Search results for "rings"
showing 10 items of 434 documents
Cluster organization and pore structure of ion channels formed by beticolin 3, a nonpeptidic fungal toxin
1999
Beticolin 3 (B3) belongs to a family of nonpeptidic phytotoxins produced by the fungus Cercospora beticola, which present a broad spectrum of cytotoxic effects. We report here that, at cytotoxic concentration (10 microM), B3 formed voltage-independent, weakly selective ion channels with multiple conductance levels in planar lipid bilayers. In symmetrical standard solutions, conductance values of the first levels were, respectively, 16 +/- 1 pS, 32 +/- 2 pS, and 57 +/- 2 pS (n = 4) and so on, any conductance level being roughly twice the lower one. Whether a cluster organization of elementary channels or different channel structures underlies this particular property was addressed by investi…
The coat protein of prunus necrotic ringspot virus specifically binds to and regulates the conformation of its genomic RNA
2003
AbstractBinding of coat protein (CP) to the 3′ nontranslated region (3′-NTR) of viral RNAs is a crucial requirement to establish the infection of Alfamo- and Ilarviruses. In vitro binding properties of the Prunus necrotic ringspot ilarvirus (PNRSV) CP to the 3′-NTR of its genomic RNA using purified E. coli- expressed CP and different synthetic peptides corresponding to a 26-residue sequence near the N-terminus were investigated by electrophoretic mobility shift assays. PNRSV CP bound to, at least, three different sites existing on the 3′-NTR. Moreover, the N-terminal region between amino acid residues 25 to 50 of the protein could function as an independent RNA-binding domain. Single exchan…
Artin monoids inject in their groups
2001
We prove that the natural homomorphism from an Artin monoid to its associated Artin group is always injective
Effect of water level and climatic factors on the radial growth of black alder
2011
Effect of water level and climatic factors on the radial growth of black alder Black alder (Alnus glutinosa (L.) Gaertn.) is a widespread tree species in Europe and the western part of the temperate climate zone. The area of forest in Latvia dominated by this tree species has substantially decreased due to wide-spread forest drainage. To predict future changes due to environmental change, it is extremely important to understand the function of ecosystems with black alder and their dynamics. Tree rings can be used as a proxy of past environmental factors. The aim of the study was to determine the effects of meteorological and hydrological factors on radial growth of black alder at two study …
Multipactor Mitigation in Coaxial Lines by Means of Permanent Magnets
2014
The main aim of this paper is the analysis of the feasibility of employing permanent magnets for the multipactor mitigation in a coaxial waveguide. First, the study of a coaxial line immersed in a uniform axial magnetic field shows that multipactor can be suppressed at any RF if the external magnetic field is strong enough. Both theoretical simulations and experimental tests validate this statement. Next, multipactor breakdown of a coaxial line immersed in a hollow cylindrical permanent magnet is analyzed. Numerical simulations show that multipactor can be suppressed in a certain RF range. The performed experimental test campaign demonstrates the capability of the magnet to avoid the multip…
Mutational analysis of the RNA-binding domain of the Prunus necrotic ringspot virus (PNRSV) movement protein reveals its requirement for cell-to-cell…
2005
AbstractThe movement protein (MP) of Prunus necrotic ringspot virus (PNRSV) is required for cell-to-cell movement. MP subcellular localization studies using a GFP fusion protein revealed highly punctate structures between neighboring cells, believed to represent plasmodesmata. Deletion of the RNA-binding domain (RBD) of PNRSV MP abolishes the cell-to-cell movement. A mutational analysis on this RBD was performed in order to identify in vivo the features that govern viral transport. Loss of positive charges prevented the cell-to-cell movement even though all mutants showed a similar accumulation level in protoplasts to those observed with the wild-type (wt) MP. Synthetic peptides representin…
Nanostructuring thin Au films on transparent conductive oxide substrates
2013
Fabrication processes of Au nanostructures on indium-tin-oxide (ITO) surface by simple, versatile, and low-cost bottom-up methodologies are investigated in this work. A first methodology exploits the patterning effects induced by nanosecond laser irradiations on thin Au films deposited on ITO surface. We show that after the laser irradiations, the Au film break-up into nanoclusters whose mean size and surface density are tunable by the laser fluence. A second methodology exploits, instead, the patterning effects of standard furnace thermal processes on the Au film deposited on the ITO. We observe, in this case, a peculiar shape evolution from pre-formed nanoclusters during the Au deposition…
Size filtering effect in vertical stacks of In(Ga)As/GaAs self-assembled quantum rings
2006
3 páginas, 3 figuras.
Revising midlatitude summer temperatures back to A.D. 600 based on a wood density network
2015
Annually resolved and millennium-long reconstructions of large-scale temperature variability are primarily composed of tree ring width (TRW) chronologies. Changes in ring width, however, have recently been shown to bias the ratio between low- and high-frequency signals. To overcome limitations in capturing the full spectrum of past temperature variability, we present a network of 15 maximum latewood density (MXD) chronologies distributed across the Northern Hemisphere extratropics. Independent subsets of continental-scale records consistently reveal high MXD before 1580 and after 1910, with below average values between these periods. Reconstructed extratropical summer temperatures reflect n…
Navigating the care between two distinct cultures: a qualitative study of the experiences of Arabic-speaking immigrants in Norwegian hospitals
2021
Abstract Background During the past decades, there has been an increase in the number of immigrants to European and Scandinavian countries. This has challenged the health-care systems, which cater to the needs of patients despite their cultural and linguistic barriers, in these countries. Most studies on this topic have focused on the perspectives of health-care providers in delivering their service. The purpose of this qualitative study was to explore how hospitalized Arabic-speaking patients experienced their interaction with the Norwegian health-care system. Methods In-depth interviews with 20 participants and researcher’s participant observation were conducted to explore the idiosyncrat…