Modulation of Rab GTPase function by a protein phosphocholine transferase.

The intracellular pathogen Legionella pneumophila modulates the activity of host GTPases to direct the transport and assembly of the membrane-bound compartment in which it resides. In vitro studies have indicated that the Legionella protein DrrA post-translationally modifies the GTPase Rab1 by a process called AMPylation. Here we used mass spectrometry to investigate post-translational modifications to Rab1 that occur during infection of host cells by Legionella. Consistent with in vitro studies, DrrA-mediated AMPylation of a conserved tyrosine residue in the switch II region of Rab1 was detected during infection. In addition, a modification to an adjacent serine residue in Rab1 was discovered, which was independent of DrrA. The Legionella effector protein AnkX was required for this modification. Biochemical studies determined that AnkX directly mediates the covalent attachment of a phosphocholine moiety to Rab1. This phosphocholine transferase activity used CDP-choline as a substrate and required a conserved histidine residue located in the FIC domain of the AnkX protein. During infection, AnkX modified both Rab1 and Rab35, which explains how this protein modulates membrane transport through both the endocytic and exocytic pathways of the host cell. Thus, phosphocholination of Rab GTPases represents a mechanism by which bacterial FIC-domain-containing proteins can alter host-cell functions

Patologías presentes en la tumba calcolítica de la necrópolis "Huerta Montero". Almendralejo (Badajoz)

X Congreso Nacional de Paleopatología. Univesidad Autónoma de Madrid, septiembre de 200

Etnografía de la Andalucía Occidental

Sin resume

A CMOS Imager for Time-of-Flight and Photon Counting Based on Single Photon Avalanche Diodes and In-Pixel Time-to-Digital Converters

The design of a CMOS image sensor based on single-photon avalanche-diode (SPAD) array with in-pixel time-to-digital converter (TDC) is presented. The architecture of the imager is thoroughly described with emphasis on the characterization of the TDCs array. It is targeted for 3D image reconstruction. Several techniques as fast quenching/recharge circuit with tunable dead-time and time gated-operation are applied to reduce the noise and the power consumption. The chip was fabricated in a 0.18 m standard CMOS process and implements a double functionality: time-of-flight (ToF) estimation and photon counting. The imager features a programmable time resolution of the array of TDCs down to 145 ps. The measured accuracy of the minimum time bin is lower than 1LSB DNL and 1.7 LSB INL. The TDC jitter over the full dynamic range is less than 1 LSB.Peer reviewe

Nuevos datos sobre "Myxomycetes" presentes en la provincia de Granada (España)

En el presente trabajo se aportan nuevos datos sobre el conocimiento de los Myxomycetes de Granada (sur de España), citándose catorce nuevas especies, entre las que ne destacan: Comatricha alta Preusz, Diderma trevelyanii (Grev.) Fr., Diderma umbilicatum Pers., Didymium bahiense Gottsberger, Didymium difforme (Pers.) S.F. Gray, Didymium trachysporum G. Lister, Lamproderma scintillans (Berk. & Br.) Morgan, Physarum contextum (Pers.) Pers., Physarum vernum Somm. y se amplía la corologia de varias especies ya citadas en anteriores trabajos. Se comenta la distribución en la Peninsula Ibérica, confeccionándose mapas de distribución de dichos tazones basados en cuadrícula UTM de 50 Km.This article shows a study on the Myxomycetes on the province of Granada (Spain). We have found fourteen new taxa for this province. Some of these are: Comatricha alta Preusz, Diderma trevelyanii(Gres.) Fr., Diderma umbilicatum Pers., Didymium bahiense Gottsberger, Didymium difforme (Pers.) S.F. Gray, Didymium trachysporum G. Lister, Lamproderma scintillans (Berk. & Br.) Morgan, Physarum contextum (Pers.) Pers., Physarum vernum Somm. Distribution maps are given. We also included new dates about the chorology another species

A vision-based monitoring system for very early automatic detection of forest fires

Trabajo presentado a la "I International Conference on Modelling, Monitoring and Management of Forest Fires" celebrada en Toledo del 17 al 19 de Septiembre de 2008.International Conference on Modelling, Monitoring and Management of Forest Fires I This paper describes a system capable of detecting smoke at the very beginning of a forest fire with a precise spatial resolution. The system is based on a wireless vision sensor network. Each sensor monitors a small area of vegetation by running on-site a tailored vision algorithm to detect the presence of smoke. This algorithm examines chromaticity changes and spatio-temporal patterns in the scene that are characteristic of the smoke dynamics at early stages of propagation. Processing takes place at the sensor nodes and, if that is the case, an alarm signal is transmitted through the network along with a reference to the location of the triggered zone - without requiring complex GIS systems. This method improves the spatial resolution on the surveilled area and reduces the rate of false alarms. An energy efficient implementation of the sensor/processor devices is crucial as it determines the autonomy of the network nodes. At this point, we have developed an ad hoc vision algorithm, adapted to the nature of the problem, to be integrated into a single-chip sensor/processor. As a first step to validate the feasibility of the system, we applied the algorithm to smoke sequences recorded with commercial cameras at real-world scenarios that simulate the working conditions of the network nodes. The results obtained point to a very high reliability and robustness in the detection process.This work is funded by Junta de Andalucía (CICE) through project 2006-TIC-2352.Peer Reviewe

Pezoloma ciliifera (P. Karst.) Korf, un discomicete nuevo para España

Pezoloma ciliif era (p. Karst) Korf, a rare species in the world, is reported for the flIst tirne in Spain, on base to Albarracín mountains findings (Teruel, Spain). A detailed iconographic -macro and microscopicstudy is made. Besides, its ecological preferences are confrrmed, having a saprophytic habit in behaviour areas, during surnrner, at high elevations.Pezoloma ciliifera (P. Karst) Korf, una especie rara en el mundo, es citada por vez primera de España, en base a hallazgos realizados en la Sierra de Albarracín (Teruel). Se acompaña un detallado estudio iconognifico rnacro y microscópico, al tiempo que se confinna su comportamiento saprotrófico, estival, en ambientes palustres de alta montaña

Quantum time uncertainty in Schwarzschild-anti-de Sitter black holes

The combined action of gravity and quantum mechanics gives rise to a minimum time uncertainty in the lowest order approximation of a perturbative scheme, in which quantum effects are regarded as corrections to the classical spacetime geometry. From the nonperturbative point of view, both gravity and quantum mechanics are treated on equal footing in a description that already contains all possible backreaction effects as those above in a nonlinear manner. In this paper, the existence or not of such minimum time uncertainty is analyzed in the context of Schwarzschild-anti-de Sitter black holes using the isolated horizon formalism. We show that from a perturbative point of view, a nonzero time uncertainty is generically present owing to the energy scale introduced by the cosmological constant, while in a quantization scheme that includes nonperturbatively the effects of that scale, an arbitrarily high time resolution can be reached.Comment: 10 pages, version published in Physical Review