La participación ciudadana a la gobernanza urbana: las transformaciones políticas y territoriales

El eje central de esta comunicación es la relación de la participación ciudadana y la gobernanza urbana con el modelo de desarrollo y su componente territorial. Las transformaciones de los últimos años han reconfigurado las relaciones políticas, sociales y económicas. En ese proceso se ha impuesto una nueva gobernanza de orden global y la participación ha quedado cada vez más alejada de los centros de decisión, lo que ha supuesto la concentración de poder en unas pocas manos y la desconfianza en las instituciones, derivada de la complejidad administrativa y la falta de transparencia en la toma de decisiones. La construcción del espacio requiere de participación ciudadana y una gobernanza urbana que busque la acción pública enfocada en las necesidades reales de la sociedad ? y no en los intereses económicos de élites? y que desarrolle el sentido de responsabilidad colectivo ante el entorno. La vinculación (y comprensión) de los procesos de toma de decisiones a diferentes escalas (multi-level-governance) y la puesta en valor de la escala local para las cuestiones espaciales son claves necesarias para una gobernanza urbana que incorpore la acción social como fuerza transformadora de los modelos de desarrollo y su componente territorial.

Realistic detailed balance study of the quantum efficiency of quantum dot solar cells

An attractive but challenging technology for high efficiency solar energy conversion is the intermediate band solar cell (IBSC), whose theoretical efficiency limit is 63%, yet which has so far failed to yield high efficiencies in practice. The most advanced IBSC technology is that based on quantum dots (QDs): the QD-IBSC. In this paper, k·p calculations of photon absorption in the QDs are combined with a multi-level detailed balance model. The model has been used to reproduce the measured quantum efficiency of a real QD-IBSC and its temperature dependence. This allows the analysis of individual sub-bandgap transition currents, which has as yet not been possible experimentally, yielding a deeper understanding of the failure of current QD-IBSCs. Based on the agreement with experimental data, the model is believed to be realistic enough to evaluate future QD-IBSC proposals.

Digital Coherent Receivers and Advanced Optical Modulation Formats in 100 and 200 Gb/s DWDM Systems

Recent advances in coherent optical receivers is reviewed. Digital-Signal-Processing (DSP) based phase and polarization management techniques make coherent detection robust and feasible. With coherent detection, the complex field of the received optical signal is fully recovered, allowing compensation of linear and nonlinear optical impairments including chromatic dispersion (CD) and polarization-mode dispersion (PMD) using digital filters. Coherent detection and advanced optical modulation formats have become a key ingredient to the design of modern dense wavelength-division multiplexed (DWDM) optical broadband networks. In this paper, firstly we present the different subsystems of a digital coherent optical receiver, and secondly, we will compare the performance of some multi-level and multi-dimensional modulation formats in some physical impairments and in high spectral-efficiency (SE) and high-capacity DWDM transmissions, simulating the DSP with Matlab and the optical network performance with OptiSystem software.

Associations between macronutrient intake and serum lipid profile depend on body fat in European adolescents: the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) study

The present study aimed to investigate the relationships between macronutrient intake and serum lipid profile in adolescents from eight European cities participating in the HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) cross-sectional study (2006–7), and to assess the role of body fat-related variables in these associations. Weight, height, waist circumference, skinfold thicknesses, total choles- terol, HDL-cholesterol (HDL-C), LDL-cholesterol, TAG, apoB and apoA1 were measured in 454 adolescents (44 % boys) aged 12·5–17·5 years. Macronutrient intake (g/4180 kJ per d (1000 kcal per d)) was assessed using two non-consecutive 24 h dietary recalls. Associations were evaluated by multi-level analysis and adjusted for sex, age, maternal education, centre, sum of four skinfolds, moderate-to-vigorous.