University of Extremadura

About: University of Extremadura is a education organization based out in Badajoz, Spain. It is known for research contribution in the topics: Population & Hyperspectral imaging. The organization has 7856 authors who have published 18299 publications receiving 396126 citations. The organization is also known as: Universidad de Extremadura.

Discriminative Low-Rank Gabor Filtering for Spectral–Spatial Hyperspectral Image Classification

Abstract: Spectral–spatial classification of remotely sensed hyperspectral images has attracted a lot of attention in recent years. Although Gabor filtering has been used for feature extraction from hyperspectral images, its capacity to extract relevant information from both the spectral and the spatial domains of the image has not been fully explored yet. In this paper, we present a new discriminative low-rank Gabor filtering (DLRGF) method for spectral–spatial hyperspectral image classification. A main innovation of the proposed approach is that our implementation is accomplished by decomposing the standard 3-D spectral–spatial Gabor filter into eight subfilters, which correspond to different combinations of low-pass and bandpass single-rank filters. Then, we show that only one of the subfilters (i.e., the one that performs low-pass spatial filtering and bandpass spectral filtering) is actually appropriate to extract suitable features based on the characteristics of hyperspectral images. This allows us to perform spectral–spatial classification in a highly discriminative and computationally efficient way, by significantly decreasing the computational complexity (from cubic to linear order) compared with the 3-D spectral–spatial Gabor filter. In order to theoretically prove the discriminative ability of the selected subfilter, we derive an overall classification risk bound to evaluate the discriminating abilities of the features provided by the different subfilters. Our experimental results, conducted using different hyperspectral images, indicate that the proposed DLRGF method exhibits significant improvements in terms of classification accuracy and computational performance when compared with the 3-D spectral–spatial Gabor filter and other state-of-the-art spectral–spatial classification methods.

Volatile profiles of dry-cured meat products from three different Iberian x Duroc genotypes.

Abstract: Volatile profiles of two Iberian dry-cured products, dry-cured loin and ham, from three different Iberian × Duroc genotypes, was assessed Three groups of 10 pigs, each (5 males and 5 females) from different genotypes, were studied: GEN1 = ♂ Iberian × ♀ Duroc1; GEN2 = ♂ Duroc1 × ♀ Iberian; and GEN3 = ♂ Duroc2 × ♀ Iberian The genotype Duroc1 (DU1) corresponded to pigs selected for the production of dry-cured meat products (hams, loins, and shoulders), with a high level of fattening, while the genotype Duroc2 (DU2) corresponded to animals selected for meat production Genotype slightly affected the volatile profiles of both dry-cured meat products, although dry-cured loin from GEN3 showed higher hexanal content Dry-cured loin showed a volatile profile very different to that found in dry-cured ham Volatile compounds of dry-cured meat products were mainly originated by lipid and protein degradation Most of the volatile detected in both meat products came from lipid oxidation such as acids, aldehydes, ket

Kinetics of the Chemical Oxidation of the Pharmaceuticals Primidone, Ketoprofen, and Diatrizoate in Ultrapure and Natural Waters

Abstract: Oxidation of three pharmaceuticals (primidone, ketoprofen, and diatrizoate sodium) by means of several advanced oxidation processes including such as ozonation, UV radiation, and Fenton’s reagent has been studied. The influence of operating variables was established, and first-order rate constants were determined in most of the oxidation systems. Specifically, for the reactions with ozone, the following rate constants were obtained by means of a competition kinetic model: 1.0 ± 0.1, 0.40 ± 0.07, and 0.05 ± 0.01 M−1·s−1, for primidone, ketoprofen, and diatrizoate, respectively. The results showed that reaction with OH radicals was the major pathway for the oxidative transformation of these compounds. In the photodegradation experiments by 254 nm radiation, the quantum yields were also determined for every compound at different pH and temperatures. Additionally, the competition kinetic model, which was also used in Fenton’s reagent experiments, allowed to evaluate the rate constants for the reaction with hy...

Plant Phenolics: Bioavailability as a Key Determinant of Their Potential Health-Promoting Applications.

Abstract: Phenolic compounds are secondary metabolites widely spread throughout the plant kingdom that can be categorized as flavonoids and non-flavonoids. Interest in phenolic compounds has dramatically increased during the last decade due to their biological effects and promising therapeutic applications. In this review, we discuss the importance of phenolic compounds' bioavailability to accomplish their physiological functions, and highlight main factors affecting such parameter throughout metabolism of phenolics, from absorption to excretion. Besides, we give an updated overview of the health benefits of phenolic compounds, which are mainly linked to both their direct (e.g., free-radical scavenging ability) and indirect (e.g., by stimulating activity of antioxidant enzymes) antioxidant properties. Such antioxidant actions reportedly help them to prevent chronic and oxidative stress-related disorders such as cancer, cardiovascular and neurodegenerative diseases, among others. Last, we comment on development of cutting-edge delivery systems intended to improve bioavailability and enhance stability of phenolic compounds in the human body.