Divergent DNA Methylation Provides Insights into the Evolution of Duplicate Genes in Zebrafish

The evolutionary mechanism, fate and function of duplicate genes in various taxa have been widely studied; however, the mechanism underlying the maintenance and divergence of duplicate genes in Danio rerio remains largely unexplored. Whether and how the divergence of DNA methylation between duplicate pairs is associated with gene expression and evolutionary time are poorly understood. In this study, by analyzing bisulfite sequencing (BS-seq) and RNA-seq datasets from public data, we demonstrated that DNA methylation played a critical role in duplicate gene evolution in zebrafish. Initially, we found promoter methylation of duplicate genes generally decreased with evolutionary time as measured by synonymous substitution rate between paralogous duplicates (Ks). Importantly, promoter methylation of duplicate genes was negatively correlated with gene expression. Interestingly, for 665 duplicate gene pairs, one gene was consistently promoter methylated, while the other was unmethylated across nine different datasets we studied. Moreover, one motif enriched in promoter methylated duplicate genes tended to be bound by the transcription repression factor FOXD3, whereas a motif enriched in the promoter unmethylated sequences interacted with the transcription activator Sp1, indicating a complex interaction between the genomic environment and epigenome. Besides, body-methylated genes showed longer length than body-unmethylated genes. Overall, our results suggest that DNA methylation is highly important in the differential expression and evolution of duplicate genes in zebrafish.</p

Poly[[{μ3-dihydrogen [(pyridin-4-yl­methyl­imino)­bis­(methyl­ene)]diphos­phon­ato-κ5 O:O′,N,O′′:N′}copper(II)] dihydrate]

In the title polymer, {[Cu(C8H12N2O6P2)]·2H2O}n, the geometry of the five-coordinate CuII ion can best be described as slightly distorted square-pyramidal formed by one N and two O atoms of an N(CH2PO3H)2 group and one N atom from a pyridine ring. The elongated apex of the pyramid is occupied by one O atom from a third diphospho­nate ligand. The inter­connection of Cu2+ ions by the diphospho­nate ligands results in the formation of a double-chain array along the b axis, in which the two sub-chains are inter­locked by pairs of PO3 groups. The outside of each sub-chain is decorated by other PO3 groups. These double chains are further assembled into a three-dimensional supra­molecular architecture via a large number of O—H⋯O hydrogen bonds between the phospho­nate groups and lattice water mol­ecules

Characterization and activity of N doped TiO2 supported VPO catalysts for NO oxidation

AbstractNitrogen (N) doped TiO2 supported vanadium phosphorus oxide (VPO) catalysts were prepared and tested for catalytic oxidation of NO. The experimental results showed that 0.1V(5)PO/TiN(1) was the optimal catalyst for NO oxidation and the NO conversion could reach 61% at temperature of 350°C. The physico–chemical properties of 0.1V(5)PO/TiN(1) catalyst were characterized by Brunauer–Emmett–Teller measurements (BET), Photoluminescence (PL), X–ray photoelectron spectroscopy (XPS), Infrared spectroscopy measurements of NH3 adsorbed on catalysts (NH3–IR), and Infrared Fourier transform spectroscopy (FTIR). The PL and XPS spectra revealed that the oxygen storage capacity and catalytic activity of VPO/Ti catalyst can be improved by nitrogen doping. The H2–TPR profile also indicated that V(5)PO/TiN(1) catalyst had a superior redox property. Activity test results and FTIR spectra showed that 0.1V(5)PO/TiN(1) catalysts had a superior resistivity to SO2 and the NO oxidation rate is above 50% at temperature of 350°C when SO2 concentration is 200ppm to 800ppm

Deadline Constrained Cloud Computing Resources Scheduling through an Ant Colony System Approach

Cloud computing resources scheduling is essential for executing workflows in the cloud platform because it relates to both execution time and execution cost. In this paper, we adopt a model that optimizes the execution cost while meeting deadline constraints. In solving this problem, we propose an Improved Ant Colony System (IACS) approach featuring two novel strategies. Firstly, a dynamic heuristic strategy is used to calculate a heuristic value during an evolutionary process by taking the workflow topological structure into consideration. Secondly, a double search strategy is used to initialize the pheromone and calculate the heuristic value according to the execution time at the beginning and to initialize the pheromone and calculate heuristic value according to the execution cost after a feasible solution is found. Therefore, the proposed IACS is adaptive to the search environment and to different objectives. We have conducted extensive experiments based on workflows with different scales and different cloud resources. We compare the result with a particle swarm optimization (PSO) approach and a dynamic objective genetic algorithm (DOGA) approach. Experimental results show that IACS is able to find better solutions with a lower cost than both PSO and DOGA do on various scheduling scales and deadline conditions

Plasma Lipoprotein-associated Phospholipase A2 in Patients with Metabolic Syndrome and Carotid Atherosclerosis

<p>Abstract</p> <p>Background</p> <p>Lipoprotein-associated phospholipase A₂(Lp-PLA₂) is a recently identified and potentially useful plasma biomarker for cardiovascular and atherosclerotic diseases. However, the correlation between the Lp-PLA₂activity and carotid atherosclerosis remains poorly investigated in patients with metabolic syndrome (MetS). The present study aimed to evaluate the potential role of Lp-PLA₂as a comprehensive marker of metabolic syndrome in individuals with and without carotid atherosclerosis.</p> <p>Methods</p> <p>We documented 118 consecutive patients with MetS and 70 age- and sex-matched healthy subjects served as controls. The patients were further divided into two groups: 39 with carotid plaques and 79 without carotid plaques to elucidate the influence of Lp-PLA₂on carotid atherosclerosis. The plasma Lp-PLA₂activity was measured by using ELISA method and carotid intimal-media thickness (IMT) was performed by ultrasound in all participants.</p> <p>Results</p> <p>Lp-PLA₂activity was significantly increased in MetS subgroups when compared with controls, and was higher in patients with carotid plaques than those without plaques (<it>P </it>< 0.05). Furthermore, we found that significant difference in Lp-PLA₂was obtained between patients with three and four disorders of metabolic syndrome (<it>P </it>< 0.01). Age (β = 0.183, <it>P </it>= 0.029), LDL-cholesterol (β = 0.401, <it>P </it>= 0.000) and waist-hip ratio (β = 0.410, <it>P </it>= 0.000) emerged as significant and independent determinants of Lp-PLA₂activity. Multiple stepwise regression analysis revealed that LDL-cholesterol (β = 0.309, <it>P </it>= 0.000), systolic blood pressure (β = 0.322, <it>P </it>= 0.002) and age (β = 0.235, <it>P </it>= 0.007) significantly correlated with max IMT, and Lp-PLA₂was not an independent predictor for carotid IMT.</p> <p>Conclusions</p> <p>Lp-PLA₂may be a modulating factor for carotid IMT via age and LDL-cholesterol, not independent predictor in the pathophysiological process of carotid atherosclerosis in patients with MetS.</p

Plasmoid ejection and secondary current sheet generation from magnetic reconnection in laser-plasma interaction

Reconnection of the self-generated magnetic fields in laser-plasma interaction was first investigated experimentally by Nilson {\it et al.} [Phys. Rev. Lett. 97, 255001 (2006)] by shining two laser pulses a distance apart on a solid target layer. An elongated current sheet (CS) was observed in the plasma between the two laser spots. In order to more closely model magnetotail reconnection, here two side-by-side thin target layers, instead of a single one, are used. It is found that at one end of the elongated CS a fan-like electron outflow region including three well-collimated electron jets appears. The ($>1$ MeV) tail of the jet energy distribution exhibits a power-law scaling. The enhanced electron acceleration is attributed to the intense inductive electric field in the narrow electron dominated reconnection region, as well as additional acceleration as they are trapped inside the rapidly moving plasmoid formed in and ejected from the CS. The ejection also induces a secondary CS

Metal-bonded perovskite lead hydride with phonon-mediated superconductivity up to 46 K under atmospheric pressure

In the search for high-temperature superconductivity in hydrides, a plethora of multi-hydrogen superconductors have been theoretically predicted, and some have been synthesized experimentally under ultrahigh pressures of several hundred GPa. However, the impracticality of these high-pressure methods has been a persistent issue. In response, we propose a new approach to achieve high-temperature superconductivity under atmospheric pressure by implanting hydrogen into lead to create a stable few-hydrogen metal-bonded perovskite, Pb$_4$H. This approach diverges from the popular design methodology of multi-hydrogen covalent high critical temperature ($T_c$) superconductors under ultrahigh pressure. By solving the anisotropic Migdal-Eliashberg (ME) equations, we demonstrate that perovskite Pb$_4$H is a typical phonon-mediated superconductor with a $T_c$ of 46 K, which is six times higher than that of bulk Pb (7.22 K) and higher than that of MgB$_2$ (39 K). The high $T_c$ can be attributed to the strong electron-phonon coupling (EPC) strength of 2.45, which arises from hydrogen implantation in lead that induces several high-frequency optical phonon modes with a relatively large phonon linewidth resulting from H atom vibration. The metallic-bonding in perovskite Pb$_4$H not only improves the structural stability but also guarantees better ductility than the widely investigated multi-hydrogen, iron-based, and cuprate superconductors. These results suggest that there is potential for the exploration of new high-temperature superconductors under atmospheric pressure and may reignite interest in their experimental synthesis soon.Comment: 6 pages, 4 figure