Pectic homogalacturonan masks abundant sets of xyloglucan epitopes in plant cell walls

<p>Abstract</p> <p>Background</p> <p>Molecular probes are required to detect cell wall polymers <it>in-situ </it>to aid understanding of their cell biology and several studies have shown that cell wall epitopes have restricted occurrences across sections of plant organs indicating that cell wall structure is highly developmentally regulated. Xyloglucan is the major hemicellulose or cross-linking glycan of the primary cell walls of dicotyledons although little is known of its occurrence or functions in relation to cell development and cell wall microstructure.</p> <p>Results</p> <p>Using a neoglycoprotein approach, in which a XXXG heptasaccharide of tamarind seed xyloglucan was coupled to BSA to produce an immunogen, we have generated a rat monoclonal antibody (designated LM15) to the XXXG structural motif of xyloglucans. The specificity of LM15 has been confirmed by the analysis of LM15 binding using glycan microarrays and oligosaccharide hapten inhibition of binding studies. The use of LM15 for the analysis of xyloglucan in the cell walls of tamarind and nasturtium seeds, in which xyloglucan occurs as a storage polysaccharide, indicated that the LM15 xyloglucan epitope occurs throughout the thickened cell walls of the tamarind seed and in the outer regions, adjacent to middle lamellae, of the thickened cell walls of the nasturtium seed. Immunofluorescence analysis of LM15 binding to sections of tobacco and pea stem internodes indicated that the xyloglucan epitope was restricted to a few cell types in these organs. Enzymatic removal of pectic homogalacturonan from equivalent sections resulted in the abundant detection of distinct patterns of the LM15 xyloglucan epitope across these organs and a diversity of occurrences in relation to the cell wall microstructure of a range of cell types.</p> <p>Conclusion</p> <p>These observations support ideas that xyloglucan is associated with pectin in plant cell walls. They also indicate that documented patterns of cell wall epitopes in relation to cell development and cell differentiation may need to be re-considered in relation to the potential masking of cell wall epitopes by other cell wall components.</p

SITUAÇÃO AMBIENTAL DO IGARAPÉ MIRANDINHA (CANALIZAÇÃO)

A ação antrópica, associada especialmente à ocupação populacional de forma desordenada, tem acarretado diversos problemas ambientais aos igarapés urbanos de Boa Vista, levando os gestores públicos a desenvolverem diversos tipos de ação nessas áreas, como por exemplo, a canalização de trechos de alguns igarapés. Dentro desse contexto, o presente trabalho propõe a abordagem da canalização do igarapé Mirandinha, destacando seus principais impactos para a sociedade e o meio ambiente. Conforme pode-se observar, o igarapé Mirandinha já possui parte significativa de seu trecho canalizado, o que provocou a modificação completa da morfologia do leito do canal e também a alteração das margens do igarapé na área canalizada, descaracterizando totalmente a configuração natural do mesmo. Palavras-chave: Igarapé Mirandinha, Situação Ambiental, Canalização. ABSTRACT The action human, especially associated to the population occupation in a disordered way, it has been carting several environmental problems to the urban creek of Boa Vista, taking the public managers develop her several action types in those areas, as for instance, the canalization of passages of some creeks. Inside of that context, the present work proposes the approach of the canalization of the Mirandinha creek, detaching their main impacts for the society and the environment. As it can be observed, the Mirandinha creek already possesses significant part of his channeled passage, what provoked the complete modification of the morphology of the bed of the channel and also the alteration of the margins of the creek in the channeled area, descaracterizando totally the natural configuration of the same. Key-words: Mirandinha creek, Environmental Situation, Canalization. DOI: 10.5654/actageo2008.0204.000

SITUAÇÃO AMBIENTAL DO IGARAPÉ MIRANDINHA (CANALIZAÇÃO)

A ação antrópica, associada especialmente à ocupação populacional de forma desordenada, tem acarretado diversos problemas ambientais aos igarapés urbanos de Boa Vista, levando os gestores públicos a desenvolverem diversos tipos de ação nessas áreas, como por exemplo, a canalização de trechos de alguns igarapés. Dentro desse contexto, o presente trabalho propõe a abordagem da canalização do igarapé Mirandinha, destacando seus principais impactos para a sociedade e o meio ambiente. Conforme pode-se observar, o igarapé Mirandinha já possui parte significativa de seu trecho canalizado, o que provocou a modificação completa da morfologia do leito do canal e também a alteração das margens do igarapé na área canalizada, descaracterizando totalmente a configuração natural do mesmo. Palavras-chave: Igarapé Mirandinha, Situação Ambiental, Canalização. ABSTRACT The action human, especially associated to the population occupation in a disordered way, it has been carting several environmental problems to the urban creek of Boa Vista, taking the public managers develop her several action types in those areas, as for instance, the canalization of passages of some creeks. Inside of that context, the present work proposes the approach of the canalization of the Mirandinha creek, detaching their main impacts for the society and the environment. As it can be observed, the Mirandinha creek already possesses significant part of his channeled passage, what provoked the complete modification of the morphology of the bed of the channel and also the alteration of the margins of the creek in the channeled area, descaracterizando totally the natural configuration of the same. Key-words: Mirandinha creek, Environmental Situation, Canalization. DOI: 10.5654/actageo2008.0204.000

On the Easy Use of Scientific Computing Services for Large Scale Linear Algebra and Parallel Decision Making with the P-Grade Portal

International audienceScientific research is becoming increasingly dependent on the large-scale analysis of data using distributed computing infrastructures (Grid, cloud, GPU, etc.). Scientific computing (Petitet et al. 1999) aims at constructing mathematical models and numerical solution techniques for solving problems arising in science and engineering. In this paper, we describe the services of an integrated portal based on the P-Grade (Parallel Grid Run-time and Application Development Environment) portal (http://www.p-grade.hu) that enables the solution of large-scale linear systems of equations using direct solvers, makes easier the use of parallel block iterative algorithm and provides an interface for parallel decision making algorithms. The ultimate goal is to develop a single sign on integrated multi-service environment providing an easy access to different kind of mathematical calculations and algorithms to be performed on hybrid distributed computing infrastructures combining the benefits of large clusters, Grid or cloud, when needed

Thermally Induced Solid-Phase Quasi-Intramolecular Redox Reactions of [Hexakis(urea-O)iron(III)] Permanganate: An Easy Reaction Route to Prepare Potential (Fe,Mn)O x Catalysts for CO2 Hydrogenation

Research on new reaction routes and precursors to prepare catalysts for CO2 hydrogenation has enormous importance. Here, we report on the preparation of the permanganate salt of the urea-coordinated iron(III), [hexakis(urea-O)iron(III)]permanganate ([Fe(urea-O)6](MnO4)3) via an affordable synthesis route and preliminarily demonstrate the catalytic activity of its (Fe,Mn)Ox thermal decomposition products in CO2 hydrogenation. [Fe(urea-O)6](MnO4)3 contains O-coordinated urea ligands in octahedral propeller-like arrangement around the Fe3+ cation. There are extended hydrogen bond interactions between the permanganate ions and the hydrogen atoms of the urea ligands. These hydrogen bonds serve as reaction centers and have unique roles in the solid-phase quasi-intramolecular redox reaction of the urea ligand and the permanganate anion below the temperature of ligand loss of the complex cation. The decomposition mechanism of the urea ligand (ammonia elimination with the formation of isocyanuric acid and biuret) has been clarified. In an inert atmosphere, the final thermal decomposition product was manganese-containing wuestite, (Fe,Mn)O, at 800 °C, whereas in ambient air, two types of bixbyite (Fe,Mn)2O3 as well as jacobsite (Fe,Mn)T-4(Fe,Mn)OC-62O4), with overall Fe to Mn stoichiometry of 1:3, were formed. These final products were obtained regardless of the different atmospheres applied during thermal treatments up to 350 °C. Disordered bixbyite formed first with inhomogeneous Fe and Mn distribution and double-size supercell and then transformed gradually into common bixbyite with regular structure (and with 1:3 Fe to Mn ratio) upon increasing the temperature and heating time. The (Fe,Mn)Ox intermediates formed under various conditions showed catalytic effect in the CO2 hydrogenation reaction with <57.6% CO2 conversions and <39.3% hydrocarbon yields. As a mild solid-phase oxidant, hexakis(urea-O)iron(III) permanganate, was found to be selective in the transformation of (un)substituted benzylic alcohols into benzaldehydes and benzonitriles

Probing effective field theory operators in the associated production of top quarks with a Z boson in multilepton final states at root s=13 TeV

Peer reviewe

Combined searches for the production of supersymmetric top quark partners in proton-proton collisions at root s=13 TeV

A combination of searches for top squark pair production using proton-proton collision data at a center-of-mass energy of 13 TeV at the CERN LHC, corresponding to an integrated luminosity of 137 fb(-1) collected by the CMS experiment, is presented. Signatures with at least 2 jets and large missing transverse momentum are categorized into events with 0, 1, or 2 leptons. New results for regions of parameter space where the kinematical properties of top squark pair production and top quark pair production are very similar are presented. Depending on themodel, the combined result excludes a top squarkmass up to 1325 GeV for amassless neutralino, and a neutralinomass up to 700 GeV for a top squarkmass of 1150 GeV. Top squarks with masses from 145 to 295 GeV, for neutralino masses from 0 to 100 GeV, with a mass difference between the top squark and the neutralino in a window of 30 GeV around the mass of the top quark, are excluded for the first time with CMS data. The results of theses searches are also interpreted in an alternative signal model of dark matter production via a spin-0 mediator in association with a top quark pair. Upper limits are set on the cross section for mediator particle masses of up to 420 GeV