50 research outputs found

    Differential expressed genes in ECV304 Endothelial-like Cells infected with Human Cytomegalovirus

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    Background: Human cytomegalovirus (HCMV) is a virus which has the potential to alter cellular gene expression through multiple mechanisms.Objective: With the application of DNA microarrays, we could monitor the effects of pathogens on host-cell gene expression programmes in great depth and on a broad scale.Methods: Changes in mRNA expression levels of human endothelial-like ECV304 cells following infection with human cytomegalovirus AD169 strain was analyzed by a microarray system comprising 21073 60-mer oligonucleotide probes which represent 18716 human genes or transcripts.Results: The results from cDNA microarray showed that there were 559 differential expressed genes consisted of 471 upregulated genes and 88 down-regulated genes. Real-time qPCR was performed to validate the expression of 6 selected genes (RPS24, MGC8721, SLC27A3, MST4, TRAF2 and LRRC28), and the results of which were consistent with those from the microarray. Among 237 biology processes, 39 biology processes were found to be related significantly to HCMV-infection. The signal transduction is the most significant biological process with the lowest p value (p=0.005) among all biological process which involved in response to HCMV infection.Conclusion: Several of these gene products might play key roles in virus-induced pathogenesis. These findings may help to elucidate the pathogenic mechanisms of HCMV caused diseases.Keywords: Human cytomegalovirus, microarray, Gene expression profiling; infectomicsAfrican Health Sciences 2013; 13(4): 864 - 87

    A new species of Boulenophrys from central Hunan Province, China (Anura: Megophryidae)

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    Abstract We re-examined the megophryinid population from Mt. Hengshan, Hunan Province, China previously identified as Boulenophrys brachykolos (under the name Megophrys brachykolos). Based on newly obtained molecular data, this population appears to be an independent lineage with a relatively distant phylogenetic relationship to B. brachykolos sensu stricto. Furthermore, this population exhibits distinct morphological characteristics that distinguish it from all its congeners. Therefore, we propose to recognize the Hengshan population of B. brachykolos as a new species, Boulenophrys hengshanensis sp. nov. described herein

    Inclination-Dependent Luminosity Function of Spiral Galaxies in the Sloan Digital Sky Survey: Implication for Dust Extinction

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    Using a samples of 61506 spiral galaxies selected from the SDSS DR2, we examine the luminosity function (LF) of spiral galaxies with different inclination angles. We find that the characteristic luminosity of the LF, LL^*, decreases with increasing inclination, while the faint-end slope, α\alpha, depends only weakly on it. The inclination-dependence of the LF is consistent with that expected from a simple model where the optical depth is proportional to the cosine of the inclination angle, and we use a likelihood method to recover both the coefficient in front of the cosine, γ\gamma, and the LF for galaxies viewed face-on. The value of γ\gamma is quite independent of galaxy luminosity in a given band, and the values of γ\gamma obtained in this way for the 5 SDSS bands give an extinction curve which is a power law of wavelength (τλn\tau\propto\lambda^{-n}), with a power index n=0.96±0.04n=0.96\pm0.04. Using the dust extinction for galaxies obtained by Kauffmann et al. (2003), we derive an `extinction-corrected' luminosity function for spiral galaxies. Dust extinction makes MM^* dimmer by about 0.5 magnitudes in the zz-band, and about 1.2 magnitudes in the uu- band. Since our analysis is based on a sample where selection effects are well under control, the dimming of edge-on galaxies relative to face-on galaxies is best explained by assuming that galaxy disks are optically thick in dust absorptions.Comment: 11 pages, 10 figures, accepted by Ap

    Extraction of Electron Self-Energy and Gap Function in the Superconducting State of Bi_2Sr_2CaCu_2O_8 Superconductor via Laser-Based Angle-Resolved Photoemission

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    Super-high resolution laser-based angle-resolved photoemission measurements have been performed on a high temperature superconductor Bi_2Sr_2CaCu_2O_8. The band back-bending characteristic of the Bogoliubov-like quasiparticle dispersion is clearly revealed at low temperature in the superconducting state. This makes it possible for the first time to experimentally extract the complex electron self-energy and the complex gap function in the superconducting state. The resultant electron self-energy and gap function exhibit features at ~54 meV and ~40 meV, in addition to the superconducting gap-induced structure at lower binding energy and a broad featureless structure at higher binding energy. These information will provide key insight and constraints on the origin of electron pairing in high temperature superconductors.Comment: 4 pages, 4 figure

    Optical and Near-Infrared Color Profiles in Nearby Early-Type Galaxies and The Implied Age and Metallicity Gradients

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    We present results of age and metallicity gradient analysis inferred from both optical and near-infrared surface photometry. The analysis is based on a sample of 36 nearby early-type galaxies, obtained from the Early Data Release of the Sloan Digital Sky Survey and the Two Micron All Sky Survey. Surface brightness profiles were derived in each band, and used to study the color gradients of the galaxies. Using simple stellar population models with both optical and near infrared colors, we may interpret the color gradients in term of age and metallicity gradients of galaxies. Using gZdlogZmet/dlogRg_Z \equiv d \log Z_{\rm met} / d \log R and gA=dlogAge/dlogRg_A = d \log {\rm Age} / d \log R to represent the metallicity and age gradients, we found a median value of gZ=0.25±0.03g_Z=-0.25\pm 0.03 for the metallicity gradient, with a dispersion σgZ=0.19±0.02\sigma_{g_Z}=0.19\pm0.02. The corresponding values for the age gradient were gA=0.02±0.04g_A=0.02\pm 0.04 and σgA=0.25±0.03\sigma_{g_A}=0.25\pm0.03. These results are in good agreement with recent observational results, as well as with recent simulations that suggest both monolithic collapse and major merger have played important roles in the formation of early-type galaxies. Our results demonstrate the potential of using multi-waveband colors obtained from current and future optical and infrared surveys in constraining the age and metallicity gradients of early-type galaxies.Comment: 40 pages, 14 figures. Revised version. Accepted by Ap

    Sorghum and pearl millet production in southern Africa

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    Sorghum and pearl millet are SADC's second and third most important cereal grains in terms of production area. Farmers in southern Africa annually sow over 1.9 million ha of sorghum and 0.9 million ha of pearl millet (Table 1). This compares with an aggregate production area of 12 million ha of maize. The area sown to sorghum and pearl millet in SADC has generally been increasing with the growth of smallholder farming populations

    A new species of Megophrys (Amphibia: Anura: Megophry-idae) from the northwestern Hunan Province, China

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    A new species of Megophrys (Amphibia: Anura: Megophryidae), Megophrys tuberogranulatus Shen, Mo et Li, sp. nov. (Holotype HNUL 03080902, adult male, SVL: 38.2 mm), from Sangzhi County, Hunan Province, is described. Megophrys tuberogranulatus is closely related to both Megophrys kuatunensis and Megophrys minor. Characters of the new species that differentiate this species from close relatives are skin granulated with big tubercles on the dorsal sides of both thigh and tibia, the bigger inner metacarpal tubercle, upper eyelid wider than the interorbital space, hind limbs longer, overlapping of the left and right calcaneal parts. The type specimens are deposited in the Animal Museum of Life Sciences College of Hunan Normal University [Current Zoology 56 (4): 432–436, 2010]
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