University of Seville

About: University of Seville is a education organization based out in Seville, Andalucía, Spain. It is known for research contribution in the topics: Population & Model predictive control. The organization has 20098 authors who have published 47317 publications receiving 947007 citations. The organization is also known as: Universidad de Sevilla.

Differentiation of green, white, black, Oolong, and Pu-erh teas according to their free amino acids content.

Abstract: In this paper, the differentiation of green, black, Oolong, white, and Pu-erh teas has been carried out according to their free amino acid contents. Alanine, arginine, asparagine, aspartic acid, glutamic acid, isoleucine, histidine, leucine, phenylalanine, serine, theanine, threonine, and tyrosine have been determined by liquid chromatography with derivatization with o-phthalaldehyde and fluorescence detection. The chromatographic separation was achieved with a Hypersil ODS column and gradient elution. The amino acid contents were used as chemometric descriptors for classification purposes of different tea varieties. Principal component analysis, k-nearest neighbors, linear discriminant analysis, and artificial neural networks were applied to differentiate tea varieties. Using back-propagation multilayer perceptron artificial neural networks, 100% success in the classification was obtained. The most differentiating amino acids were glutamic acid, asparagine, serine, alanine, leucine, and isoleucine.

Experimental Test of Quantum Contextuality in Neutron Interferometry

Abstract: We performed an experimental test of the Kochen-Specker theorem based on an inequality derived from the Peres-Mermin proof, using spin-path (momentum) entanglement in a single neutron system. Following the strategy proposed by Cabello et al.[Phys. Rev. Lett. 100, 130404 (2008)], a Bell-like state was generated, and three expectation values were determined. The observed violation 2.291+-0.008not<=1 clearly shows that quantum mechanical predictions cannot be reproduced by noncontextual hidden-variable theories.

qnr Gene nomenclature.

Abstract: Since the plasmid-borne quinolone resistance gene qnr was reported in 1998 (8), many additional qnr alleles have been discovered on plasmids or the bacterial chromosome (reviewed in references 9 and 13). The plasmid-borne qnr genes currently comprise three families, qnrA, qnrB, and qnrS, differing from each other 40% or more in nucleotide sequence. Within each family, minor (≤10%) variation in sequence has defined a growing number of alleles. For the qnrA and qnrS families, the number of variants has been manageable, with general agreement on allele designations, but lately, the number of qnrB sequences submitted to GenBank has exploded, with the same qnrB allele number claimed for dissimilar sequences by different investigators and the same entry given new allele numbers from week to week.