To fail is human: remediating remediation in medical education.

IntroductionRemediating failing medical learners has traditionally been a craft activity responding to individual learner and remediator circumstances. Although there have been moves towards more systematic approaches to remediation (at least at the institutional level), these changes have tended to focus on due process and defensibility rather than on educational principles. As remediation practice evolves, there is a growing need for common theoretical and systems-based perspectives to guide this work.MethodsThis paper steps back from the practicalities of remediation practice to take a critical systems perspective on remediation in contemporary medical education. In doing so, the authors acknowledge the complex interactions between institutional, professional, and societal forces that are both facilitators of and barriers to effective remediation practices.ResultsThe authors propose a model that situates remediation within the contexts of society as a whole, the medical profession, and medical education institutions. They also outline a number of recommendations to constructively align remediation principles and practices, support a continuum of remediation practices, destigmatize remediation, and develop institutional communities of practice in remediation.DiscussionMedical educators must embrace a responsible and accountable systems-level approach to remediation if they are to meet their obligations to provide a safe and effective physician workforce

Characterizing steady states of genome-scale metabolic networks in continuous cell cultures

We present a model for continuous cell culture coupling intra-cellular metabolism to extracellular variables describing the state of the bioreactor, taking into account the growth capacity of the cell and the impact of toxic byproduct accumulation. We provide a method to determine the steady states of this system that is tractable for metabolic networks of arbitrary complexity. We demonstrate our approach in a toy model first, and then in a genome-scale metabolic network of the Chinese hamster ovary cell line, obtaining results that are in qualitative agreement with experimental observations. More importantly, we derive a number of consequences from the model that are independent of parameter values. First, that the ratio between cell density and dilution rate is an ideal control parameter to fix a steady state with desired metabolic properties invariant across perfusion systems. This conclusion is robust even in the presence of multi-stability, which is explained in our model by the negative feedback loop on cell growth due to toxic byproduct accumulation. Moreover, a complex landscape of steady states in continuous cell culture emerges from our simulations, including multiple metabolic switches, which also explain why cell-line and media benchmarks carried out in batch culture cannot be extrapolated to perfusion. On the other hand, we predict invariance laws between continuous cell cultures with different parameters. A practical consequence is that the chemostat is an ideal experimental model for large-scale high-density perfusion cultures, where the complex landscape of metabolic transitions is faithfully reproduced. Thus, in order to actually reflect the expected behavior in perfusion, performance benchmarks of cell-lines and culture media should be carried out in a chemostat

A Hierachical Evolutionary Algorithm for Multiobjective Optimization in IMRT

Purpose: Current inverse planning methods for IMRT are limited because they are not designed to explore the trade-offs between the competing objectives between the tumor and normal tissues. Our goal was to develop an efficient multiobjective optimization algorithm that was flexible enough to handle any form of objective function and that resulted in a set of Pareto optimal plans. Methods: We developed a hierarchical evolutionary multiobjective algorithm designed to quickly generate a diverse Pareto optimal set of IMRT plans that meet all clinical constraints and reflect the trade-offs in the plans. The top level of the hierarchical algorithm is a multiobjective evolutionary algorithm (MOEA). The genes of the individuals generated in the MOEA are the parameters that define the penalty function minimized during an accelerated deterministic IMRT optimization that represents the bottom level of the hierarchy. The MOEA incorporates clinical criteria to restrict the search space through protocol objectives and then uses Pareto optimality among the fitness objectives to select individuals. Results: Acceleration techniques implemented on both levels of the hierarchical algorithm resulted in short, practical runtimes for optimizations. The MOEA improvements were evaluated for example prostate cases with one target and two OARs. The modified MOEA dominated 11.3% of plans using a standard genetic algorithm package. By implementing domination advantage and protocol objectives, small diverse populations of clinically acceptable plans that were only dominated 0.2% by the Pareto front could be generated in a fraction of an hour. Conclusions: Our MOEA produces a diverse Pareto optimal set of plans that meet all dosimetric protocol criteria in a feasible amount of time. It optimizes not only beamlet intensities but also objective function parameters on a patient-specific basis

Mathematical Models of the Impact of IL2 Modulation Therapies on T Cell Dynamics

Several reports in the literature have drawn a complex picture of the effect of treatments aiming to modulate IL2 activity in vivo. They seem to promote either immunity or tolerance, probably depending on the specific context, dose, and timing of their application. Such complexity might derive from the pleiotropic role of IL2 in T cell dynamics. To theoretically address the latter possibility, our group has developed several mathematical models for Helper, Regulatory, and Memory T cell population dynamics, which account for most well-known facts concerning their relationship with IL2. We have simulated the effect of several types of therapies, including the injection of: IL2; antibodies anti-IL2; IL2/anti-IL2 immune-complexes; and mutant variants of IL2. We studied the qualitative and quantitative conditions of dose and timing for these treatments which allow them to potentiate either immunity or tolerance. Our results provide reasonable explanations for the existent pre-clinical and clinical data, predict some novel treatments, and further provide interesting practical guidelines to optimize the future application of these types of treatments

Six questions on the construction of ontologies in biomedicine

(Report assembled for the Workshop of the AMIA Working Group on Formal Biomedical Knowledge Representation in connection with AMIA Symposium, Washington DC, 2005.) Best practices in ontology building for biomedicine have been frequently discussed in recent years. However there is a range of seemingly disparate views represented by experts in the field. These views not only reflect the different uses to which ontologies are put, but also the experiences and disciplinary background of these experts themselves. We asked six questions related to biomedical ontologies to what we believe is a representative sample of ontologists in the biomedical field and came to a number conclusions which we believe can help provide an insight into the practical problems which ontology builders face today

Guidelines: The dos, don'ts and don't knows of remediation in medical education.

INTRODUCTION: Two developing forces have achieved prominence in medical education: the advent of competency-based assessments and a growing commitment to expand access to medicine for a broader range of learners with a wider array of preparation. Remediation is intended to support all learners to achieve sufficient competence. Therefore, it is timely to provide practical guidelines for remediation in medical education that clarify best practices, practices to avoid, and areas requiring further research, in order to guide work with both individual struggling learners and development of training program policies. METHODS: Collectively, we generated an initial list of Do's, Don'ts, and Don't Knows for remediation in medical education, which was then iteratively refined through discussions and additional evidence-gathering. The final guidelines were then graded for the strength of the evidence by consensus. RESULTS: We present 26 guidelines: two groupings of Do's (systems-level interventions and recommendations for individual learners), along with short lists of Don'ts and Don't Knows, and our interpretation of the strength of current evidence for each guideline. CONCLUSIONS: Remediation is a high-stakes, highly complex process involving learners, faculty, systems, and societal factors. Our synthesis resulted in a list of guidelines that summarize the current state of educational theory and empirical evidence that can improve remediation processes at individual and institutional levels. Important unanswered questions remain; ongoing research can further improve remediation practices to ensure the appropriate support for learners, institutions, and society

Presentación de estados financieros basados en decreto 2649 y NIIF

En el presente trabajo se realiza un análisis sistemático de literatura con revisiones literarias, sobre los cambios o modificaciones que han sufrido los estados financieros o la presentación de estos para una organización. Lo que se busca con el presente análisis y concluir los cambios más significativos que se presentan en los Estados Financieros de una organización desde la entrada de las Normas Internacionales De Información Financiera. Para la elaboración del análisis se observaron diferentes textos de autores sobre las modificaciones que sufren los Estados Financieros con las NIIF, en busca de las conclusiones mencionadas, pasando por comparar la presentación de estos estados antes y después de la inclusión de las NIIF. Identificar los cambios de los Estados financieros basados en las NIIF es el objetivo general y central del análisis, en donde específicamente se busca caracterizar la preparación de los estados antes de las NIIF, es decir cómo era la preparación y presentación con la Norma 2649, y luego como es con las NIIF. El análisis se desarrolló bajo un método descriptivo, es decir se buscaron autores que describieran o caracterizaran la preparación de los estados financieros con cada una de las normativas expuestas para llegar a una conclusión y recomendaciones del tema.In the present work a systematic analysis of literature is carried out with literary reviews, on the changes or modifications that the financial statements have suffered or the presentation of these for an organization. What is sought with this analysis and conclude the most significant changes that are presented in the financial statements of an organization since the entry of International Financial Reporting Standards. For the elaboration of the analysis, different texts of authors were observed on the modifications that the Financial Statements undergo with the IFRS, in search of the mentioned conclusions, going on to compare the presentation of these statements before and after the inclusion of the IFRS. Identifying the changes in financial statements based on IFRS is the general and central objective of the analysis, which specifically seeks to characterize the preparation of the statements before the IFRS, that is, how the preparation and presentation was with the Standard 2649, and then as it is with IFRS. The analysis was developed under a descriptive method, that is to say, authors were searched to describe or characterize the preparation of the financial statements with each of the exposed regulations in order to reach a conclusion and recommendations on the subject.RESUMEN ABSTRACS 0. INTRODUCCIÓN9 2. PLANTEAMIENTO PROBLEMA11 3. JUSTIFICACIÓN12 4. OBJETIVOS DE LA REVISIÓN13 4.1 OBJETIVO GENERAL13 4.2 OBJETIVOS ESPECIFICOS13 5. METODOLOGIA14 5.1 TIPO DE INVESTIGACIÓN14 5.2 DISEÑO INVESTIGACIÓN15 5.3 TECNICAS DE INVESTIGACIÓN15 6. RESULTADOS DE LA REVISION REALIZADA17 7. ANALISIS Y DISCUSIÓN DE LA REVISIÓN25 8. CONCLUSIONES27 9. RECOMENDACIONES28 10. REFERENCIA BIBLIOGRAFICA2