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.

A Multinational Survey of Risk Factors for Infection with Extended-Spectrum β-Lactamase-Producing Enterobacteriaceae in Nonhospitalized Patients

Abstract: Infections caused by extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae are increasing in frequency and are associated with high mortality rates. Circulation of CTX-M-type ESBLs in the community is of particular concern, because it may confound standard infection-control measures.

N6-methyl-adenine: an epigenetic signal for DNA-protein interactions.

Abstract: N(6)-methyl-adenine is found in the genomes of bacteria, archaea, protists and fungi. Most bacterial DNA adenine methyltransferases are part of restriction-modification systems. Certain groups of Proteobacteria also harbour solitary DNA adenine methyltransferases that provide signals for DNA-protein interactions. In gamma-proteobacteria, Dam methylation regulates chromosome replication, nucleoid segregation, DNA repair, transposition of insertion elements and transcription of specific genes. In Salmonella, Haemophilus, Yersinia and Vibrio species and in pathogenic Escherichia coli, Dam methylation is required for virulence. In alpha-proteobacteria, CcrM methylation regulates the cell cycle in Caulobacter, Rhizobium and Agrobacterium, and has a role in Brucella abortus infection.

Litter mass loss rates in pine forests of Europe and Eastern United States: some relationships with climate and litter quality

Abstract: The purpose of this study was to relate regional variation in litter mass-loss rates (first year) in pine forests to climate across a large, continental-scale area The variation in mass-loss rate was analyzed using 39 experimental sites spanning climatic regions from the subarctic to subtropical and Mediterranean: the latitudinal gradient ranged from 31 °N to 70 °N and may represent the the largest geographical area that has ever been sampled and observed for the purpose of studying biogeochemical processes Because of unified site design and uniform laboratory procedures, data from all sites were directly comparable and permitted a determination of the relative influence of climateversus substrate quality viewed from the perspective of broad regional scales Simple correlation applied to the entire data set indicated that annual actual evapotranspiration (AET) should be the leading climatic constraint on mass-loss rates (Radj 2 = 0496) The combination of AET, average July temp and average annual temp could explain about 70% of the sites' variability on litter mass-loss In an analysis of 23 Scots pine sites north of the Alps and Carpatians AET alone could account for about 65% of the variation and the addition of a substrate-quality variable was sufficiently significant to be used in a model The influence of litter quality was introduced into a model, using data from 11 sites at which litter of different quality had been incubated These sites are found in Germany, the Netherlands, Sweden and Finland At any one site most ( ≫ 90%) of the variation in mass-loss rates could be explained by one of the litter-quality variables giving concentration of nitrogen, phosphorus or water solubles However, even when these models included nitrogen or phosphorus even small changes in potential evapotranspiration resulted in large changes in early-phase decay rates Further regional subdivision of the data set, resulted in a range of strength in the relationship between loss rate and climatic variables, from very weak in Central Europe to strong for the Scandinavian and Atlantic coast sites (Radj 2 = 0912; AETversus litter mass loss) Much of the variation in observed loss rates could be related to continentalversus marine/Atlantic influences Inland locations had mass-loss rates lower than should be expected on the basis of for example AET alone Attempts to include seasonality variables were not successful It is clear that either unknown errors and biases, or, unknown variables are causing these regional differences in response to climatic variables Nevertheless these results show the powerful influence of climate as a control of the broad-scale geography of mass-loss rates and substrate quality at the stand level Some of these relationships between mass-loss rate and climatic variables are among the highest ever reported, probably because of the care taken to select uniform sites and experimental methods This suggest that superior, base line maps of predicted mass-loss rates could be produced using climatic data These models should be useful to predict the changing equilibrium litter dynamics resulting from climatic change

Quantum Key Distribution in the Holevo Limit

Abstract: A theorem by Shannon and the Holevo theorem impose that the efficiency of any protocol for quantum key distribution, $E$, defined as the number of secret (i.e., allowing eavesdropping detection) bits per transmitted bit plus qubit, is $E\ensuremath{\le}1$. The problem addressed here is whether the limit $E\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}1$ can be achieved. It is showed that it can be done by splitting the secret bits between several qubits and forcing Eve to have only a sequential access to the qubits, as proposed by Goldenberg and Vaidman. A protocol with $E\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}1$ based on polarized photons and in which Bob's state discrimination can be implemented with linear optical elements is presented.