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 Precise Electrical Disturbance Generator for Neural Network Training with Real Level Output

Power Quality is defined as the study of the quality of electric power lines. The detection and classification of the different disturbances which cause power quality problems is a difficult task which requires a high level of engineering expertise. Thus, neural networks are usually a good choice for the detection and classification of these disturbances. This paper describes a powerful tool, developed by the Institute for Natural Resources and Agrobiology at the Scientific Research Council (CSIC) and the Electronic Technology Department at the University of Seville, which generates electrical patterns of disturbances for the training of neural networks for PQ tasks. This system has been expanded to other applications (as comparative test between PQ meters, or test of effects of power-line disturbances on equipment) through the addition of a specifically developed high fidelity power amplifier, which allows the generation of disturbed signals at real levels.Ministerio de Ciencia y Tecnología DPI2006-15467-C02-0

Estudio de soluciones existentes en el mercado para la inspección y mantenimiento de líneas eléctricas de alta tensión.

Este paper mostrará algunos de los métodos utilizados en robótica hoy en día para la inspección y revisión de líneas eléctricas. Además,explicaremos los procedimientos empleados para la realización de esta tarea, así como nuevos modelos y prototipos implementados recientemente para una mayor eficiencia

OLIMPO, An Ad-Hoc Wireless Sensor Network Simulator for Public Utilities Applications

This paper introduces OLIMPO, an useful simulation tool for researchers who are developing wireless sensor communication protocols. OLIMPO is a discreteevent simulator design to be easily recon gured by the user, providing a way to design, develop and test communication protocols. In particular, we have designed a self-organizing wireless sensor network for low data rate. Our premise is that, due to their inherent spread location over large areas, wireless sensor networks are well-suited for SCADA applications, which require relatively simple control and monitoring. To show the facilities of our simulator, we have studied our network protocol with OLIMPO, developing several simulations. The purpose of these simulations is to demonstrate, quantitatively, the capability of our network to support this kind of applications

Remoção de íons de metais pesados com bentonitas modificadas

O presente trabalho apresenta o desenvolvimento de um material sorvente a partir de bentonitas brasileiras modificadas quimicamente com o objetivo de aumentar sua capacidade de sorção de metais pesados e seu valor agregado. O estudo insere-se na área de tratamento de efluentes líquidos usando sorventes não tradicionais, eficientes e de baixo custo em substituição ao carvão ativado ou às resinas de troca iônica. As modificações foram realizadas via homoionização com cloreto de cálcio e posterior intercalação com compostos orgânicos com ação quelante de metais. Os melhores resultados de remoção de íons cobre, superiores a 95%, foram obtidos em pH 8 com as bentonitas modificadas com 1,1 Fenantrolina e com Etilenodiamina. A capacidade de acumulação alcançada, 107,53 mg de Cu/g de bentonita, é muito superior à de outros materiais sorventes alternativos propostos em estudos similares. Foi comprovada ainda a sorção em flocos (obtidos com polímeros solúveis), que permite realizar em uma etapa a remoção de íons e a separação sólido/líquido. Os resultados são discutidos em termos dos fenômenos interfaciais envolvidos e dos potenciais práticos deste novo sorvente e da nova técnica de sorção em flocos.O presente trabalho apresenta o desenvolvimento de um material sorvente a partir de bentonitas brasileiras modificadas quimicamente com o objetivo de aumentar sua capacidade de sorção de metais pesados e seu valor agregado. O estudo insere-se na área de tratamento de efluentes líquidos usando sorventes não tradicionais, eficientes e de baixo custo em substituição ao carvão ativado ou às resinas de troca iônica. As modificações foram realizadas via homoionização com cloreto de cálcio e posterior intercalação com compostos orgânicos com ação quelante de metais. Os melhores resultados de remoção de íons cobre, superiores a 95%, foram obtidos em pH 8 com as bentonitas modificadas com 1,1 Fenantrolina e com Etilenodiamina. A capacidade de acumulação alcançada, 107,53 mg de Cu/g de bentonita, é muito superior à de outros materiais sorventes alternativos propostos em estudos similares. Foi comprovada ainda a sorção em flocos (obtidos com polímeros solúveis), que permite realizar em uma etapa a remoção de íons e a separação sólido/líquido. Os resultados são discutidos em termos dos fenômenos interfaciais envolvidos e dos potenciais práticos deste novo sorvente e da nova técnica de sorção em flocos

Cultural democracy and promises of money. Cultural policies and arm’s length in the English-speaking world today (II)

En esta segunda parte del texto iniciado en el anterior número de Periférica (nº 18: https://revistas.uca.es/index. php/periferica/article/view/4182), recordando algunos de los extremos señalados en aquél, vamos destacar algunos factores singulares de la situación de las políticas culturales en Gran Bretaña., desde el final de la II Guerra Mundial hasta hoy. Para ello repasaremos las dos grandes tendencias del pensamiento político respecto al papel de la cultura en el bienestar de la ciudadanía: Democracia cultural o democratización de la cultura en sus diversas variables. Abordaremos el papel crucial de los Estudios Culturales en la configuración de este debate y la actualidad de algunas de sus ideas motoras. Resumiremos la función de algunas de las organizaciones encargadas de la gestión de la cultura y mencionaremos la singularidad de su articulación. Haremos mención, además, al papel central en la continuidad de ciertas políticas de acceso y en la definición de los nuevos discursos hegemónicos del siglo XXI de las grandes Corporaciones metropolitanas. Trataremos de llamar la atención sobre el papel de algunos actores (si, generalmente en masculino, con dos notables excepciones), de los cambios en la política cultural en los gobiernos laboristas de Wilson/ Blair y en el conservador de Thatcher, recordando la llegada ‒para quedarse‒ del discurso de las industrias creativas y describiendo el panorama ahora mismo del debate cultural en el país. Una tarea que, como en el primer trabajo, excluye numerosos asuntos de complejidad imposible de tratar en este espacio (las políticas territoriales diferenciadas de Escocia, Gales o Irlanda del Norte, por ejemplo).In this second instalment of the text (for part one, see Periférica nº 18: https://revistas.uca.es/index.php/periferica/ article/view/4182), I return to some of the extremes indicated in the first part in order to highlight some of the unique factors associated with cultural policies in Great Britain from the end of World War II until the present day. To this end, I will review the two main trends in political thought with respect to the role of culture in public well-being: cultural democracy or the democratisation of culture in its diverse aspects. I will address the crucial role of Cultural Studies in shaping the debate and will explore some of its principal ideas today. I will also summarise the function of some of the organisations responsible for cultural management and comment on the singular nature of their organisation. In addition, I will examine the central role played by the large metropolitan corporations in ensuring the continuity of access policies and in defining the new hegemonic discourses of the 21st century. Special attention will be paid to particular actors (generally male, with two notable exceptions) and to changes in cultural policies under the Wilson/Blair Labour governments and Thatcher’s Conservative government, noting the arrival ‒to stay‒ of the discourse of the creative industries and describing the current panorama of cultural debate in the country. As with the first part, the present article excludes numerous matters that are too complex to address in the limited space available (for example, the different policies of Scotland, Wales and Northern Ireland)

VICARED: A Neural Network Based System for the Detection of Electrical Disturbances in Real Time

The study of the quality of electric power lines is usually known as Power Quality. Power quality problems are increasingly due to a proliferation of equipment that is sensitive and polluting at the same time. The detection and classification of the different disturbances which cause power quality problems is a difficult task which requires a high level of engineering knowledge. Thus, neural networks are usually a good choice for the detection and classification of these disturbances. This paper describes a powerful system for detection of electrical disturbances by means of neural networks

Reconocimiento de parásitos de leishmania en imágenes de microscopio

Leishmania es un género de protistas responsables de la enfermedad conocida como leishmaniasis o leishmaniosis. El principal vector de infección son los mosquitos de los géneros Phlebotomus (en Eurasia y África) y Lutzomyia (en América). La leishmaniasis afecta a varios grupos de vertebrados, entre ellos, marsupiales, cánidos, roedores y primates, y se estima que afecta actualmente a 6 millones de personas en 98 países. Cada año se producen entre 0,9 y 1,6 millones de nuevos casos, y se conocen 21 especies que causan enfermedades en los seres humanos. En el presente trabajo se propone un sistema de detección de una serie de características de estos organismos, como su cantidad, posición en la imagen y tamaño mediante técnicas de visión por computador. Las imágenes a tratar son tomadas mediante el uso de un microscopio óptico, en condiciones de aumento y luminosidad variables pero registradas en el nombre del fichero contenedor de la imagen. Las imágenes de laboratorios son analizadas con éxito por el software, ya que los parásitos son detectados y medidos, las imágenes son marcadas para que las caracteristicas relevantes puedan ser discernidas a primera vista y se genera un documento con datos relevantes al análisis.Leishmania is a genus of protists responsible for the disease known as leishmaniasis or leishmaniasis. The main vector of infection is mosquitoes of the genera Phlebotomus (in Eurasia and Africa) and Lutzomyia (in the Americas). Leishmaniasis affects several vertebrate groups, including marsupials, canids, rodents and primates, and is currently estimated to affect 6 million people in 98 countries. Between 0.9 and 1.6 million new cases occur each year, and 21 species are known to cause disease in humans. This work proposes a system for detecting a series of characteristics of these organisms, such as their number, position in the image and size, by means of computer vision techniques. The images to be processed are taken using an optical microscope, under variable magnification and luminosity conditions, but registered in the name of the file containing the image. The laboratory images are successfully analyzed by the software, as the parasites are detected and measured, the images are marked so that the relevant features can be discerned at first glance and a document with data relevant to the analysis is generated

Why ‘arm’s length’? Examining the origins of Anglosaxon cultural policies.

Este artículo intenta profundizar en el concepto de arm´s lenght o principio de independencia de las instituciones artísticas frente a los Gobiernos que rige las políticas culturales en el mundo anglosajón. Para ello, se insiste en el estudio del origen reciente de su historia, muy especialmente ligada al nacimiento del capitalismo financiero de comienzos del siglo XX en los Estados Unidos.This article aims to develop the concept of arm´s length or the principle of independence of artistic institutions from governments who govern cultural policies in the Anglo-Saxon world. To do this, emphasis is placed on the study of the recent birth of its history, and its particular link to the birth of financial capitalism at the start of the 20th century in the United States

Variation operators for semigroups associated with Fourier-Bessel expansions

In this paper we establish $L^p$-boundedness properties for variation operators defined by semigroups associated with Fourier-Bessel expansions