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espanolObjetivo: Validar una metodologia computacionalmente eficiente para resolver el problema de despacho economico multiperiodo estocastico con restricciones de seguridad. Metodologia: Se utilizan factores lineales de sensibilidad para calcular flujos de carga de forma rapida y precisa. Tambien se usa un metodo iterativo, que identifica y agrega como cortes de usuario, las restricciones de seguridad activas. Estas restricciones establecen la region factible de un modelo embebido dentro de un algoritmo Progressive Hedging, el cual descompone el problema principal en un conjunto de sub-problemas computacionalmente mas tratables, al relajar las restricciones de acoplamiento entre escenarios. Resultados: Los resultados numericos sobre el sistema IEEE RTS96, muestran que la estrategia propuesta entrega soluciones de alta calidad en bajos tiempos de calculo. Conclusiones: La metodologia propuesta permite solucionar el despacho economico multiperiodo estocastico seguro hasta 50 veces mas rapido cuando se compara con su formulacion extensiva. EnglishObjective: Validate a computationally efficient approach to solve the stochastic security constraint unit commitment problem. Methodology: Linear sensitivity factors are used to compute power flows in a fast and accurate way. It is also used an iterative method that identifies and adds as user cuts the set of active constraints. These constraints establish the feasible region of a model embedded within a Progressive Hedging algorithm, which decomposes the main problem into a set of computationally more tractable sub-problems by relaxing the coupling constraints between scenarios. Results: The numerical results on the IEEE RTS96 system show that the proposed strategy provides high quality solutions with low calculation times. Conclusions: The proposed methodology allows the stochastic security-constraint unit commitment problem to be solved up to 50 times faster when compared to its extensive formulation.

espanolEl problema de despacho economico multiperiodo (DEM) consiste en determinar de manera optima que unidades de generacion deben suministrar potencia al sistema en un horizonte de tiempo tipico de 24 horas. El DEM con restricciones de seguridad (SCUC por sus siglas en ingles) es un problema de alto costo computacional debido a la cantidad y naturaleza de las variables involucradas. En este articulo se presenta una formulacion alternativa del SCUC para reducir su costo computacional, mediante el uso de los factores de sensibilidad PTDF y LODF. En contraste con las formulaciones clasicas, el uso de estos factores permite calcular flujos de carga sin necesidad de utilizar los angulos nodales, reduciendo el numero de variables y restricciones del modelo. Ademas, se implementa una metodologia de filtro de contingencias activas N-1 que reduce aun mas la carga computacional, a traves de cortes de usuario. Se presentan resultados para el sistema IEEE-RTS96 que evidencian la robustez y aplicabilidad del modelo propuesto. Se encontro que el uso de los factores de sensibilidad PTDF y LODF, en conjunto con la metodologia de filtros de contingencias, reduce el costo computacional hasta en un 86% con respecto a su formulacion convencional. Adicionalmente, la metodologia propuesta identifica que lineas son mas vulnerables debido a sobrecargas, y cuales lineas causan mayores impactos al sistema cuando fallan. EnglishThe unit commitment (UC)problemconsists in optimally determining which generation units must supply power to the system in a typical time horizon of 24 hours. The security-constrained unit commitment (SCUC) is a problem of high computational cost due to the quantity and nature of the variables involved. This paper presents an alternative formulation of the SCUC to reduce its computational cost, by using the PTDF and LODF sensitivity factors. In contrast toclassic formulations, the use of these factors allows calculating powerflows without using nodal angles, reducing the number of variables and constraints of the model. In addition, an N-1 active contingency filter methodology is implemented that further reduces the computational burden through user cuts. Results are presented for theIEEE-RTS96 system that demonstrates the robustness and applicability of the proposed approach. It was found that the use of PTDF and LODF sensitivity factors, in conjunction with the contingency filter methodology, reduces the computational cost by up to 86% with respect to its conventional formulation. Additionally, the proposed methodology identifies which lines are more vulnerable due to overloads, and which lines cause the greatest impacts to the system when they fail.

Mendelian susceptibility to mycobacterial disease is a rare clinical condition characterized by a predisposition to infectious diseases caused by poorly virulent mycobacteria. Other infections such as salmonellosis and candidiasis are also reported. The purpose of this article is to describe a young boy affected with various infectious diseases caused by Mycobacterium tuberculosis complex, Salmonella sp, Klebsiella pneumonie, Citrobacter sp., and Candida sp, complicated with severe enteropathy and transient hypogammaglobulinemia. We reviewed medical records and performed flow cytometry staining for lymphocyte populations, lymphocyte proliferation in response to PHA, and intracellular IFN-γ production in T cell PHA blasts in the patient and a healthy control. Sanger sequencing was used to confirm the genetic variants in the patient and relatives. Genetic analysis revealed a bi-allelic mutation in IL12RB1 (C291Y) resulting in complete IL-12Rβ1 deficiency. Functional analysis demonstrated the lack of intracellular production of IFN-γ in CD3+ T lymphocytes from the patient in response to rhIL-12p70. To our knowledge, this is the third patient with MSMD due to IL-12Rβ1 deficiency complicated with enteropathy and hypogammaglobulinemia and the first case of this disease to be described in Colombia.