La fijación externa monolateral en el tratamiento de las fracturas femorales del niño: experiencia preliminar en 20 casos

Veinte niños con fracturas femorales diafisarias simples fueron tratados mediante fijación externa con el aparato de Wagner. Once eran niños y 9 niñas, con una edad media de 8 años (3-15). Doce fracturas eran mediodiafisarias, 6 en el tercio proximal y 2 en el tercio distal. La hospitalización media fue de 9 días (5-20). La duración media de fijación externa fue de 61 días. Cinco casos precisaron de algún tratamiento adicional. En 3 pacientes se detectó una infección en el trayecto de los clavos y 1 de ellos necesitó retirada prematura del aparato. La movilidad articular de la rodilla se restableció de modo completo y constante excepto en 1 caso. En los casos seguidos más de 18 meses se observó un hipercrecimiento medio del fémur fracturado de 0,8 cm (0,5- 1,5). No hubo desaxaciones ni malrotaciones. Las ventajas de la fijación externa en el tratamiento de las fracturas femorales del niño incluyen Un mejor control de los fragmentos fracturarlos, una menor hospitalización y un cuidado más fácil y confortable de los pacientes. La infección del trayecto de los clavos parece ser la complicación más seria. En esta serie se detectó una curva de aprendizaje.Twenty children with simple femoral-shaft fractures were treated by monolateral external fixation with the Wagner device. There were 11 boys and 9 girls with a mean age of 8 years (3-15). Twelve fractures were located at the midshaft, 6 at the proximal third, and 2 other at the distal third of the femur. The mean hospital stay was 9 days (5-20). Mean external fixation time was 61 years. In 5 cases, additional methods of treatment were required. Pin tract infection occurred in 3 cases (one needed premature removal of the device). Except for one case, full range of knee motion was usually achieved after treatment. In patients followed for more than 18 months, a mean femoral overgrowth of 0.8 cm (0.5-1.5) was detected. Neither angular deformities nor malrotations were observed. In our experience, the main advantages of external fixation for femoral-shaft fractures in children include less hospitalization time and an easier and more confortable nursing. External fixation allows a better control of the bone fragments, providing an adequate stability. Pin tract infection seems to be the most important drawback. A learning curve was observed in this series

Some properties of Multiplication Operators acting on Banach spaces of measurable functions

The purpose of this article is to survey the recent results about the properties of multiplication operators acting on Banach spaces of measurable functions. Most of them was presented by the author in a conference held in Bogotá 2016, on the occasion of celebrating the "IV UN Encuentro de Matemáticas" at the "Universidad Nacional de Colombia"

A tool assisting teachers in automating the assessment of programming assignments

Automating the assessment of programming assignments brings benefits for both students and teachers, since it helps the formers to gain a timely feedback and releases the latter from tedious tasks. The related literature in the domain has usually focused on the assessment process and the tools required for it, proposing libraries and systems that teachers can use in this process. However, few of them have work rowards reducing the effort and time teacher require to properly set up new assessente processes. This paper describes our experience with the analysis and design of a new tool to support teachers in visually developing automatic grades of programming assignments, introducing the underlying concepts and technologies and presenting the system architecture

Effect of adhesive thickness and concrete strength on FRP-Concrete Bonds

The use of fiber-reinforced polymer (FRP) composites for strengthening, repairing, or rehabilitating concrete structures has become more and more popular in the last 10 years. Irrespective of the type of strengthening used, design is conditioned, among others, by concrete-composite bond failure, normally attributed to stress at the interface between these two materials. Single shear, double shear, and notched beam tests are the bond tests most commonly used by the scientific community to estimate bond strength, effective length, and the bond stress-slip relationship. The present paper discusses the effect of concrete strength and adhesive thickness on the results of beam tests, which reproduce debonding conditions around bending cracks much more accurately. The bond stress-slip relationship was analyzed in a cross section near the inner edge, where stress was observed to concentrate. The ultimate load and the bond stress-slip relationship were visibly affected by concrete strength. Adhesive thickness, in turn, was found to have no significant impact on low-strength concrete but a somewhat greater effect on higher strength materials

Robust Timing Synchronization for Multicarrier Systems Based on RST Invariance

In this paper, a blind robust timing synchronization method, based on invariance properties and cyclostationarity, for multicarrier systems such as Orthogonal Frequency Division Multiplexing (OFDM) is proposed and evaluated. Its results outperform the state-of-the-art for blind methods, specially in hard wireless channels where our proposal is highly superior. It even surpasses the performance of most of non-blind (pilot-aided) methods, while at the same time, it gets the advantages of energy and bandwidth saving of blind proposals. Moreover, since this technique does not require the use of pilots, it can be easily applied to either packet-based or broadcasting systems.This work has been partly funded by the Spanish national projects GRE3N-SYST (TEC2011-29006-C03-03) and COMONSENS (CSD2008-00010).Publicad

Desempenho estudantil acadêmico na parte inicial da carreira de Doutor em Medicina da Universidade da República

Adriana Fernández-Álvarez: Departamento de Educación Médica, Facultad de Medicina, Universidad de la República. Coordinación del Ciclo Básico Clínico Comunitario, Unidad de Coordinación Curricular, Facultad de Medicina, Universidad de la República, Uruguay.-- Julio C. Siciliano: Departamento de Histología y Embriología, Facultad de Medicina, Universidad de la República, Uruguay. Coordinación del Ciclo Básico Clínico Comunitario, Unidad de Coordinación Curricular, Facultad de Medicina, Universidad de la República, Uruguay.-- Contacto: Adriana Fernández-Álvarez. E-mail: [email protected] este trabajo se presentan los resultados de una indagación de carácter diagnóstico acerca del desempeño académico de los estudiantes de Medicina en los cursos y exámenes correspondientes al ciclo Básico Clínico Comunitario (semestres 2 al 6 de la carrera) en el lapso 2009 a 2016. Los datos correspondientes a inscripciones, aprobaciones y no aprobaciones de cursos y exámenes se obtuvieron y sistematizaron a partir de fuentes secundarias oficiales de origen institucional. Se realizó un análisis cuantitativo ex-post en un estudio de tipo descriptivo que incluyó análisis estadístico inferencial en uno de sus ítems. El análisis evidenció que: I) en la evaluación de los exámenes predomina como resultado la no aprobación sin embargo en la evaluación de cursos predomina la aprobación; II) recursar tras renunciar a cursos aprobados no mejora el desempeño estudiantil en los cursos; III) el desempeño en cursos y exámenes de una cohorte es superior en los estudiantes que aprueban el examen final de BCC1 en el primer o segundo período que en quienes no lo hacen (test χ2; p < 0,001). Además, existió asociación positiva entre aprobar BCC1 en el primer o segundo período y la aprobación de mayor cantidad de cursos (V de Cramer 0,508; p < 0,001) y exámenes (V de Cramer según períodos 0,813 y 0,727; p < 0,001) en el tramo de carrera considerado. Estos datos constituyen un insumo para la evaluación de la implementación del plan de estudios y de la necesidad eventual de realizar ajustes a la normativa vigente.This paper presents the results of aresearch that deals with the academic performance of medical students in the courses and exams corresponding to semesters from 2 to 6 of medical school, which includes basic, clinical and community studies. Data about enrollment, approval and non-approval of courses and exams, between 2009 and 2016, were obtained and systematized from official sec-ondary sources of institutional origin. A quantitative ex-post analysis was performed in a descriptive study that included inferential statistical analysis in one of its items. Results showed:I) non-approval condition predominates in the exams califications, however, approval condition predominates at the courses evaluations; II) recoursing after renouncing to a previously approved course does not improve performance; III)performance in courses and exams of a cohort is better in those students who ap-proved the final exam of BCC1 immediately after course than in those that did not (test χ; p < 0,001). In addition, it was detected a positive association between approving BCC1 immediately after course and the approval of a greater number of courses (Cramer ́s V 0.508, p < 0.001) and exams (Cramer ́s V according to periods 0.813 and 0.727, p < 0.001) in the considered lapse at medical school. These data will be useful for the evaluation of the curriculum structure implementation and for an eventual adjustment of the current regulations.Este artigo apresenta os resultados de um inquérito de diagnóstico sobre o desempenho acadêmico dos estudantes de medicina nos cursos e exames correspondentes ao ciclo clínico comunitário bási-co (semestres 2 a 6 do curso) no período de 2009 a 2016. Os dados para inscrição, aprovação e não aprovação de cursos e exames foram obtidos e sistematizados a partir de fontes secundárias oficiais de origem institucional. Uma análise quantitativa ex-post foi realizada em um estudo descritivo que incluía análise estatística inferencial em um de seus itens. A análise mostrou que: I) na avaliação dos exames, a não aprovação predomina como resultado, no entanto, na avaliação dos cursos, a aprovação predomina; II) voltar a cursar cursos já aprovados não melhora o desempenho dos alunos nos cursos; III) o desempenho em cursos e exames de uma coorte é maior nos alunos que passam o exame BCC1 final no primeiro ou segundo período do que naqueles que não (teste χ2; p <0,001). Além disso, houve associação positiva entre a aprovação de BCC1 no primeiro ou segundo período e a aprovação de mais cursos (Cramer V 0.508; p <0.001) e exames (Cramer V de acordo com os períodos 0.813 e 0.727; p <0.001) no trecho considerado. Esses dados constituem um insumo para a avaliação da implementa-ção do currículo e a eventual necessidade de fazer ajustes aos regulamentos vigentes