50 research outputs found
Differential expressed genes in ECV304 Endothelial-like Cells infected with Human Cytomegalovirus
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)
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
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,
, decreases with increasing inclination, while the faint-end slope,
, 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, , and
the LF for galaxies viewed face-on. The value of is quite independent
of galaxy luminosity in a given band, and the values of obtained in
this way for the 5 SDSS bands give an extinction curve which is a power law of
wavelength (), with a power index .
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 dimmer by about 0.5 magnitudes in the -band, and
about 1.2 magnitudes in the - 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
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
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 and to represent the
metallicity and age gradients, we found a median value of
for the metallicity gradient, with a dispersion . The
corresponding values for the age gradient were and
. 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
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
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]