Effects of wildfires on environmental variability: a comparative analysis using different spectral indices, patch metrics and thematic resolutions

P. 697-710Knowledge on environmental variability and how it is affected by disturbances is crucial for understanding patterns of biodiversity and determining adequate conservation strategies. The aim of this study is to assess environmental variability in patches undergoing post-fire vegetation recovery, identifying trends of change and their relevant drivers. We particularly evaluate: the value of three spectral indices derived from Landsat satellite data [Normalized Burn Ratio (NBR), Normalized Difference Vegetation Index (NDVI) and Wetness Component of the Tasseled Cap Transformation (TCW)] for describing secondary succession; the effectiveness of three metrics (diversity, evenness and richness) as indicators of patch variability; and how thematic resolution can affect the perception of environmental variability patterns. While the system was previously characterised as highly resilient from estimations of vegetation cover, here we noted that more time is required to fully recover pre-fire environmental variability. Using mean diversity as indicator of patch variability, we found similar patterns of temporal change for the three spectral indices (NBR, NDVI and TCW). Analogous conclusions could be drawn for richness and evenness. Patch variability, measured as diversity, showed consistent patterns across thematic resolutions, although values increased with the number of spectral classes. However, when the variance of diversity was plotted against thematic resolution, different scale dependencies were detected for those three spectral indices, yielding a dissimilar perception of patch variability. In general terms, NDVI was the best performing spectral index to assess patterns of vegetation recovery, while TCW was the worst. Finally, burned patches were classified into three classes with similar trends of change in environmental variability, which were strongly related to fire severity, elevation and vegetation type.S

On the Integration of Grassmannian Constellations into LTE Networks: a Link-level Performance Study

This paper presents Grassmannian signaling as a transmission scheme that can be integrated in Long Term Evolution (LTE) to support higher user speeds and to increase the throughput achievable in the high Signal to Noise Ratio (SNR) regime. This signaling is compared, under realistic channel assumptions, with the diversity transmission modes standardized in LTE, in particular, Space-Frequency Block Coding and Frequency-Switched Transmit Diversity for two and four transmit antennas, respectively. In high-speed scenarios, and even with high antenna correlation, Grassmannian signaling outperforms the LTE diversity transmission modes starting from four transmit antennas. Furthermore, in the high SNR regime, Grassmannian signaling can increase the link data rate up to 10% and 15% for two and four antennas, respectively

Maximal Factorization of Operators Acting in Kothe-Bochner Spaces

[EN] Using some representation results for Kothe-Bochner spaces of vector valued functions by means of vector measures, we analyze the maximal extension for some classes of linear operators acting in these spaces. A factorization result is provided, and a specific representation of the biggest vector valued function space to which the operator can be extended is given. Thus, we present a generalization of the optimal domain theorem for some types of operators on Banach function spaces involving domination inequalities and compactness. In particular, we show that an operator acting in Bochner spaces of p-integrable functions for any 1First author is supported by Grant MTM2011-23164 of the Ministerio de Economia y Competitividad (Spain). Second author is supported by Grant 284110 of CONACyT (Mexico). Fourth author is supported by Grant MTM2016-77054-C2-1-P of the Ministerio de Ciencia, Innovacion y Universidades, Agencia Estatal de Investigaciones (Spain) and FEDER.Calabuig, JM.; Fernández-Unzueta, M.; Galaz-Fontes, F.; Sánchez Pérez, EA. (2021). Maximal Factorization of Operators Acting in Kothe-Bochner Spaces. Journal of Geometric Analysis. 31(1):560-578. https://doi.org/10.1007/s12220-019-00290-4S56057831

Converting sporting capacity to entrepreneurial capacity: A process perspective

Managing a personal sporting career and conducting an entrepreneurial initiative are two vitally connected processes. Most athletes require a second career and many engage in entrepreneurship. Research on the similarities and differences of the sports career management process and entrepreneurial process with a special emphasis on the necessary capacities will have a ready audience among practitioners. This study begins the task of closing a surprising gap. In entrepreneurship literature, there is (1) growing research on entrepreneurial process and entrepreneurial capacity as the key driver; (2) strong work in generic, descriptive and explanatory modelling of process as a whole and capacity as a sub-process; and (3) the presence of a generic model of entrepreneurial process based of what distinguishes entrepreneurial capacity from other human capacities. In sports management literature, these research strands are virtually absent. The study indicates how the deficiency might be remedied

Lung tumorspheres as a drug screening platform against cancer stem cells

Treatment resistance and metastasis are linked to cancer stem cells (CSCs). This population represents a promising target, but remains unexplored in lung cancer. The main objective of this study was to characterize lung CSCs and discover new therapeutic strategies

Map-Based Channel Model for Urban Macrocell Propagation Scenarios

The evolution of LTE towards 5G has started and different research projects and institutions are in the process of verifying new technology components through simulations. Coordination between groups is strongly recommended and, in this sense, a common definition of test cases and simulation models is needed. The scope of this paper is to present a realistic channel model for urban macrocell scenarios. This model is map-based and takes into account the layout of buildings situated in the area under study. A detailed description of the model is given together with a comparison with other widely used channel models. The benchmark includes a measurement campaign in which the proposed model is shown to be much closer to the actual behavior of a cellular system. Particular attention is given to the outdoor component of the model, since it is here where the proposed approach is showing main difference with other previous models

Time-Frequency Coupled Proportional Fair Scheduler with Multicarrier Awareness for LTE Downlink

Abstract-Proportional fair schedulers have been thoroughly used in Long Term Evolution (LTE) due to their ability to provide a good trade-off between cell spectral efficiency and user fairness. Current algorithms provide suboptimum solutions at a low computational cost, but present several drawbacks. This paper proposes a Coupled and Multicarrier Aware PFS (CMA-PFS) for LTE downlink that increases efficiency as compared with current algorithms with independent time and frequency domain scheduling, referred to as Decoupled PFS (D-PFS). The proposed algorithm includes new features such as tight coupling between time and frequency domain scheduling and multicarrier transmission awareness. Simulations have been conducted using an International Mobile Telecommunications Advanced (IMT-Advanced) compliant semi-static simulator. Results show that the CMA-PFS improves proportional fairness as compared with D-PFS that is reflected both in an increase of cell spectral efficiency (around +2%) and a higher cell-edge user spectral efficiency (around +10%) in a Single User MIMO (SU-MIMO) system

Estudio comparativo de los regímenes de fuego en tres espacios naturales del oeste peninsular mediante imágenes Landsat

P. 77-86La cartografía de zonas quemadas es una herramienta útil para la caracterización del régimen de fuegos. Mediante imágenes de los sensores Landsat TM y ETM+ se ha generado la cartografía de fuegos de tres espacios naturales de Castilla y León para el período 1992-2002, caracterizándose posteriormente el patrón temporal del régimen de fuegos de cada zona. Se analizaron además diversas metodologías para la detección de las zonas quemadas. Los resultados identificaron al índice espectral NBR como el más adecuado y confirman la problemática derivada de los incendios en dos de los espacios naturales considerados, con alto valores de ocurrencia y recurrencia.S