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Binary Interactions (binary + interaction)
Selected AbstractsMunc18-1 as a key regulator of neurosecretionJOURNAL OF NEUROCHEMISTRY, Issue 1 2010Gayoung A. Han J. Neurochem. (2010) 115, 1,10. Abstract Munc18-1 plays essential roles in neurosecretion by interacting with syntaxin-1 and controlling the formation of the soluble N -ethylmaleimide-sensitive factor attachment protein receptors (SNARE) complex. At least three important functions of Munc18-1 have been proposed: (i) molecular chaperone of syntaxin-1 for appropriate localization and expression of syntaxin-1, (ii) priming/stimulation of the SNARE-mediated membrane fusion, and (iii) docking of large dense-core vesicles to the plasma membrane. Similarly, at least two different binding modes have been proposed for the interaction between Munc18-1 and syntaxin-1: (i) binary binding to a ,closed' conformation of syntaxin-1, and (ii) binding to the N-terminal peptide of syntaxin-1, which is thought to enable an interaction with the quaternary SNARE complex and/or further stabilize the binary interaction between Munc18-1 and closed syntaxin-1. Recent structural analyses have identified critical Munc18-1 residues implicated in these different modes of binding. These have recently been tested functionally in rescue experiments using Munc18-1 null neurons, chromaffin cells and Munc18-1/-2 knockdown PC12 cells, allowing remarkable progress to be made in the structural/functional understanding of Munc18-1. In this review, we summarize these recent advances and attempt to propose an updated model of the pleiotropic functions of Munc18-1 in neuroexocytosis. [source] Carbon-rich extremely metal poor stars: signatures of Population III asymptotic giant branch stars in binary systemsMONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 2 2007Herbert H. B. Lau ABSTRACT We use the Cambridge stellar evolution code stars to model the evolution and nucleosynthesis of zero-metallicity intermediate-mass stars. We investigate the effect of duplicity on the nucleosynthesis output of these systems and the potential abundances of the secondaries. The surfaces of zero-metallicity stars are enriched in CNO elements after second dredge-up. During binary interaction, such as Roche lobe overflow or wind accretion, metals can be released from these stars and the secondaries enriched in CNO isotopes. We investigate the formation of the two most metal poor stars known, HE 0107,5240 and HE 1327,2326. The observed carbon and nitrogen abundances of HE 0107,5240 can be reproduced by accretion of material from the companion-enhanced wind of a 7-M, star after second dredge-up, though oxygen and sodium are underproduced. We speculate that HE 1327,2326, which is richer in nitrogen and strontium, may similarly be formed by wind accretion in a later asymptotic giant branch phase after third dredge-up. [source] Preparation and characterization of polyalginate,glutaraldehyde membranes,Swelling analysis by microcalorimetry and adsorption kinetics of cationic dyeJOURNAL OF APPLIED POLYMER SCIENCE, Issue 2 2010Eunice F. S. Vieira Abstract Thin crosslinked polyalginate,glutaraldehyde membranes were prepared and characterized by Fourier-transformed infrared spectroscopy, thermal analysis (TG/DTG), and X-ray diffractometry. Microcalorimetric analyses have pointed out that water swellings of the membranes are slightly exothermic, and the swelling energies decrease with increasing temperature. The membranes were tested for the adsorption of methylene blue (MB) dye from aqueous solutions. The adsorption capacity of the membranes increased with increasing initial MB concentration and decreased with increasing temperature. It was observed that the MB adsorption kinetic data were best fitted by the Avrami model. Intraparticle diffusion of MB into the interior of the membranes was detected after 60 min of contact time. The MB adsorption on the membranes was also evaluated by three new 22 full factorial designs (36 experiments). It was found that binary interactions between initial dye concentration and temperature are statistically important for MB adsorption on the membranes. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source] Evolutionary population synthesis for binary stellar population at high spectral resolution: integrated spectral energy distributions and absorption-feature indicesMONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 2 2005Fenghui Zhang ABSTRACT Using evolutionary population synthesis, we present high-resolution (0.3 Å) integrated spectral energy distributions from 3000 to 7000 Å and absorption-line indices defined by the Lick Observatory Image Dissector Scanner (Lick/IDS) system, for an extensive set of instantaneous-burst binary stellar populations with binary interactions. The ages of the populations are in the range 1,15 Gyr and the metallicities are in the range 0.004,0.03. These high-resolution synthesis results can satisfy the needs of modern spectroscopic galaxy surveys, and are available on request. By comparing the synthetic continuum of populations at high and low resolution, we show that there is good agreement for solar metallicity and tolerable disagreement for non-solar metallicity. The strength of the Balmer lines at high spectral resolution is greater than that at low resolution for all metallicities. The comparison of Lick/IDS absorption-line indices at low and high resolution, both of which are obtained by the fitting functions, shows that the discrepancies in all indices except for TiO1 and TiO2 are insignificant for populations with Z= 0.004 and 0.02. The high-resolution Ca4227, Fe5015 and Mgb indices are redder than the corresponding low-resolution ones for populations with Z= 0.01 and 0.03; this effect lowers the derived age and metallicity of the population. The high-resolution Mg1, Fe5709 and Fe5782 indices are bluer than those at low resolution; this effect raises the age and metallicity. The discrepancy in these six indices is greater for populations with Z= 0.03 in comparison to Z= 0.01. At high resolution we compare the Lick/IDS spectral absorption indices obtained by using the fitting functions with those measured directly from the synthetic spectra. We find that the Ca4455, Fe4668, Mgb and Na D indices obtained by the use of the fitting functions are redder for all metallicities, Fe5709 is redder at Z= 0.03 and becomes bluer at Z= 0.01 and 0.004, and the other indices are bluer for all metallicities than the corresponding values measured directly from the synthetic spectra. [source] Ternary miscibility in blends of three polymers with balanced binary interactionsPOLYMER ENGINEERING & SCIENCE, Issue 3 2003E. M. Woo This study demonstrates and discusses ternary miscibility in a three-polymer blend system based on balanced binary interactions. A truly miscible ternary blend comprising poly(,-caprolactone) (PCL), poly(benzyl methacrylate) (PBzMA), and poly(vinyl methyl ether) (PVME), was discovered and reported. Miscibility with phase homogeneity (excluding the PCL crystalline domain) in a wide composition range has been demonstrated using criteria of thermal transition behavior, cloud point, and microscopy characterization. At ambient temperature, the three-polymer ternary system is completely miscible within the entire composition range (i.e., no immiscibility loop). However, at slightly elevated temperatures above the ambient. phase separation readily occurred in this originally miscible ternary blend. A quite low "lower critical solution temperature" (LCST) near 75°C was found for the ternary blend, which is much lower than any of those for the binary pairs. Balanced interactions with no offsetting ,, among the three binary pairs were a key factor leading to a ternary miscible system. [source] Morphology and properties of ternary polyamide 6/polyamide 66/elastomer blendsPOLYMERS FOR ADVANCED TECHNOLOGIES, Issue 1 2003D. Tomova Abstract The aim of the work presented is to evaluate the mechanisms and phase interactions in ternary blends based on different polyamides and functionalised elastomers, and to establish a correlation between the morphology controlled by the specific binary interactions, and physical and technological properties, respectively. The properties of the ternary system polyamide 6/polyamide 66/ elastomer depend on the specific blend morphology which is determined mainly by the differences of the surface tension of the components. A phase-in-phase structure was observed by microscopic study (AFM) in the ternary polyamide 6/polyamide 66/elastomer blends with maleic anhydride grafted ethene-octene copolymer, and a "quasi" phase-in-phase structure in blends with maleic anhydride grafted ethene-propene-diene copolymer as the elastomer phase. An incorporation of polyamide inside of the elastomer particles was observed in the first case due to the difunctionality of polyamide 66. This type of morphology causes an increased elongation at break and toughness of these blends. In comparison to the binary polyamide based blends the ternary blends show an increased elastic modulus, elongation at break and yield stress as well as a high impact strength at low temperatures up to ,20,°C. Copyright © 2003 John Wiley & Sons, Ltd. [source] Ternary complex formation between HvMYBS3 and other factors involved in transcriptional control in barley seedsTHE PLANT JOURNAL, Issue 2 2006I. Rubio-Somoza Summary The SHAQKYF R1MYB transcription factor (TF) HvMYBS3 from barley is an activator of gene expression both during endosperm development and in aleurone cells upon seed germination. Its mRNA was detected as early as 10 days after flowering in developing barley endosperm, with a peak at 18 days, and in aleurone cells at 8 h after water imbibition, as shown by Northern blot and in situ hybridization analyses. The HvMYBS3 protein expressed in bacteria binds to oligonucleotides containing a GATA core derived from the promoters of: (i) the developing endosperm gene Itr1 (5,- GATAAGATA -3,) encoding trypsin inhibitor BTI-CMe, and (ii) the post-germinating aleurone gene Amy6.4 (5,-TATCCAC-3,/5,-GTGGATA -3,) encoding a high-pI , -amylase. Transient expression experiments in co-bombarded developing endosperms and in barley aleurone layers demonstrated that HvMYBS3 trans -activated transcription both from Itr1 and Amy6.4 promoters, in contrast with a previously reported seed-expressed R1MYB, HvMCB1, which was an activator of Itr1 and a transcriptional repressor of the Amy6.4 gene. In the yeast three-hybrid system, the HvMYBS3 protein formed a ternary complex with BPBF and BLZ2, two important seed TFs. However, no binary interactions could be detected between HvMYBS3 and BLZ2 or between HvMYBS3 and BPBF. [source] | |||||||||||||