Effective Theories for 2+1 Dimensional Non-Abelian Topological Spin Liquids

In this work we propose an effective low-energy theory for a large class of 2+1 dimensional non-Abelian topological spin liquids whose edge states are conformal degrees of freedom with central charges corresponding to the coset structure $su(2)_k\oplus su(2)_{k'}/su(2)_{k+k'}$. For particular values of $k'$ it furnishes the series for unitary minimal and superconformal models. These gapped phases were recently suggested to be obtained from an array of one-dimensional coupled quantum wires. In doing so we provide an explicit relationship between two distinct approaches: quantum wires and Chern-Simons bulk theory. We firstly make a direct connection between the interacting quantum wires and the corresponding conformal field theory at the edges, which turns out to be given in terms of chiral gauged WZW models. Relying on the bulk-edge correspondence we are able to construct the underlying non-Abelian Chern-Simons effective field theory.Comment: 41 pages, 5 figures, typos corrected, references added, published versio

Experimental demonstration of digital predistortion for orthogonal frequency-division multiplexing-radio over fibre links near laser resonance

Radio over fibre (RoF), an enabling technology for distribution of wireless broadband service signals through analogue optical links, suffers from non-linear distortion. Digital predistortion has been demonstrated as an effective approach to overcome the RoF non-linearity. However, questions remain as to how the approach performs close to laser resonance, a region of significant dynamic non-linearity, and how resilient the approach is to changes in input signal and link operating conditions. In this work, the performance of a digital predistortion approach is studied for directly modulated orthogonal frequency-division multiplexing RoF links operating from 2.47 to 3.7 GHz. It extends previous works to higher frequencies, and to higher quadrature amplitude modulation (QAM) levels. In addition, the resilience of the predistortion approach to changes in modulation level of QAM schemes, and average power levels are investigated, and a novel predistortion training approach is proposed and demonstrated. Both memoryless and memory polynomial predistorter models, and a simple off-line least-squares-based identification method, are used, with excellent performance improvements demonstrated up to 3.0 GHz

Estudo do efeito magnetoconvectivo e a sua ação sobre a deposição de cobre.

Entrada padronizada: COLNAGO, L. A

The Chico Mendes Extractive Reserve: trajectories of agro-extractive development in Amazonia

The Chico Mendes Extractive Reserve (CMER) located in Acre, Brazil in the southwest Amazon is a powerful symbol of the rubber tapper social movement. Created in 1990, the Reserve is named after rubber tapper and union leader Francisco “Chico” Mendes, who was assassinated by ranchers in 1988. The concept of the extractive reserve, a type of sustainable-use protected area, was conceived by rubber tappers to secure land rights and to protect the forests from which they derived their livelihoods. Thirty years since its creation, non-timber forest product (NTFP) extraction maintains a critical role in CMER resident livelihoods, but it is now one of multiple and dynamic trajectories of income generating activities in the CMER. The state government has promoted sustainable development policies aimed at productive and multiple use of forests, including community-based timber management (CBTM). Concomitantly, the scale and scope of small-scale cattle ranching reflecting a growing “cowboy culture” pervasive in Eastern Acre is growing. These forces have brought sociocultural changes to the reserve as CMER residents engage these intertwined trajectories to improve their livelihoods. This article explores the trajectories of multiple development strategies in the CMER. We do this by revisiting and expanding on the principal themes of research of the co-authors – NTFP extraction, cattle ranching, and CBTM.  Increasingly diverse CMER households demand multiple pathways to improve livelihoods, and these trajectories have created new economic opportunities for reserve residents. Although the NTFP sector has experienced some success in market development and valued-added initiatives, investments have not produced a sustainable and diversified extractive sector. Cattle ranching and CBTM have provided economic benefits to reserve residents’ livelihoods, but they have also created internal tensions across the social movement and governments agencies. A strategic vision is required that brings diverse government, non-government and reserve residents together and articulates how these dynamic, linked, and sometimes conflicting trajectories can synergize within a balanced, diversified livelihood framework to ensure long-term sustainability of the CMER

Price-setting hotel competition with corporate social responsibility

Pricing plays an important role in any market competition, but particularly in those businesses that hold a seat in hyper competitive economic activities such as hotels. This paper analyses a market competition between one corporate social responsibility (CSR) hotel and one for profit (FP) hotel, in which both hotels set room prices. We study three different market behaviors: (i) both hotels take their decisions simultaneously; (ii) the CSR hotel takes the leader position; (iii) the FP hotel takes the leader position. For each situation, by using game theory techniques, we compute the different outcomes of the model at equilibrium. We also describe the effects of CSR on the outcomes.info:eu-repo/semantics/publishedVersio

Inventario de Amphipoda (Peracarida: Senticaudata y Amphilochidea) del Río Miño Internacional, Península Ibérica

Crustacea are a diverse and abundant group of the littoral and estuarine community invertebrate fauna. This study presents the first survey on the Amphipod fauna found at the Minho River estuary, Iberian Peninsula, collected through glass eel fishing bycatch, grab sampler and beam trawl sampling methods. A total of 100 specimens were examined belonging to 18 families, 23 genera and 34 species (23 new records for the Minho River, including one new record for Portugal, Parametopa kervillei Chevreux, 1901). The most represented families were Ampeliscidae, with 7 species from the genus Ampelisca, and Gammaridae, with 3 species from 3 distinct genera. Brief diagnosis, ecological notes, species distributions and figures are provided aiming to provide taxonomic support on future environmental projects on this area.Los crustáceos son un grupo diverso y abundante de la fauna invertebrada de la comunidad litoral y estuarina. Este estudio presenta el primer compendio sobre la fauna de anfípodos en el estuario del río Miño, Península Ibérica, recolectada a través de captura accidental de pesca de angula, y muestreos con draga y arrastre de vara. Se examinaron un total de 100 especímenes pertenecientes a 18 familias, 23 géneros y 34 especies (23 nuevos registros para el río Miño, incluyendo un nuevo registro para Portugal, Parametopa kervillei Chevreux, 1901). Las famílias más representadas fueron Ampeliscidae, con 7 especies del género Ampelisca, y Gammaridae, con 3 especies de géneros distintos. Además se proporciona para todas las espécies un breve diagnóstico, notas ecológicas, distribución y figuras con el objetivo de proporcionar apoyo taxonómico en futuros proyectos medioambientales en esta zona

Evaluación de la calidad ecológica del estuario del Miño (Peninsula Iberica Noroeste) basada en la concentración de metales en sedimentos y en Corbicula fluminea

The concentrations of metals (Cd, Cr, Cu, Fe, Ni, Pb and Zn) in sediments and the soft tissues of Corbicula fluminea from the Minho estuary (Northwest Iberian Peninsula) were determined to assess the spatial variation of metal bioavailability and to classify the ecological quality of the estuary. Metal concentrations in sediments showed significant spatial variation ( p < 0.0003) and ranged in concentration (dry weight basis) from 0.025-0.36 mg Cd/kg, 7-16 mg Cr/kg, 2.7-24.6 mg Cu/kg, 7.3-45 mg Ni/kg, 4.1-15 mg Pb/kg and 37.3-110 mg Zn/kg. According to the Norwegian Pollution Control Authority metal concentration guidelines for sediments, this first ecological quality classification of the Minho estuary is “Class I/II-Background/Good.” Metal concentrations in the soft tissues of C. fluminea also showed significant spatial variation ( p < 0.0001) and ranged in concentration (dry weight basis) from 1.1-2.5 mg Cd/kg, 1.0-1.8 mg Cr/kg, 34-71 mg Cu/kg, 5.8-11 mg Ni/kg, 0.45-1.3 mg Pb/kg and 136-161 mg Zn/kg. The high Cu concentrations bioaccumulated by C. fluminea in the Minho estuary suggest that the estuary should be classified as “Class II/III-Moderately/Remarkably Polluted.” Thus, the primary contributions of this work are that C. fluminea proved to be a good and adequate biomonitor of metal contamination in the Minho estuary and that it could be used to assess the ecological quality of estuarine ecosystems worldwide.La concentración de metales (Cd, Cr, Cu, Fe, Ni, Pb and Zn) en sedimentos y tejidos blandos de Corbicula fluminea procedentes del estuario del Minho (Noroeste Península Ibérica) fue determinada para evaluar variaciones espaciales en la biodisponibilidad de los metales y para comparar diferentes clasificaciones ecológicas de calidad. Los sedimentos retuvieron metales en rangos (peso seco) entre 0.025-0.36 mg Cd/kg, 7-16 mg Cr/kg, 2.7-24.6 mg Cu/kg, 7.3-45 mg Ni/kg, 4.1-15 mg Pb/kg y 37.3-110 mg Zn/kg, lo que revela una variación espacial significativa (p < 0.0003). Las directrices sobre concentración de metales en sedimentos recomendadas por la Norwegian Pollution Control Authority permitieron obtener una primera clasificación de calidad ecológica del estuario del Miño designada como “Clase I/II-Basal/Buena”. En los tejidos blandos de C. fluminea también se encontraron variaciones espaciales significativas, (p < 0.0001) y sus concentraciones variaron (peso seco) entre 1.1-2.5 mg Cd/kg, 1.0-1.8 mg Cr/kg; 34-71 mg Cu/kg, 5.8-11 mg Ni/kg, 0.45-1.3 mg Pb/kg y 136- 161 mg Zn/kg. Sin embargo, teniendo en cuenta las altas concentraciones de Cu bioacumuladas por C. fluminea el estuario del Miño debería estar clasificado como “Clase II/III-Moderadamente/Notablemente contaminado”. Así, la principal conclusión de este trabajo, es que C. fluminea ha demostrado ser un adecuado indicador de la contaminación en el estuario del Miño y podría ser utilizada para evaluar la calidad ecológica de los ecosistemas estuarinos a nivel mundial