2,488 research outputs found
Genome-wide analyses of abiotic stress-related microRNAs and their targets in Arabidopsis thaliana
Abstract MicroRNAs (miRNAs) are known to regulate plant growth and development via regulating gene expression at both transcriptional and post-transcriptional levels. Although several miRNAs have been reported to be associated with abiotic stress responses in plant, systematic investigation of stress-related miRNAs and their targets in plants is limited. In this study, we systematically investigated stress-related miRNAs and their targets in Arabidopsis thaliana. We identified 94 putative stress-related miRNA genes, in which 8 miRNAs were new identified with stress-related response function based on targets prediction. Sequence analysis of these miRNA genes showed that most stress-related miRNAs possess TATA boxes in their promoters, and more than half contain at least two promoters. We also demonstrated that most stress-related miRNA genes contain stress-related elements in their promoters. Furthermore, conservation analysis showed that many stress-related miRNAs are species/family-specific and a subset of stress-related miRNAs may be derived from repeat sequences. Finally, we found that the stress-related miRNAs target 374 genes with 1,153 predicted target sites, of which 87.2% are targeted for gene cleavage and 12.8% affect protein translation. In conclusion, our findings provide an insight into both the function and evolution of stress-related miRNAs
Improved Cell Survival and Paracrine Capacity of Human Embryonic Stem Cell-Derived Mesenchymal Stem Cells Promote Therapeutic Potential for Pulmonary Arterial Hypertension.
Although transplantation of adult bone marrow mesenchymal stem cells (BM-MSCs) holds promise in the treatment for pulmonary arterial hypertension (PAH), the poor survival and differentiation potential of adult BM-MSCs have limited their therapeutic efficiency. Here, we compared the therapeutic efficacy of human embryonic stem cell-derived MSCs (hESC-MSCs) with adult BM-MSCs for the treatment of PAH in an animal model. One week following monocrotaline (MCT)-induced PAH, mice were randomly assigned to receive phosphate-buffered saline (MCT group); 3.0×106 human BM-derived MSCs (BM-MSCs group) or 3.0 ×106 hESC-derived MSCs (hESC-MSCs group) via tail vein injection. At 3 weeks posttransplantation, the right ventricular systolic pressure (RVSP), degree of RV hypertrophy, and medial wall thickening of pulmonary arteries were lower=, and pulmonary capillary density was higher in the hESC-MSC group as compared with BM-MSC and MCT groups (all p < 0.05). At 1 week posttransplantation, the number of engrafted MSCs in the lungs was found significantly higher in the hESC-MSC group than in the BM-MSC group (all p < 0.01). At 3 weeks posttransplantation, implanted BM-MSCs were undetectable whereas hESC-MSCs were not only engrafted in injured pulmonary arteries but had also undergone endothelial differentiation. In addition, protein profiling of hESC-MSC- and BM-MSC-conditioned medium revealed a differential paracrine capacity. Classification of these factors into bioprocesses revealed that secreted factors from hESC-MSCs were preferentially involved in early embryonic development and tissue differentiation, especially blood vessel morphogenesis. We concluded that improved cell survival and paracrine capacity of hESC-MSCs provide better therapeutic efficacy than BM-MSCs in the treatment for PAH. © 2012 Cognizant Comm. Corp.published_or_final_versio
Study on knowledge base verification based on Petri nets
The comparison of rule pairs is usually involved in traditional approaches to verify knowledge base. The efficiency of these approaches is low when used in the verification of large-scale knowledge base because of the comparison. An alternative method of detecting logical errors in knowledge base is presented in this paper. This is achieved by analyzing the reachability and the transition sequence of Petri nets which is the established model of rule base
Improved Cell Survival and Paracrine Capacity of Human Embryonic Stem Cell-Derived Mesenchymal Stem Cells Promote Therapeutic Potential for Pulmonary Arterial Hypertension.
Although transplantation of adult bone marrow mesenchymal stem cells (BM-MSCs) holds promise in the treatment for pulmonary arterial hypertension (PAH), the poor survival and differentiation potential of adult BM-MSCs have limited their therapeutic efficiency. Here, we compared the therapeutic efficacy of human embryonic stem cell-derived MSCs (hESC-MSCs) with adult BM-MSCs for the treatment of PAH in an animal model. One week following monocrotaline (MCT)-induced PAH, mice were randomly assigned to receive phosphate-buffered saline (MCT group); 3.0×106 human BM-derived MSCs (BM-MSCs group) or 3.0 ×106 hESC-derived MSCs (hESC-MSCs group) via tail vein injection. At 3 weeks posttransplantation, the right ventricular systolic pressure (RVSP), degree of RV hypertrophy, and medial wall thickening of pulmonary arteries were lower=, and pulmonary capillary density was higher in the hESC-MSC group as compared with BM-MSC and MCT groups (all p < 0.05). At 1 week posttransplantation, the number of engrafted MSCs in the lungs was found significantly higher in the hESC-MSC group than in the BM-MSC group (all p < 0.01). At 3 weeks posttransplantation, implanted BM-MSCs were undetectable whereas hESC-MSCs were not only engrafted in injured pulmonary arteries but had also undergone endothelial differentiation. In addition, protein profiling of hESC-MSC- and BM-MSC-conditioned medium revealed a differential paracrine capacity. Classification of these factors into bioprocesses revealed that secreted factors from hESC-MSCs were preferentially involved in early embryonic development and tissue differentiation, especially blood vessel morphogenesis. We concluded that improved cell survival and paracrine capacity of hESC-MSCs provide better therapeutic efficacy than BM-MSCs in the treatment for PAH. © 2012 Cognizant Comm. Corp.published_or_final_versio
Topological orbital ladders
We unveil a topological phase of interacting fermions on a two-leg ladder of
unequal parity orbitals, derived from the experimentally realized double-well
lattices by dimension reduction. topological invariant originates simply
from the staggered phases of -orbital quantum tunneling, requiring none of
the previously known mechanisms such as spin-orbit coupling or artificial gauge
field. Another unique feature is that upon crossing over to two dimensions with
coupled ladders, the edge modes from each ladder form a parity-protected flat
band at zero energy, opening the route to strongly correlated states controlled
by interactions. Experimental signatures are found in density correlations and
phase transitions to trivial band and Mott insulators.Comment: 12 pages, 5 figures, Revised title, abstract, and the discussion on
Majorana numbe
Improving the Feature Stability and Classification Performance of Bimodal Brain and Heart Biometrics
Electrical activities from brain (electroencephalogram, EEG) and heart (electrocardiogram, ECG) have been proposed as biometric modalities but the combined use of these signals appear not to have been studied thoroughly. Also, the feature stability of these signals has been a limiting factor for biometric usage. This paper presents results from a pilot study that reveal the combined use of brain and heart modalities provide improved classification performance and further-more, an improvement in the stability of the features over time through the use of binaural brain entrainment. The classification rate was increased, for the case of the neural network classifier from 92.4% to 95.1% and for the case of LDA, from 98.6% to 99.8%. The average standard deviation with binaural brain entrainment using all the inter-session features (from all the subjects) was 1.09, as compared to 1.26 without entrainment. This result suggests the improved stability of both the EEG and ECG features over time and hence resulting in higher classification performance. Overall, the results indicate that combining ECG and EEG gives improved classification performance and that through the use of binaural brain entrainment, both the ECG and EEG features are more stable over time
Strain engineering and one-dimensional organization of metal-insulator domains in single-crystal VO2 beams
Spatial phase inhomogeneity at the nano- to microscale is widely observed in
strongly-correlated electron materials. The underlying mechanism and
possibility of artificially controlling the phase inhomogeneity are still open
questions of critical importance for both the phase transition physics and
device applications. Lattice strain has been shown to cause the coexistence of
metallic and insulating phases in the Mott insulator VO2. By continuously
tuning strain over a wide range in single-crystal VO2 micro- and nanobeams,
here we demonstrate the nucleation and manipulation of one-dimensionally
ordered metal-insulator domain arrays along the beams. Mott transition is
achieved in these beams at room temperature by active control of strain. The
ability to engineer phase inhomogeneity with strain lends insight into
correlated electron materials in general, and opens opportunities for designing
and controlling the phase inhomogeneity of correlated electron materials for
micro- and nanoscale device applications.Comment: 14 pages, 4 figures, with supplementary informatio
A combination of left ventricular noncompaction and double orifice mitral valve
A 24-year-old woman admitted with mild chest distress associated with activity without chest complaint for twenty days. Two orifices were visible at the level of the mitral valve with a transthoracic short-axis view of the two-dimensional and three-dimensional echocardiography. The left ventricle was mildly dilatated and the left ventricular wall was thickened, especially at the apex and anterolateral wall, and appeared sponge-like. There were numerous, excessively prominent trabeculations associated with intertrabecular recesses. Although the coexistence of NVM and DOMV could be a coincidence, we believe that both defects were probably caused by a developmental arrest of the left ventricular myocardium in the present case
Spatial heterogeneity of habitat suitability for Rift Valley fever occurrence in Tanzania: an ecological niche modelling approach
Despite the long history of Rift Valley fever (RVF) in Tanzania, extent of its suitable habitat in the country remains unclear. In this study we investigated potential effects of temperature, precipitation, elevation, soil type, livestock density, rainfall pattern, proximity to wild animals, protected areas and forest on the habitat suitability for RVF occurrence in Tanzania. Presence-only records of 193 RVF outbreak locations from 1930 to 2007 together with potential predictor variables were used to model and map the suitable habitats for RVF occurrence using ecological niche modelling. Ground-truthing of the model outputs was conducted by comparing the levels of RVF virus specific antibodies in cattle, sheep and goats sampled from locations in Tanzania that presented different predicted habitat suitability values. Habitat suitability values for RVF occurrence were higher in the northern and central-eastern regions of Tanzania than the rest of the regions in the country. Soil type and precipitation of the wettest quarter contributed equally to habitat suitability (32.4% each), followed by livestock density (25.9%) and rainfall pattern (9.3%). Ground-truthing of model outputs revealed that the odds of an animal being seropositive for RVFV when sampled from areas predicted to be most suitable for RVF occurrence were twice the odds of an animal sampled from areas least suitable for RVF occurrence (95% CI: 1.43, 2.76, p < 0.001). The regions in the northern and central-eastern Tanzania were more suitable for RVF occurrence than the rest of the regions in the country. The modelled suitable habitat is characterised by impermeable soils, moderate precipitation in the wettest quarter, high livestock density and a bimodal rainfall pattern. The findings of this study should provide guidance for the design of appropriate RVF surveillance, prevention and control strategies which target areas with these characteristics
Biomass Smoke Exposure Is Associated With Gastric Cancer and Probably Mediated Via Oxidative Stress and DNA Damage: A Case-Control Study.
PURPOSE: We investigated the association between gastric cancer and environmental and dietary exposures. In addition, we explored probable mechanistic pathways for the influence of biomass smoke on gastric carcinogenesis. PATIENTS AND METHODS: The study was conducted in Lusaka, Zambia. Questionnaires were used to collect data on risk factors, whereas enzyme-linked immunosorbent assays and high-performance liquid chromatography were used to measure biologic exposures. Study data were analyzed using contingency tables and logistic regression. RESULTS: We enrolled 72 patients with gastric adenocarcinoma and 244 controls. Gastric cancer was positively associated with rural residence (odds ratio [OR], 2.9; 95% CI, 1.5 to 5.3), poverty (OR, 4.2; 95% CI, 1.9 to 9.1), and daily consumption of processed meat (OR, 6.4; 95% CI, 1.3 to 32) and negatively associated with consumption of green vegetables (OR, 0.2; 95% CI, 0.1 to 0.5). Gastric cancer was also associated with biomass smoke exposure (OR, 3.5; 95% CI, 1.9 to 6.2; P < .0001), an association that was stronger for intestinal-type cancers (OR, 3.6; 95% CI, 1.5 to 9.1; P = .003). Exposure to biomass smoke in controls was associated with higher urinary levels of 8-isoprostane (P < .0001), 8-hydroxydeoxyguanosine (P = .029), and 1-hydroxypyrene (P = .041). Gastric cancer was not associated with biochemical measures of current exposure to aflatoxins or ochratoxins. CONCLUSION: In Zambia, exposure to biomass smoke, daily consumption of processed meat, and poverty are risk factors for gastric cancer, whereas daily consumption of green vegetables is protective against gastric cancer. Exposure to biomass smoke was associated with evidence of oxidative stress and DNA damage, suggesting mechanistic plausibility for the observed association, and the association was restricted to intestinal-type gastric cancer
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