Trajectories of depressive symptoms after hip fracture

BACKGROUND: Hip fracture is often complicated by depressive symptoms in older adults. We sought to characterize trajectories of depressive symptoms arising after hip fracture and examine their relationship with functional outcomes and walking ability. We also investigated clinical and psychosocial predictors of these trajectories. METHOD: We enrolled 482 inpatients, aged ≥60 years, who were admitted for hip fracture repair at eight St Louis, MO area hospitals between 2008 and 2012. Participants with current depression diagnosis and/or notable cognitive impairment were excluded. Depressive symptoms and functional recovery were assessed with the Montgomery–Asberg Depression Rating Scale and Functional Recovery Score, respectively, for 52 weeks after fracture. Health, cognitive, and psychosocial variables were gathered at baseline. We modeled depressive symptoms using group-based trajectory analysis and subsequently identified correlates of trajectory group membership. RESULTS: Three trajectories emerged according to the course of depressive symptoms, which we termed ‘resilient’, ‘distressed’, and ‘depressed’. The depressed trajectory (10% of participants) experienced a persistently high level of depressive symptoms and a slower time to recover mobility than the other trajectory groups. Stressful life events prior to the fracture, current smoking, higher anxiety, less social support, antidepressant use, past depression, and type of implant predicted membership of the depressed trajectory. CONCLUSIONS: Depressive symptoms arising after hip fracture are associated with poorer functional status. Clinical and psychosocial variables predicted membership of the depression trajectory. Early identification and intervention of patients in a depressive trajectory may improve functional outcomes after hip fracture

Observational Learning During Simulation-Based Training in Arthroscopy: Is It Useful to Novices?

This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this record.OBJECTIVE: Observing experts constitutes an important and common learning experience for surgical residents before operating under direct guidance. However, studies suggest that exclusively observing experts may induce suboptimal motor learning, and watching errors from non-experts performing simple motor tasks may generate better performance. We investigated whether observational learning is transferrable to arthroscopy learning using virtual reality (VR) simulation. SETTING/DESIGN: In our surgical simulation laboratory, we compared students learning basic skills on a VR arthroscopy simulator after watching an expert video demonstration of VR arthroscopy tasks or a non-expert video demonstration of the same tasks to a Control group without video demonstration. Ninety students in 3 observing groups (expert, non-expert, and Control) subsequently completed the same procedure on a VR arthroscopy simulator. We hypothesized the non-expert-watching group would outperform the expert-watching group, and both groups to outperform the Control group. We examined performance pretest, posttest, and 1 week later. PARTICIPANTS: Participants were recruited from the final year of medical school and the very early first year of surgical residency training programs (orthopaedic surgery, urology, plastic surgery, and general surgery) at Western University (Ontario, Canada). RESULTS: All participants improved their overall performance from pretest to retention (p < 0.001). At initial retention testing, non-expert-watching group outperformed the other groups in camera path length p < 0.05 and time to completion, p < 0.05, and both the expert/non-expert groups surpassed the Control group in camera path length (p < 0.05). CONCLUSION: We suggest that error-observation may contribute to skills improvement in the non-expert-watching group. Allowing novices to observe techniques/errors of other novices may assist internalization of specific movements/skills required for effective motor performances. This study highlights the potential effect of observational learning on surgical skills acquisition and offers preliminary evidence for peer-based practice (combined non-experts and experts) as a complementary surgical motor skills training strategy.This project was supported by a Physicians׳ Services Incorporated (PSI) Foundation, Canada grant. Funds were used to pay for salary and employee benefits (LvE). The PSI Foundation did not play a role in the investigation

Perspectivas de la investigación en antioxidantes en Colombia

El consumo mundial de productos alimenticios que brinden ventajas adicionales para la salud, es uno de los más dinámicos en el ámbito mundial. El concoimiento sobre las ventajas que ofrecen un número importante de frutas y hortalizas para ateder este mercado, puede motivar procesos de investigación y desarrollo tecnológico para que el sector agropecuario y agroindustrial mejore su competitividad

Accurate PpT Data for Methane from (300 to 450) K up to 180 MPa

This paper reports PFT data measured with a high-pressure, single-sinker, magnetic-suspension densimeter (MSD) from (300 to 450) K up to 180 MPa. Our MSD technique yields accurate data, with less than 0.05 % relative uncertainty, over the pressure range of (10 to 200) MPa. The experimental data compare well to the Setzmann and Wagner equation of state as implemented in RefProp 8.0. These methane density data are consistent with the low range of pressure predicted by RefProp 8.0 that has a relative uncertainty of 0.03 % up to 12 MPa and 0.07 % up to 50 MPa. The density predictions of this model agree well with previous data at higher pressures. The equation predicts data with almost the same uncertainty as the experimental data up to 180 MPa. These PFT data also allow reliable determination of both second and third virial coefficients

DIAGNOSIS AND ENVIRONMENTAL MANAGEMENT OF THE WATERSHED THE ESCORIAL, PAMPLONA MUNICIPALITY

En este artículo se presenta el proyecto de investigación desarrollado en la microcuenca Quebrada La Hoya Oscura, municipio Pamplona durante los meses de octubre, noviembre y diciembre de 2012, cuyo objetivo fue la determinación del índice de escasez de la microcuenca en estudio. Para ello, se recopilo información a partir de una encuesta aplicada a la comunidad del área de estudio para establecer la cantidad de habitantes, el número de animales, los usos del recurso hídrico, tipos de cultivos, etc; además, se realizó un levantamiento de información a partir de la visita de campo en la cual con la ayuda de instrumentos como GPS GARMINETREX 20, y GoogleEarth, Auto CAD civil 3D 2011 y el Mapsourse para realizar el levantamiento de la cuenc

Trainee-environment interactions that stimulate motivation:A rich pictures study

Staying motivated when working and learning in complex workplaces can be challenging. When complex environments exceed trainees' aptitude, this may reduce feelings of competence, which can hamper motivation. Motivation theories explain how intrapersonal and interpersonal aspects influence motivation. Clinical environments include additional aspects that may not fit into these theories. We used a systems approach to explore how the clinical environment influences trainees' motivation and how they are intertwined. We employed the rich pictures drawing method as a visual tool to capture the complexities of the clinical environment. A total of 15 trainees drew a rich picture representing a motivating situation in the workplace and were interviewed afterwards. Data collection and analysis were performed iteratively, following a constructivist grounded theory approach, using open, focused and selective coding strategies as well as memo writing. Both drawings and the interviews were used to reach our results. Trainees drew situations pertaining to tasks they enjoyed doing and that mattered for their learning or patient care. Four dimensions of the environment were identified that supported trainees' motivation. First, social interactions, including interpersonal relationships, supported motivation through close collaboration between health care professionals and trainees. Second, organisational features, including processes and procedures, supported motivation when learning opportunities were provided or trainees were able to influence their work schedule. Third, technical possibilities, including tools and artefacts, supported motivation when tools were used to provide trainees with feedback or trainees used specific instruments in their training. Finally, physical space supported motivation when the actual setting improved the atmosphere or trainees were able to modify the environment to help them focus. Different clinical environment dimensions can support motivation and be modified to create optimal motivating situations. To understand motivational dynamics and support trainees to navigate through postgraduate medical education, we need to take all clinical environment dimensions into account54324225

Modelamiento y simulación de un quadrotor mediante la integración de Simulink y SolidWorks

El propósito de este trabajo fue el de realizar el modelo dinámico de un vehículo aéreo no tripulado (VANT) tipo quadrotor, que simule el comportamiento real del mismo, de tal manera que el quadrotor pueda realizar sus movimientos básicos con el mínimo error posible. Para realizar dicho modelo matemático se consideró al quadrotor como un cuerpo rígido de seis grados de libertad en donde el sistema es dividido en coordenadas traslacionales y rotacionales al manejar una técnica para la modelación, mediante las ecuaciones de Euler-Lagrange, y así obtener la función de transferencia, expresada en las plantas del modelo dinámico que describe el comportamiento del quadrotor. La dinámica rotacional del VANT fue definida por los principales momentos de inercia, los cuales fueron hallados en el centro de masa del vehículo, dichos momentos fueron estimados a través del software de entorno CAD Solidworks. Para ello, el quadrotor se ensambló allí con el mínimo de partes posibles y luego el diseño se exportó a Simulink para complementar los resultados de la simulación con una animación en 3D del movimiento. Al diseño de la estructura se le implementó una estrategia de control que estabiliza las plantas ya descritas y se corroboró el funcionamiento del sistema al aplicar al mismo, perturbaciones externas como lo son las ráfagas de viento y masas variables que puedan producir inestabilidad durante el vuelo, logrando que ante este tipo de señales el sistema reaccione de forma controlada. En los resultados se observó que la simulación de una ráfaga de viento en donde el VANT cambio su posición en los ejes de desplazamiento horizontal, este mismo logró llegar nuevamente a su posición de referencia en menos de doce (12) segundos. Lo anterior constituye una importante aplicación de la dinámica rotacional del Vehículo Aéreo No Tripulado, al utilizar Simulink y la librería Simscape Multibody en conjunto con Solidworks, lográndose una herramienta de gran interés y por ende un aporte significativo para el estudio de los VANT, dando posibilidad del uso de una herramienta práctica para el diseño de quadrotores, enfocados en diferentes aplicaciones, tales como la agricultura de precisión

Bubble nucleation in polymer–CO_2 mixtures

We combine density-functional theory with the string method to calculate the minimum free energy path of bubble nucleation in two polymer–CO_2 mixture systems, poly(methyl methacrylate) (PMMA)–CO_2 and polystyrene (PS)–CO_2. Nucleation is initiated by saturating the polymer liquid with high pressure CO_2 and subsequently reducing the pressure to ambient condition. Below a critical temperature (Tc), we find that there is a discontinuous drop in the nucleation barrier as a function of increased initial CO_2 pressure (P0), as a result of an underlying metastable transition from a CO_2-rich-vapor phase to a CO_2-rich-liquid phase. The nucleation barrier is generally higher for PS–CO_2 than for PMMA–CO_2 under the same temperature and pressure conditions, and both higher temperature and higher initial pressure are required to lower the nucleation barrier for PS–CO2 to experimentally relevant ranges. Classical nucleation theory completely fails to capture the structural features of the bubble nucleus and severely underestimates the nucleation barrier