Spectral averaging techniques for Jacobi matrices

Spectral averaging techniques for one-dimensional discrete Schroedinger operators are revisited and extended. In particular, simultaneous averaging over several parameters is discussed. Special focus is put on proving lower bounds on the density of the averaged spectral measures. These Wegner type estimates are used to analyze stability properties for the spectral types of Jacobi matrices under local perturbations

¿Puede hablarse de acumulación y progreso en las ciencias sociales?

No es inusual la opinión de que el conocimie1úo científico-social se caracteriza por una proliferación teórica que conspira contra toda posibilidad de afirmar que, en ese campo, se da alguna clase de progreso. Mucho pesa en este tipo de evaluación la renuencia de los teóricos a reconocer explícitamente influencias de otros investigadores en sus propias construcciones y desarrollos, así como la vigencia de una concepción de progreso cuya necesidad y pertinencia se pretende examinar en el presente trabajo. La presentación se articula a partir de la consideración de la que podría denominarse concepción dominante del progreso científico entre quienes estudian las teorías sociales desde un metanivel. Para ello se discutirán las posiciones sustentadas por Agnes Heller y Michel Foucault v se las contrastará con las nociones de progreso y acumulación emergentes de un análisis estructural, con especial alusión a los conceptos de red teórica y de holán teórico

A bacterial acetyltransferase targets the protein kinase ZIP1, a positive regulator of plant immunity

Pseudomonas syringae is a model bacterial pathogen that penetrates the leaf to reach the plant apoplast, where it replicates causing disease. In order to do that, the pathogen must interfere and suppress a two-tiered plant defense response: PTI (PAMP-Triggered Immunity, or basal resistance) and ETI (Effector-Triggered Immunity). P. syringae uses a type III secretion system to directly deliver effector proteins inside the plant cell cytosol, many of which are known to suppress PTI, some of which are known to trigger ETI, and a handful of which are known to suppress ETI. Bacterial infection can also trigger a systemic plant defense response that protects the plant against additional pathogen attacks known as SAR (Systemic Acquired Resistance). We are particularly interested in the molecular and cellular mechanisms involved in effector-mediated defense evasion by P. syringae, in particular those involved in the suppression of ETI and SAR, and/or mediation of hormone signaling. Here we present data describing effector-mediated interference with plant immunity, by means of acetylation of a key positive regulator of local and systemic responses. Our work identifies a novel plant target for effector function, and characterizes its function. This work illustrates how analyzing the means by which a given effector interferes with its target can provide novel information regarding eukaryotic molecular mechanisms.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. MINECO BIO2015-64391R y FEDE

Soil investigation using a participative approach for agri-environmental improvement in Monegros, Spain

5 Pags.- 1 Tabl.- 2 Figs.The saline wetlands of the Monegros Desert, in the center of the Ebro Basin (NE Spain), host valuable biodiversity and pedodiversity. A part of this area has been proposed for inclusion in the Natura 2000 E. U. Network. However, agricultural intensification is changing the area as more land is consolidated for new irrigation or is plowed to obtain CAP (Common Agricultural Policy) subsides. Soil mapping is needed to assist in the delimitation of natural habitats and make conservation compatible with agriculture. The methodology presented here to characterize agri-environmental areas takes into account current agricultural and environmental practices. The approach was participative, asking the opinion of farmers and agricultural and environmental officers about a new agrienvironmental measure which could be proposed to the Rural Development section of the CAP The measure would economize agriculture inputs in unproductive areas and also meet nature conservation purposes. A GIS data base was built for selecting the farming plots suitable for new agricultural practices favoring biodiversity and pedodiversity. At the local scale, we used remote sensing and pedodiversity criteria for selecting low productive areas to be prospected. The opinion po!! resulted in a positive response, with a 67% of the managed surface favoring a new CAP measure compatible with nature conservation. The po!! corifirmed the interest of thefarmers in having detailed maps of the soil features that limit crop production.MEC and FEDER funded this work within the Project AGL2006-01283.Peer reviewe

The bacterial effector HopZ1a acetylates ZIP1 kinase to suppress Arabidopsis defence responses

During the plant-pathogen interaction, disease or resistance are determined in the plant by a series of molecular events. The plant detects Pathogen-Associated Molecular Patterns (PAMPs), such as flagellin, triggering a defence response called PTI (PAMP-Triggered Immunity). Bacterial pathogens can in turn suppress such defence response through the translocation into the plant cell cytosol of virulence proteins, called effectors, via a Type Three Secretion System (T3SS). In resistant plants, intracellular receptors known as R proteins recognize these effectors, triggering a second line of defence, more specific and intense, called ETI (Effector-Triggered Immunity), which usually leads to programmed cell death known as HR (Hypersensitive Response). Pseudomonas syringae is a phytopathogenic bacterium whose virulence depends on a T3SS and its effector repertoire. Some strains include HopZ1a, an unusual effector which is able to suppress in Arabidopsis both local (PTI and ETI), and systemic (SAR, for Systemic Acquired Resistance) defences, by means of its acetyltransferase activity. In resistant Arabidopsis plants, HopZ1a acetylates the ZED1 pseudokinase, which is proposed to function as a decoy mimicking HopZ1a target in the plant: ZED1 modification activates an R-protein (ZAR1) to trigger HopZ1a-dependent ETI. None of the Arabidopsis proteins proposed to date as HopZ1a targets is a kinase, nor fully explains the effector´s defence suppression abilities. In this work we identify an Arabidopsis kinase that functions as a positive regulator of PTI, ETI and SAR, which interacts with HopZ1a and is acetylated by this effector in lysine residues essential for its kinase activity. Further, HopZ1a can specifically suppress the defence phenotypes resulting from ZIP1 expression in Arabidopsis. We propose that ZIP1 acetylation by HopZ1a interferes with its kinase activity, and consequently with positive defence signalling.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Novel U-Shaped D-A-D π-conjugated Systems with Mechanochromic Properties: An Experimental and Theoretical Vibrational Spectroscopic Investigation

Π-conjugated compounds have been widely studied in the last few decades due to their huge field of application in organic electronics. Specifically, stimuli-responsive Π-conjugated materials which are sensitive to external stimulus (i.e., temperature, pressure, etc) have several uses like sensors, probes and security inks, for example.1 In this work, we study two U-shape Donor-Acceptor-Donor (D-A-D) systems that are found to exhibit interesting thermal- and pressure-dependent properties. 2 They consist on two different conformers of phenothiazine-dibenzo[a,j]phenazine-phenothiazine which differs from the position of the phenothiazine respect to the dibenzophenzaine central core. Compound 1R is the equatorial-equatorial conformer and 1Y is the axial-axial conformer (Figure 1). The dibenzophenzaine group acts as an electron-acceptor whereas the phenothiazine unit acts as an electron-donor. It has been reported that this U-shape D-A-D compound shows a multi-active color changing in 3 steps and their luminescence changes with temperature, pressure and acid exposition.2 In this work, we aim to elucidate how the external stimuli (i.e. temperature, pressure, acid ambient) affects the molecular structure at both intra- and intermolecular level. To this end, we use UV-Vis absorption, Raman (Figure 1) and Infrared spectroscopy experiments in combination with DFT calculations.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Understanding the structure and reactivity of NiCu nanoparticles: An atomistic model

The structure of bimetallic NiCu nanoparticles (NP) is investigated as a function of their composition and size by means of Lattice MonteCarlo (LMC) and molecular dynamics (MD) simulations. According to our results, copper segregation takes place at any composition of the particles. We found that this feature is not size-dependent. In contrast, nickel segregation depends on the NP size. When the size increases, Ni atoms tend to remain in the vicinity of the surface and deeper. For smaller NPs, Ni atoms are located at the surface as well. Our results also showed that most of the metal atoms segregated at the surface area were found to decorate edges and/or form islands. Our findings agree qualitatively with the experimental data found in the literature. In addition, we comment on the reactivity of these nanoparticles.Fil: Quaino, Paola Monica. Universidad Nacional del Litoral. Instituto de Química Aplicada del Litoral. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Química Aplicada del Litoral.; Argentina. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Programa de Electroquímica Aplicada e Ingeniería Electroquímica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Belletti, Gustavo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Litoral. Instituto de Química Aplicada del Litoral. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Química Aplicada del Litoral.; Argentina. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Programa de Electroquímica Aplicada e Ingeniería Electroquímica; ArgentinaFil: Shermukhamedov, S. A.. Kazan National Research Technological University; RusiaFil: Glukhov, D. V.. Kazan National Research Technological University; RusiaFil: Santos, Elizabeth del Carmen. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; Argentina. Institute of Theoretical Chemistry; Alemania. Universitat Ulm; AlemaniaFil: Schmickler, Wolfgang. Universitat Ulm; Alemania. Institute of Theoretical Chemistry; AlemaniaFil: Nazmutdinov, Renat. Kazan National Research Technological University; Rusi

Pd/Ti electrocatalyst in technological significance reactions

New materials operating as future electrocatalysts into fuel cells or in environmental remediation processes are continuously under research. Here we studied palladium modified electrodes, such as Pd/Ti and Pd/GC (glassy carbon), which are electrochemically built and used in chromate detection, in oxygen reduction and alcohols oxidation reaction. The palladium material electrodeposited at constant potential was characterized by X-ray diffraction, and scanning electron microscopy. The response of Pd/Ti nanoelectrodes, by oxygen reduction was observed in alkaline and acid supporting electrolytes. The diffusion coefficient of 2 10-5 cm2/s with a transference of 4e -in 0.1M H2SO4 solution was calculated. A higher coefficient value in 0.05 M NaOH was evaluated, because Ti substrate is also active in oxygen reduction in alkaline media. The reduction of Cr(VI) with Pd/Ti electrode proceeds at +0.58 V vs Ag/AgCl in H2SO4 0.1M, with a diffusion coefficient of 2.210-5 0.01 cm2/s and a linear range between 0.019 -0.69 mM Cr(VI). The lowest sensitivity 0.5 M Cr(VI) was determined with Pd/Ti electrode in the range permissible by drinking water of The oxidation of alcohol molecules in alkaline environment showed by Tafel curves, the activity order on Pd/Ti electrocatalyts is ethanoln-propanol >ethylene glycol. The calibration curve obtained by anodic peak current density of cyclic voltammetries upon an increasing alcohol concentration (3 to 90 mM alcohol) in NaOH 0.05 M, permitted to evaluate an activity of PdTi(+0.1V)PdTi(-0.3V)>PdTi(-0.9V). The performance of Pd/Ti electrocatalysts was better when compared with a modified Pd/GC electrocatalyst, in the studied reactions.Fil: Aguirre, María del Carmen. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto de Física "Enrique Gaviola"; ArgentinaFil: Fuentes, A. S.. Universidad Nacional de Catamarca. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Filippin, A. F.. Universidad Nacional de Catamarca. Facultad de Ciencias Exactas y Naturales; Argentin

The moderating role of prior experience in technological acceptance models for ubiquitous computing services in urban environments

Ubiquitous computing services constitute a new information technology that can be used in thousands of potential applications and environments. Ubiquitous computing is also changing the classic paradigm of information technology as it is forcing social and cultural changes. Determining factors affecting the use of ubiquitous services is essential to correctly define the characteristics of new value added services. However, this study investigates not only these factors, but also the moderating effect of previous experience. Due to the technological nature of ubiquitous services, previous experience alters the way in which potential users face these services. Findings suggest that previous experience changes the way in which antecedent relates to basic TAM constructs. The derived research models and empirical results also provide valuable indicators for future research and managerial guidelines for the successful adoption of ubiquitous computing servicesJunta de Andalucia. Consejería de Economía, Innovación, Ciencia y Empleo P12-SEJ-32