The incidence of necrotizing changes in adults with pneumococcal pneumonia

Background. Necrotizing pneumonia is generally considered a rare complication of pneumococcal pneumonia in adults. We systematically studied the incidence of necrotizing changes in adult patients with pneumococcal pneumonia, and examined the severity of infection, the role of causative serotype and the association with bacteremia. ^ Methods. We used a data base of all pneumococcal infections identified at our medical center between 2000 and 2010. Original readings of chest X-rays (CXR) and computerized tomography (CT) were noted. All images were then reread independently by 2 radiologists. The severity of disease was assessed using the SMART-COP scoring system. ^ Results. There were 351 cases of pneumococcal pneumonia. Necrosis was reported in no original CXR readings and 6 of 136 (4.4%) CTs. With re-reading, 8 of 351 (2.3%) CXR and 15 of 136 (11.0%) CT had necrotizing changes. Overall, these changes were found in 23 of 351 (6.6%, 95% CI 4.0 - 9.1) patients. The incidence of bacteremia and the admitting SMART-COP scores were similar in patients with and without necrosis (P=1.00 and P=0.32, respectively). Type 3 pneumococcus was more commonly isolated from patients with than from patients without necrotizing pneumonia (P=0.05), but a total of 10 serotypes were identified among 16 cases in which the organism was available for typing. ^ Conclusions. Necrotizing changes in the lungs were seen in 6.6% (95% CI 4.0 - 9.1) of a large series of adults with pneumococcal pneumonia. Patients with necrosis were not more likely to have bacteremia or more severe disease. Type 3 pneumococcus was commonly implicated, but 9 other serotypes were also identified.^

Risk factors of pneumonia in traumatic spinal-cord-injured patients

Pneumonia is a well-documented and common respiratory infection in patients with acute traumatic spinal cord injuries, and may recur during the course of acute care. Using data from the North American Clinical Trials Network (NACTN) for Spinal Cord Injury, the incidence, timing, and recurrence of pneumonia were analyzed. The two main objectives were (1) to investigate the time and potential risk factors for the first occurrence of pneumonia using the Cox Proportional Hazards model, and (2) to investigate pneumonia recurrence and its risk factors using a Counting Process model that is a generalization of the Cox Proportional Hazards model. The results from survival analysis suggested that surgery, intubation, American Spinal Injury Association (ASIA) grade, direct admission to a NACTN site and age (older than 65 or not) were significant risks for first event of pneumonia and multiple events of pneumonia. The significance of this research is that it has the potential to identify patients at the time of admission who are at high risk for the incidence and recurrence of pneumonia. Knowledge and the time of occurrence of pneumonias are important factors for the development of prevention strategies and may also provide some insights into the selection of emerging therapies that compromise the immune system. ^

Epidemiology of Acute Lung Injury and Acute Respiratory Distress Syndrome in children in Vietnam

Acute Lung Injury (ALI) and Acute Respiratory Distress Syndrome (ARDS) are life- threatening disorders that can result from many severe conditions and diseases. Since the American European Consensus Conference established the internationally accepted definition of ALI and ARDS, the epidemiology of pediatric ALI/ARDS has been described in some developed countries. In the developing world, however, there are very few data available regarding the burden, etiologies, management, outcome, and factors associated with outcomes of ALI/ARDS in children. ^ Therefore, we conducted this observational, clinical study to estimate the prevalence and case mortality rate of ALI/ARDS among a cohort of patients admitted to the pediatric intensive care unit (PICU) of the National Hospital of Pediatrics in Hanoi, the largest children's hospital in Vietnam. Etiologies and predisposing factors, and management strategies for pediatric ALI/ARDS were described. In addition, we determined the prevalence of HIV infection among children with ALI/ARDS in Vietnam. We also identified the causes of mortality and predictors of mortality and prolonged mechanical ventilation of children with ALI/ARDS. ^ A total of 1,051 patients consecutively admitted to the pediatric intensive care unit from January 2011 to January 2012 were screened daily for development of ALI/ARDS using the American-European Consensus Conference Guidelines. All identified patients with ALI/ARDS were followed until hospital discharge or death in the hospital. Patients' demographic and clinical data were collected. Multivariable logistic regression models were developed to identify independent predictors of mortality and other adverse outcome of ALI/ARDS. ^ Prevalence of ALI and ARDS was 9.6% (95% confidence interval, 7.8% to 11.4%) and 8.8% (95% confidence interval, 7.0% to 10.5%) of total PICU admissions, respectively. Infectious pneumonia and sepsis were the most common causes of ALI/ARDS accounting for 60.4% and 26.7% of cases, respectively. Prevalence of HIV infection among children with ALI/ARDS was 3.0%. The case fatality rate of ALI/ARDS was 63.4% (95% confidence interval, 53.8% to 72.9%). Multiple organ failure and refractory hypoxemia were the main causes of death. Independent predictors of mortality and prolonged mechanical ventilation were male gender, duration of intensive care stay prior to ALI/ARDS diagnosis, level of oxygenation defect measured by PaO2/FiO2 ratio at ALI/ARDS diagnosis, presence of non-pulmonary organ dysfunction at day one and day three after ALI/ARDS diagnosis, and presence of hospital acquired infection. ^ The results of this study demonstrated that ALI/ARDS was a common and severe condition in children in Vietnam. The level of both pulmonary and non-pulmonary organ damage influenced survival of patients with ALI/ARDS. Strategies for preventing ALI/ARDS and for clinical management of the disease are necessary to reduce the associated risks.^

Robust effect sizes and their confidence intervals for group difference between trajectories in hierarchical linear growth model

Hierarchical linear growth model (HLGM), as a flexible and powerful analytic method, has played an increased important role in psychology, public health and medical sciences in recent decades. Mostly, researchers who conduct HLGM are interested in the treatment effect on individual trajectories, which can be indicated by the cross-level interaction effects. However, the statistical hypothesis test for the effect of cross-level interaction in HLGM only show us whether there is a significant group difference in the average rate of change, rate of acceleration or higher polynomial effect; it fails to convey information about the magnitude of the difference between the group trajectories at specific time point. Thus, reporting and interpreting effect sizes have been increased emphases in HLGM in recent years, due to the limitations and increased criticisms for statistical hypothesis testing. However, most researchers fail to report these model-implied effect sizes for group trajectories comparison and their corresponding confidence intervals in HLGM analysis, since lack of appropriate and standard functions to estimate effect sizes associated with the model-implied difference between grouping trajectories in HLGM, and also lack of computing packages in the popular statistical software to automatically calculate them. ^ The present project is the first to establish the appropriate computing functions to assess the standard difference between grouping trajectories in HLGM. We proposed the two functions to estimate effect sizes on model-based grouping trajectories difference at specific time, we also suggested the robust effect sizes to reduce the bias of estimated effect sizes. Then, we applied the proposed functions to estimate the population effect sizes (d ) and robust effect sizes (du) on the cross-level interaction in HLGM by using the three simulated datasets, and also we compared the three methods of constructing confidence intervals around d and du recommended the best one for application. At the end, we constructed 95% confidence intervals with the suitable method for the effect sizes what we obtained with the three simulated datasets. ^ The effect sizes between grouping trajectories for the three simulated longitudinal datasets indicated that even though the statistical hypothesis test shows no significant difference between grouping trajectories, effect sizes between these grouping trajectories can still be large at some time points. Therefore, effect sizes between grouping trajectories in HLGM analysis provide us additional and meaningful information to assess group effect on individual trajectories. In addition, we also compared the three methods to construct 95% confident intervals around corresponding effect sizes in this project, which handled with the uncertainty of effect sizes to population parameter. We suggested the noncentral t-distribution based method when the assumptions held, and the bootstrap bias-corrected and accelerated method when the assumptions are not met.^

Contributions to traditional electronic voting systems in order to reinforce citizen confidence

This document provides a general description of the telematic voting scenario designed by the author?s research group. This scenario reinforces verification procedures as key elements to achieve full acceptance of the system on the part of voters. To frame this work, a general overview of electronic voting is given and the conditions entailed by these systems are specified.

Confidence: dependencies and their critical role in fostering user acceptance in pervasive applications

Pervasive computing offers new scenarios where users are surrounded by invisible and proactive technology making smart spaces. Although the utility and power of solutions developed using this computer paradigm are proved, there are unresolved problems that hinder their acceptance and inclusion in our private life. Users have problems understanding the operations of a pervasive computing solution, and therefore they should trust that the solution works properly and according to their expectations. Nevertheless, the concept of trust is already framed in a specific use within the ecosystem of applications that can populate a smart space. To take this concept of trust to the whole space, we propose to study and define the concept of confidence. In contrast to the concept of trust, confidence has deeper psychological implications.

Let's Gain More Confidence Of Clinicians With Our Colorful Contours: Blood Flow Simulation In Arteries Using Abaqus & STAR-CCM+

The objective of the current work is to present the results of several numerical simulations of pulsatile blood flow in healthy and diseased arteries and compare with clinical expectations. Different realistic and physiological aspects such as blood flow interaction with arterial walls, effect of heart movement, cardiovascular autoregulation, arterial walls' hyperelasticity and cardiovascular disorders have been incorporated in the models thanks to a direct coupling of Abaqus and STAR-CCM+. Comparisons of implicit and explicit coupling methods in cardiovascular simulations have been discussed. An in-house methodology combined with explicit FSI coupling has reduced considerably calculation time while the simulations stay realistic and reliable for clinicians

Accessible interaction solution based on confidence for the deployment of pervasive sensitive services in intelligent environments

Los servicios basados en las Tecnologías de la Información y las Comunicaciones (TIC) están cada vez más presentes en la vida de las personas. El avance de las TIC en términos técnicos y de aceptación social ha dado lugar la creación de nuevos modelos de provisión de servicios. Estos modelos de servicio implican una mayor integración con las actividades de las personas de forma que ya no solo están presentes en su ámbito profesional o de espacio ciudadano sino también en un ámbito más íntimo relacionado con su propia identidad. Así en la actualidad es común encontrar servicios conocedores del estado de salud de las personas, sus hábitos domésticos, su ideología, etc. Por tanto el análisis de los servicios actuales no puede limitarse a una componente técnica sino que es más necesario que nunca la inclusión de aspectos más relacionados con la forma de ser y sentir de sus usuarios. De esta forma no solo se garantizará la corrección técnica de sus funcionalidades sino que también se fomentará la generación de soluciones cívicamente seguras y respetuosas tanto con los derechos como con la forma de ser y sentir de sus usuarios. Desde el punto de vista de ingeniería, la perspectiva del usuario se ha englobado históricamente bajo el concepto de aceptación tecnológica. Dentro de este ámbito se puede interpretar que soluciones respetuosas y adaptadas a los usuarios fomentarán la aceptación por parte de éstos. La aceptación de una solución es algo deseable si bien es difícil de asegurar. Esta dificultad es debida al desconocimiento del número de variables que afectan a la aceptación de soluciones tecnológicas y a la dificultad de optimización de las variables conocidas. En esta tesis doctoral se estudia y caracteriza una de las variables que afecta a la aceptación de los servicios actuales: la confianza. Se define la confianza en términos psicológicos caracterizándola para permitir su uso en los métodos propios de la ingeniería. Además se proponen distintas herramientas que facilitan la optimización de la confianza en servicios cuya complejidad convierte a esta variable en una cuestión básica para mejorar la aceptación. Como contexto de trabajo para la tesis se ha escogido un servicio de salud desplegado en un hogar. Este escenario presenta una serie de restricciones de aceptación relativas a la tecnología utilizada para la creación de los servicios y la forma en que éstos gestionan la información adquirida del usuario. Se trata de servicios altamente sensibles y deslocalizados que pueden afectar a la percepción del usuario sobre el entorno, el hogar, y generar temores o rechazos que impidan su adopción final como solución válida. Una vez definido el marco genérico de trabajo, el objetivo principal de esta tesis doctoral se concreta en contribuir al fomento de la aceptación de nuevos servicios de salud pervasivos y personalizados y su despliegue en entornos inteligentes domésticos mediante un marco de diseño que promueva un estado psicológico de confianza en los usuarios. Para lograr abordar correctamente este objetivo se han proporcionado una serie de resultados tanto a nivel conceptual como tecnológico y experimental. En concreto se ha ofrecido una caracterización completa del sentimiento de confianza desde un punto de vista de ingeniería y una definición del concepto de servicio sensible deslocalizado o pervasivo. Además se ofrece un método para la inclusión del Diseño de Interacción, herramienta muy relacionada con la mejora de las variables de aceptación de tecnología, en los procesos de ingeniería de este tipo de servicios mediante un conjunto de patrones de interacción Persona – Entorno Inteligente. Finalmente se ha proporcionado el desarrollo de una arquitectura software para garantizar el correcto despliegue de estos servicios sensibles pervasivos en espacios inteligentes de una forma confiable. La discusión de los resultados obtenidos sugiere la extensión del modelo a diferentes servicios de la Sociedad de la Información que manejen datos sensibles tanto en el contexto del Hogar Digital como otros contextos donde el usuario realice actividades cotidianas, como los espacios de trabajo o los centros educativos. Las líneas de trabajo futuras contemplan la necesidad inminente de aplicar los resultados a desarrollos en curso, dentro de proyectos de investigación en los que participa el autor así como el desarrollo de nuevas líneas de investigación orientadas a la generación de nuevos espacios y tecnologías de interacción como el Colegio Digital, juguetes del futuro, sistemas de visualización confiables o sistemas de seguridad basados en el estado de las personas.