Ito channels are octomeric complexes with four subunits of each Kv4.2 and K+ channel-interacting protein 2.

Mammalian voltage-gated K+ channels are assemblies of pore-forming alpha-subunits and modulating beta-subunits. To operate correctly, Kv4 alpha-subunits in the heart and central nervous system require recently identified beta-subunits of the neuronal calcium sensing protein family called K+ channel-interacting proteins (KChIPs). Here, Kv4.2.KChIP2 channels are purified, integrity of isolated complexes confirmed, molar ratio of the subunits determined, and subunit valence established. A complex has 4 subunits of each type, a stoichiometry expected for other channels employing neuronal calcium sensing beta-subunits

Three-dimensional structure of I(to); Kv4.2-KChIP2 ion channels by electron microscopy at 21 Angstrom resolution.

Regulatory KChIP2 subunits assemble with pore-forming Kv4.2 subunits in 4:4 complexes to produce native voltage-gated potassium (Kv) channels like cardiac I(to) and neuronal I(A) subtypes. Here, negative stain electron microscopy (EM) and single particle averaging reveal KChIP2 to create a novel approximately 35 x 115 x 115 Angstrom, intracellular fenestrated rotunda: four peripheral columns that extend down from the membrane-embedded portion of the channel to enclose the Kv4.2 "hanging gondola" (a platform held beneath the transmembrane conduction pore by four internal columns). To reach the pore from the cytosol, ions traverse one of four external fenestrae to enter the rotundal vestibule and then cross one of four internal windows in the gondola

Analysis of five deep-sequenced trio-genomes of the Peninsular Malaysia Orang Asli and North Borneo populations

BackgroundRecent advances in genomic technologies have facilitated genome-wide investigation of human genetic variations. However, most efforts have focused on the major populations, yet trio genomes of indigenous populations from Southeast Asia have been under-investigated.ResultsWe analyzed the whole-genome deep sequencing data (30x) of five native trios from Peninsular Malaysia and North Borneo, and characterized the genomic variants, including single nucleotide variants (SNVs), small insertions and deletions (indels) and copy number variants (CNVs). We discovered approximately 6.9 million SNVs, 1.2 million indels, and 9000 CNVs in the 15 samples, of which 2.7% SNVs, 2.3% indels and 22% CNVs were novel, implying the insufficient coverage of population diversity in existing databases. We identified a higher proportion of novel variants in the Orang Asli (OA) samples, i.e., the indigenous people from Peninsular Malaysia, than that of the North Bornean (NB) samples, likely due to more complex demographic history and long-time isolation of the OA groups. We used the pedigree information to identify de novo variants and estimated the autosomal mutation rates to be 0.81x10(-8) - 1.33x10(-8), 1.0x10(-9) - 2.9x10(-9), and 0.001 per site per generation for SNVs, indels, and CNVs, respectively. The trio-genomes also allowed for haplotype phasing with high accuracy, which serves as references to the future genomic studies of OA and NB populations. In addition, high-frequency inherited CNVs specific to OA or NB were identified. One example is a 50-kb duplication in DEFA1B detected only in the Negrito trios, implying plausible effects on host defense against the exposure of diverse microbial in tropical rainforest environment of these hunter-gatherers. The CNVs shared between OA and NB groups were much fewer than those specific to each group. Nevertheless, we identified a 142-kb duplication in AMY1A in all the 15 samples, and this gene is associated with the high-starch diet. Moreover, novel insertions shared with archaic hominids were identified in our samples.ConclusionOur study presents a full catalogue of the genome variants of the native Malaysian populations, which is a complement of the genome diversity in Southeast Asians. It implies specific population history of the native inhabitants, and demonstrated the necessity of more genome sequencing efforts on the multi-ethnic native groups of Malaysia and Southeast Asia

Web Technologies (GGC)

This Grants Collection for Web Technologies was created under a Round Nine ALG Textbook Transformation Grant. Affordable Learning Georgia Grants Collections are intended to provide faculty with the frameworks to quickly implement or revise the same materials as a Textbook Transformation Grants team, along with the aims and lessons learned from project teams during the implementation process. Documents are in .pdf format, with a separate .docx (Word) version available for download. Each collection contains the following materials: Linked Syllabus Initial Proposal Final Reporthttps://oer.galileo.usg.edu/compsci-collections/1015/thumbnail.jp

Uniform L1L^1 error bounds for semi-discrete finite element solutions of evolutionary integral equations

summary:In this paper, we consider the second-order continuous time Galerkin approximation of the solution to the initial problem $u_{t}+\int_{0}^{t}\beta (t-s) Au(s)ds=0,u(0)=v,t>0,$ where A is an elliptic partial-differential operator and $\beta(t)$ is positive, nonincreasing and log-convex on $(0,\infty)$ with $0\leq\beta(\infty)<\beta(0^{+})\leq\infty$. Error estimates are derived in the norm of $L^{1}_{t}(0,\infty;L^{2}_{x})$, and some estimates for the first order time derivatives of the errors are also given

Explosion characteristics of hydrous bio-ethanol in oxygen-enriched air

Hydrous bio-ethanol is a promising alternative fuel, which consumes less energy during the production than anhydrous bio-ethanol. However, hydrous bio-ethanol features a slow burning rate, leading to low combustion stability, or even misfire especially at a high water content. Preliminary research has shown that oxygen-enriched combustion (oxy-combustion) effectively solves the slow burning rate issue. However, oxy-combustion might increase the potential explosion hazard. Therefore, it is essential to study the explosion characteristics of hydrous bio-ethanol oxy-combustion before its application in practical engines. In this paper, an explosion characteristic study of hydrous bio-ethanol was carried out in a constant volume combustion chamber (CVCC). Hydrous bio-ethanol with 20 vol% water (E80W20) was selected for the investigations considering the tradeoff between production energy saving and burn rate. The boundary conditions for the experiments are initial pressures of 1–4 bar, initial temperatures of 358–418 K, air with the oxygen concentrations of 21–25% and equivalence ratios of 0.7–1.4. Explosion parameters such as explosion pressure, maximum rate of pressure rise, deflagration index, and combustion duration were analyzed. The results showed that both the explosion pressure and maximum rate of pressure rise increased linearly with the initial pressure. Deflagration index increased linearly with the oxygen concentration but it was insensitive to the initial temperature. In most cases, the deflagration index was lower than 20 MPa·m/s, revealing that E80W20 is relatively safe when it is combusted with air with a 23% oxygen content. This work paves the way for the application of hydrous bio-ethanol oxy-combustion in practical engines

Describing Strong Correlation with Block-Correlated Coupled Cluster Theory

A block-correlated coupled cluster (BCCC) method based on the generalized valence bond (GVB) wave function (GVB-BCCC in short) is proposed and implemented at the ab initio level, which represents an attractive multireference electronic structure method for strongly correlated systems. The GVB-BCCC method is demonstrated to provide accurate descriptions for multiple bond breaking in small molecules, although the GVB reference function is qualitatively wrong for the studied processes. For a challenging prototype of strongly correlated systems, tridecane with all 12 single C-C bonds at various distances, our calculations have shown that the GVB-BCCC2b method can provide highly comparable results as the density matrix renormalization group method for potential energy surfaces along simultaneous dissociation of all C-C bonds

Preparation, characterization and photocatalytic activity of silicon and sulfur codoped mesoporous titanium dioxide photocatalyst

A series of mesoporous titanium dioxide (MTiO2) photocatalysts codoped with silicon and sulfur has been prepared by a template method using tetraethyl orthosilicate, thiourea and tetrabutyl titanate (Ti(OC4H9)4) as precursors and Pluronic P123 as template. The photoabsorbance of the prepared photocatalysts has been measured by UV-vis diffusive reflectance spectroscopy and its microstructure characterized using scanning electron microscopy, diffraction (XRD) and N2 adsorption-desorption measurements. The microcrystal of the codoped photocatalyst consistest of anatase phase and is present in the form of almost spherical particle. The photocatalytic activity has been studied by photodegradation of methyl blue in aqueous solution under UV and visible light irradiation. The results show that the amount of dopants, silicon and sulfur, influence the photoactivity. The photocatalyst codoped with 1 mol% silicon and 2 mol% sulfur exhibites the highest photoactivity. The synergistic effect of silicon and sulfur codoping in improves the photocatalytic activity considerably