Identifying the preferred subset of enzymatic profiles in nonlinear kinetic metabolic models via multiobjective global optimization and pareto filters

Optimization models in metabolic engineering and systems biology focus typically on optimizing a unique criterion, usually the synthesis rate of a metabolite of interest or the rate of growth. Connectivity and non-linear regulatory effects, however, make it necessary to consider multiple objectives in order to identify useful strategies that balance out different metabolic issues. This is a fundamental aspect, as optimization of maximum yield in a given condition may involve unrealistic values in other key processes. Due to the difficulties associated with detailed non-linear models, analysis using stoichiometric descriptions and linear optimization methods have become rather popular in systems biology. However, despite being useful, these approaches fail in capturing the intrinsic nonlinear nature of the underlying metabolic systems and the regulatory signals involved. Targeting more complex biological systems requires the application of global optimization methods to non-linear representations. In this work we address the multi-objective global optimization of metabolic networks that are described by a special class of models based on the power-law formalism: the generalized mass action (GMA) representation. Our goal is to develop global optimization methods capable of efficiently dealing with several biological criteria simultaneously. In order to overcome the numerical difficulties of dealing with multiple criteria in the optimization, we propose a heuristic approach based on the epsilon constraint method that reduces the computational burden of generating a set of Pareto optimal alternatives, each achieving a unique combination of objectives values. To facilitate the post-optimal analysis of these solutions and narrow down their number prior to being tested in the laboratory, we explore the use of Pareto filters that identify the preferred subset of enzymatic profiles. We demonstrate the usefulness of our approach by means of a case study that optimizes the ethanol production in the fermentation of Saccharomyces cerevisiae.

Condicionants sociològics de la planificació lingüística en un context global i multicultural

La complexitat de la conformació de les societats actuals provoca l’aparició de reptes nous que s’afegeixen a l’emergència de realitats ja existents i no resoltes. Això fa que s’hagin d’analitzar amb mirada i perspectives noves problemes, qüestions i polítiques que es creien resolts o, com a mínim, superats. Obliga, alhora, a repensar les estratègies i també a repensarnos com a societat. La política lingüística, i la planificació que n’és la resultant, no pot quedar al marge d’aquestes reflexions perquè actua en —i per a— una població i en —i per a— una societat determinada, i l’una i l’altra estan en plena transformació i canvi. Els diversos contextos socials actuals en els quals —i per als quals— es prenen les decisions lingüístiques contenen condicionants característics que s’afegeixen i interactuen amb els preexistents. Uns i altres, amb diferents graus d’intensitat, les influencien. Aquest article s’aproxima a alguns d’aquests elements i a aquest context divers, global i local que els dota d’especificitat.

Local effects and global impact in neurotoxicity and neurodegeneration: The Xi"an International Neurotoxicology Conference

'Neurotoxicity and Neurodegeneration: Local Effect and Global Impact' was the theme of the Xi"an International Neurotoxicology Conference (XINC), held in Xi"an, June 2011. The Conference was a joint event of the 13th Biennial Meeting of the International Neurotoxicology Association (INA-13) and the 11th International Symposium on Neurobehavioral Methods and Effects in Occupational and Environmental Health (NEUREOH-11) of the Scientific Committee on Neurotoxicology and...

Potential of local bio-geoengineering to mitigate dangerous temperature increases in a global warming scenario

Crops and forests are already responding to rising atmospheric carbon dioxide and air temperatures. Increasing atmospheric CO2 concentrations are expected to enhance plant photosynthesis. Nevertheless, after long-term exposure, plants acclimate and show a reduction in photosynthetic activity (i.e. down-regulation). If in the future the Earth"s temperature is allowed to rise further, plant ecosystems and food security will both face significant threats. The scientific community has recognized that an increase in global temperatures should remain below 2°C in order to combat climate change. All this evidence suggests that, in parallel with reductions in CO2 emissions, a more direct approach to mitigate global warming should be considered. We propose here that global warming could be partially mitigated directly through local bio-geoengineering approaches. For example, this could be done through the management of solar radiation at surface level, i.e. by increasing global albedo. Such an effect has been documented in the south-eastern part of Spain, where a significant surface air temperature trend of -0.3°C per decade has been observed due to a dramatic expansion of greenhouse horticulture.

El resultado global: una aproximación de la información contable a la realidad de los mercados

Un elemento novedoso que incorporan las cuentas anuales es el resultado global, como nuevo concepto de resultado (que incorpora el tradicional resultado neto más o menos los ajustes en patrimonio neto) en sintonía con la realidad de los mercados. En nuestro trabajo analizamos si la información derivada del resultado global, en el período 2009-2011 para las empresas del IBEX 35, añade más poder informativo al análisis de los estados financieros y en especial a las rentabilidades como indicadores de la realidad de los mercados.

El fútbol y el negocio del entretenimiento global. Los clubes como multinacionales del ocio

El artículo tiene como objetivo analizar el proceso de expansión internacional de los clubes más ricos del fútbol español durante la primera década del siglo XXI, Real Madrid y FC Barcelona. Después de que los clubes de la Premier League inglesa fueran los primeros en crear una estrategia de branding internacional, otras ligas y organizaciones deportivas han adoptado sus mismos sistemas de gestión empresarial. En España, el Real Madrid y el FC Barcelona son el ejemplo más evidente, por su número de fans en todo el mundo, por sus acuerdos internacionales en la comercialización de sus productos con otras organizaciones y por la presencia que tienen sus marcas en todo el mundo gracias a las inversiones de sus fundaciones en escuelas de fútbol en concepto de Responsabilidad Social Corporativa. Por eso, ambos clubes, Real Madrid y FC Barcelona, pueden calificarse de nuevas multinacionales del ocio.

Being Global? La crisis y los museos virtuales en arte público y diseño urbano

Este trabajo surge de la experiencia desarrollada en Barcelona, Zaragoza y Lisboa de puesta en marcha de los respectivos sistemas de información del Arte Público de estas ciudades, así como del desarrollo de investigación posibilitado por los proyectos BHA2002- 00520;HUM2005-00420;HUM2006-12803-C02-01, HAR 2009-13989-C02-01, del Ministerior de Ciencia e Innvoción español y de los proyectos 2005SGR00150 y 2009SGR903 de la Generalitat de Catalunya, así como de los distintos convenios entre la Universidad y el Ayuntamiento de Barcelona. Sorprendentemente, en el panorama de la innovación internacional, son proyectos del sur de Europa los que plantean por primera vez un uso sistemático de Internet para el mejor conocimiento y difusión de esta parte del patrimonio que es el Arte Público de las ciudades, una historia escrita en bronce y piedra que forma parte de la herencia cultural, de las raíces identitarias y del orgullo de ciudad Sin embargo, la crisis internacional supone un frenazo importante a estos proyectos y a la posibilidad de desarrollar un Museo Virtual del Arte Público y el Diseño Urbano.

Calidad de vida global en personas con demencia

Objetivo: Evaluar la calidad de vida (CV) global en personas con demencia e investigar las variables asociadas con la percepción subjetiva de la CV. Pacientes y métodos: Se llevó a cabo un estudio transversal en seis centros de Barcelona y Tarragona. Un total de 99 personas con demencia leve-moderada que vivían en casa con un cuidador conocido completaron una entrevista cara-cara que incluía información sociodemográfica, percepción del estado de salud, un listado de problemas crónicos de salud, sintomatología depresiva, estado funcional, aspectos positivos, sentido de la vida y satisfacción con las relaciones personales. La CV global se evaluó con la pregunta global del World Health Organization Quality of Life-BREF. Resultados: El 40,6% de los entrevistados consideró su CV como buena/muy buena. Los análisis univariados de regresión logística ordinal y binaria no mostraron asociación entre CV con datos sociodemográficos, gravedad de la demencia ni estado funcional, pero sí con las otras variables de estudio. Los análisis multivariados de la regresión logística ordinal y binaria mostraron que una mejor percepción de salud y mayor satisfacción con las relaciones personales se asociaban con mejor CV. Asimismo, en el análisis multivariado de regresión logística ordinal, mejor CV se asoció con un menor número de síntomas depresivos, y en el análisis de regresión logística binaria, con disfrutar de la vida y menor gravedad de la demencia. Conclusiones: Personas con demencia leve-moderada pueden informar sobre su CV y estados subjetivos. Además de los aspectos relacionados con la salud, aspectos positivos y las relaciones personales deberían evaluarse sistemáticamente en esta población.

Regulation of Port Charges in Spain: Global versus Local Competition

This article examines the determinants of traffic volumes and the revenues per tonne generated by Spain’s port authorities. The interest of the study lies on the strong differences between port authorities in a context of strict regulation but that provides some scope for price competition. We find that port charges influence the amount of traffic that a port is able to generate. Furthermore, we find clear evidence of local price competition and report mixed results for global competition. Revenues per tonne are higher in ports operating more international regular lines and with multinational terminal operators, while they are lower in ports with nearby competing facilities and where the market share of the dominant shipping firm is high.

Braving the Storm: How Are Global Biofuel Policies Sustained Despite Being Contested? An Analysis of the Biofuel Discourses of the EU, Brazil and Mozambique

Considered as a remedy to multiple problems that our world is facing, biofuels are nowadays promoted on a global scale. Despite this globalised approach, however, biofuels are heavily contested. Not only the social implications of biofuels are disputed and uncertain, particularly in countries of the global South, but also their environmental and economic rationales. Given these huge controversies, policies promoting biofuels would seem difficult to maintain. Yet, support for them has been surprisingly well established on the political agendas. With the aim of understanding this puzzle, this study asks how the dominant approach to biofuels has been sustained on a global level. In order to answer this question, the meanings and assumptions in biofuel discourses are explored through the lens of Maarten Hajer’s “argumentative” discourse analysis. Based on the existence of a “partnership for sustainable bioenergy” between the EU, Brazil and Mozambique, the study takes these three locations as case studies. The analysis reveals that various discursive strategies, including a particular problem construction and the use of two main story-lines, have played an important role in ensuring the permanence of the global approach to biofuels. Moreover, while the discourse of critics against biofuels demonstrates that there is room for contestation, the analysis finds that the opponents’ discourse largely fails to target the most salient justification for biofuels. A more effective strategy for critics would therefore be to also question the problem constructions underpinning this main justification in the global discourse.

Absence of flash-lag when judging global shape from local positions

When a flash is presented aligned with a moving stimulus, the former is perceived to lag behind the latter (the flash-lag effect). We study whether this mislocalization occurs when a positional judgment is not required, but a veridical spatial relationship between moving and flashed stimuli is needed to perceive a global shape. To do this, we used Glass patterns that are formed by pairs of correlated dots. One dot of each pair was presented moving and, at a given moment, the other dot of each pair was flashed in order to build the Glass pattern. If a flash-lag effect occurs between each pair of dots, we expect the best perception of the global shape to occur when the flashed dots are presented before the moving dots arrive at the position that physically builds the Glass pattern. Contrary to this, we found that the best detection of Glass patterns occurred for the situation of physical alignment. This result is not consistent with a low-level contribution to the flash-lag effect.

La competència intercultural com a recurs per a contemplar una dimensió global i inclusiva del col·lectiu amazic. En relació amb les competències bàsiques i l'àrea d'educació física de primària

Des que es va iniciar el segle, i a causa dels grans fluxos migratoris de procedències diverses, la població de Catalunya s’ha incrementat en més d’1 milió d’habitants. Diferents actors socials reivindiquen que un dels reptes presents en la societat catalana és reduir les diferències i en alguns casos les desigualtats que es detecten entre la població autòctona i la població d’origen estranger. Amb tot això, diversos autors afirmen que l’espai d’Educació Física de Primària és un espai òptim per atendre a la diversitat cultural, promoure els valors humans, la no discriminació entre l'alumnat i la cohesió i inclusió social. Amb tot aquest marc, apareix el professorat d’Educació Física de Primària i la competència intercultural com a agents de canvi per tal de promocionar la inclusió social en les seves sessions i de retruc en societat. En aquest Treball de Fi de Grau, s’intentarà analitzar i aportar solucions sobre algunes de les qüestions que afecten tant als Mestres d’Educació Física de Primària com a la competència intercultural a l’hora de promocionar la inclusió social del col•lectiu Marroquí, ja que aquest és més nombrós de població estrangera empadronada a Catalunya.

The whereabouts of an ancient wonderer: Global phylogeography of the solitary ascidian Styela plicata

Genetic tools have greatly aided in tracing the sources and colonization history of introduced species. However, recurrent introductions and repeated shuffling of populations may have blurred some of the genetic signals left by ancient introductions. Styela plicata is a solitary ascidian distributed worldwide. Although its origin remains unclear, this species is believed to have spread worldwide by travelling on ship's hulls. The goals of this study were to infer the genetic structure and global phylogeography of S. plicata and to look for present-day and historical genetic patterns. Two genetic markers were used: a fragment of the mitochondrial gene Cytochrome Oxidase subunit I (COI) and a fragment of the nuclear gene Adenine Nucleotide Transporter/ADP-ATP Translocase (ANT). A total of 368 individuals for COI and 315 for ANT were sequenced from 17 locations worldwide. The levels of gene diversity were moderate for COI to high for ANT. The Mediterranean populations showed the least diversity and allelic richness for both markers, while the Indian, Atlantic and Pacific Oceans had the highest gene and nucleotide diversities. Network and phylogenetic analyses with COI and ANT revealed two groups of alleles separated by 15 and 4 mutational steps, respectively. The existence of different lineages suggested an ancient population split. However, the geographic distributions of these groups did not show any consistent pattern, indicating different phylogeographic histories for each gene. Genetic divergence was significant for many population-pairs irrespective of the geographic distance among them. Stochastic introduction events are reflected in the uneven distribution of COI and ANT allele frequencies and groups among many populations. Our results confirmed that S. plicata has been present in all studied oceans for a long time, and that recurrent colonization events and occasional shuffling among populations have determined the actual genetic structure of this species.

La societat civil global: les complexitats d’un espai de contestació

Societat civil global és un concepte contestat utilitzat des de diferents aproximacions per a descriure una realitat global. El working paper assenyala la utilitat d’una aproximació de societat civil global per analitzar les potencialitats de l’esfera d’abordar els reptes globals del món d’avui. D’acord amb aquesta aproximació la societat civil global és una àrea global complexa de conflicte i contestació, una àrea que ofereix un lloc i uns valors per a reconsiderar el món de diferents maneres, incloent les visions dels marginats de la societat civil. Per una millor comprensió del concepte i dels debats actuals, el paper repassa les concepcions històriques de societat civil des de la Il·lustració fins avui i el context en el qual el concepte adquireix un nou significat i incorpora l’aspecte global. El paper és la fase inicial d’una futura recerca sobre les potencialitats de la societat civil global per a influir i modelar l’estructura del sistema internacional.

Identifying strategies for mitigating the global warming impact of the EU-25 economy using a multi-objective input-output approach

Global warming mitigation has recently become a priority worldwide. A large body of literature dealing with energy related problems has focused on reducing greenhouse gases emissions at an engineering scale. In contrast, the minimization of climate change at a wider macroeconomic level has so far received much less attention. We investigate here the issue of how to mitigate global warming by performing changes in an economy. To this end, we make use of a systematic tool that combines three methods: linear programming, environmentally extended input output models, and life cycle assessment principles. The problem of identifying key economic sectors that contribute significantly to global warming is posed in mathematical terms as a bi criteria linear program that seeks to optimize simultaneously the total economic output and the total life cycle CO2 emissions. We have applied this approach to the European Union economy, finding that significant reductions in global warming potential can be attained by regulating specific economic sectors. Our tool is intended to aid policymakers in the design of more effective public policies for achieving the environmental and economic targets sought.