Los libros de caballerías en América: huellas culturales y cultura impresa (1492-1516)

El propósito de este artículo es, a partir del análisis de la difusión impresa de la literatura caballeresca en lengua española, iniciar una reflexión sobre las dimensiones literarias y la difusión de la cultura de los súbditos de la Corona de Castilla que fueron desembarcando en tierras americanas durante los primeros viajes transatlánticos, aproximadamente entre 1492 y 1516.

Oligomerization and DNA binding of Ler, a master regulator of pathogenicity of enterohemorrhagic and enteropathogenic Escherichia coli

Ler is a DNA-binding, oligomerizable protein that regulates pathogenicity islands in enterohemorrhagic and enteropathogenic Escherichia coli strains. Ler counteracts the transcriptional silencing effect of H-NS, another oligomerizable nucleoid-associated protein. We studied the oligomerization of Ler in the absence and presence of DNA by atomic force microscopy. Ler forms compact particles with a multimodal size distribution corresponding to multiples of 35 units of Ler. DNA wraps around Ler particles that contain more than 1516 Ler monomers. The resulting shortening of the DNA contour length is in agreement with previous measurements of the length of DNA protected by Ler in footprinting assays. We propose that the repetition unit corresponds to the number of monomers per turn of a tight helical Ler oligomer. While the repressor (H-NS) and anti-repressor (Ler) have similar DNA-binding domains, their oligomerization domains are unrelated. We suggest that the different oligomerization behavior of the two proteins explains the opposite results of their interaction with the same or proximal regions of DNA.

Anàlisi dels aspectes mèdics de la mort violenta a Lleida a la Baixa Edat Mitjana: vol. 1

Aquest treball és el primer volum de la tesi presentada pel doctor Camps i Clemente, publicada pel Seminari Pere Mata per tal de donar-li major difusió. En aquesta tesi, l'autor estudia d'una forma extensa i profunda els episodis de mort violenta reportats a Lleida entre els anys 1308 i 1516. Els 342 procediments estudiats es guarden a la Paeria de Lleida i aporten dades sobre la realitat mèdico-sanitària i social de l'època baix-medieval.

ML approaches to channel estimation for pilot-aided multi-rate DS/CDMA systems

This paper analyzes the asymptotic performance of maximum likelihood (ML) channel estimation algorithms in wideband code division multiple access (WCDMA) scenarios. We concentrate on systems with periodic spreading sequences (period larger than or equal to the symbol span) where the transmitted signal contains a code division multiplexed pilot for channel estimation purposes. First, the asymptotic covariances of the training-only, semi-blind conditional maximum likelihood (CML) and semi-blind Gaussian maximum likelihood (GML) channelestimators are derived. Then, these formulas are further simplified assuming randomized spreading and training sequences under the approximation of high spreading factors and high number of codes. The results provide a useful tool to describe the performance of the channel estimators as a function of basicsystem parameters such as number of codes, spreading factors, or traffic to training power ratio.