticas arrojadas por los estudios realizados en estudiantes universitarios en Latinoamérica arrojan niveles de deserción que van desde 49 % hasta el 73 %. Específicamente los estudios efectuados en los programas de enfermería en Colombia demuestran niveles de deserción académica superiores al 45 %. Objetivo: Identificar el significado de la experiencia y los factores que llevaron a la deserción en estudiantes del Programa de Enfermería de la Universidad del Tolima. Metodología: Se realizó una investigación con enfoque fenomenológico durante el 2009, que contó con la participación de ocho hombres y seis mujeres con edades entre 19 y 22 años de edad, quienes expresaron que su decisión de desertar del Programa de Enfermería se dio por dos causas principales: motivación por el programa académico de Medicina, y por problemas de orden económico. La técnica de recolección de la información fue la entrevista en profundidad. Resultados: La descripción de cada experiencia permitió encontrar entre los estudiantes que desertaron hacia el Programa de Medicina categorías como "proyecto de vida"; "tómese su tiempo"; medicina "si es ciencia" y enfermería es "viviendo con la enfermedad". Conclusión: En contraste con los resultados de otros trabajo de investigación realizados en el área, para los estudiantes del Programa de Enfermería de la Universidad del Tolima que se trasladaron al Programa de Medicina la deserción significó poder realizar sus proyectos de vida apoyados por el grupo familiar

Spatiotemporal variations in exposure: Chagas disease in Colombia as a case study

Age-stratified serosurvey data are often used to understand spatiotemporal trends in disease incidence and exposure through estimating the Force-of-Infection (FoI). Typically, median or mean FoI estimates are used as the response variable in predictive models, often overlooking the uncertainty in estimated FoI values when fitting models and evaluating their predictive ability. To assess how this uncertainty impact predictions, we compared three approaches with three levels of uncertainty integration. We propose a performance indicator to assess how predictions reflect initial uncertainty. In Colombia, 76 serosurveys (1980–2014) conducted at municipality level provided age-stratified Chagas disease prevalence data. The yearly FoI was estimated at the serosurvey level using a time-varying catalytic model. Environmental, demographic and entomological predictors were used to fit and predict the FoI at municipality level from 1980 to 2010 across Colombia. A stratified bootstrap method was used to fit the models without temporal autocorrelation at the serosurvey level. The predictive ability of each model was evaluated to select the best-fit models within urban, rural and (Amerindian) indigenous settings. Model averaging, with the 10 best-fit models identified, was used to generate predictions. Our analysis shows a risk of overconfidence in model predictions when median estimates of FoI alone are used to fit and evaluate models, failing to account for uncertainty in FoI estimates. Our proposed methodology fully propagates uncertainty in the estimated FoI onto the generated predictions, providing realistic assessments of both central tendency and current uncertainty surrounding exposure to Chagas disease

Generation Of Entanglement In Quantum Parametric Oscillators Using Phase Control.

The control of quantum entanglement in systems in contact with environment plays an important role in information processing, cryptography and quantum computing. However, interactions with the environment, even when very weak, entail decoherence in the system with consequent loss of entanglement. Here we consider a system of two coupled oscillators in contact with a common heat bath and with a time dependent oscillation frequency. The possibility to control the entanglement of the oscillators by means of an external sinusoidal perturbation applied to the oscillation frequency has been theoretically explored. We demonstrate that the oscillators become entangled exactly in the region where the classical counterpart is unstable, otherwise when the classical system is stable, entanglement is not possible. Therefore, we can control the entanglement swapping from stable to unstable regions by adjusting amplitude and phase of our external controller. We also show that the entanglement rate is approximately proportional to the real part of the Floquet coefficient of the classical counterpart of the oscillators. Our results have the intriguing peculiarity of manipulating quantum information operating on a classical system.51315