AcoMYB4, an Ananas comosus L. MYB transcription factor, functions in osmotic stress through negative regulation of ABA signaling

Drought and salt stress are the main environmental cues affecting the survival, development, distribution, and yield of crops worldwide. MYB transcription factors play a crucial role in plants’ biological processes, but the function of pineapple MYB genes is still obscure. In this study, one of the pineapple MYB transcription factors, AcoMYB4, was isolated and characterized. The results showed that AcoMYB4 is localized in the cell nucleus, and its expression is induced by low temperature, drought, salt stress, and hormonal stimulation, especially by abscisic acid (ABA). Overexpression of AcoMYB4 in rice and Arabidopsis enhanced plant sensitivity to osmotic stress; it led to an increase in the number stomata on leaf surfaces and lower germination rate under salt and drought stress. Furthermore, in AcoMYB4 OE lines, the membrane oxidation index, free proline, and soluble sugar contents were decreased. In contrast, electrolyte leakage and malondialdehyde (MDA) content increased significantly due to membrane injury, indicating higher sensitivity to drought and salinity stresses. Besides the above, both the expression level and activities of several antioxidant enzymes were decreased, indicating lower antioxidant activity in AcoMYB4 transgenic plants. Moreover, under osmotic stress, overexpression of AcoMYB4 inhibited ABA biosynthesis through a decrease in the transcription of genes responsible for ABA synthesis (ABA1 and ABA2) and ABA signal transduction factor ABI5. These results suggest that AcoMYB4 negatively regulates osmotic stress by attenuating cellular ABA biosynthesis and signal transduction pathways

Investigation of cleat and micro-fracture and its aperture distribution in the coals of different ranks in North China: Relative to reservoir permeability

The apertures of cleats and micro-fractures in coal play an important role in the permeability of the coal bed. In this study, optical microscopy and scanning electron microscopy were used to investigate the morphology of cleats and micro-fractures and their apertures, distribution of minerals, and matrix/fracture interactions. The neighboring mineralized and unmineralized cleats suggest the possibility of multi-stage evolutionary processes of cleat formation during the coalification process. The micro-fracture distribution of coals is closely related to their components, including organic macerals and inorganic minerals. Micro-fractures are prone to developing at the junction surface of organic macerals or the surface of organic and inorganic minerals. A mineral-genetic micro-fracture can be classified as an intra-crystal micro-fracture, an extra-crystal micro-scale fracture, or a grain-edge micro-scale fracture. Compared with the low- and middle-ranking coals, cleat and micro-scale fractures in high-ranking coal are usually filled with carbonate minerals and clay minerals. Statistical analysis reveals that the aperture distribution of cleat and micro-fracture in coal shows a log-normal distribution. The aperture of cleat and micro-fracture shows a decreasing trend with increase in coal rank. For low-ranking coal, cleats contribute more to the permeability than micro-fractures. However, for the middle- and high-ranking coals, the contribution of cleats and micro-fractures to the coal reservoir permeability will be close. As the rank of coal increases, the degree of cleat contribution to reservoir permeability decreases, while the degree of micro-fracture contributing to the reservoir permeability increases. Possible reasons for the extremely low reservoir permeability in China may be the following: 1) subsurface cleats and micro-fractures close their apertures significantly due to the in situ geo-stress or 2) cleats and micro-fractures have better permeability in the geological history, which makes the precipitation of minerals decrease the coal reservoir permeability. Therefore, the acid solvent (e.g., HAc, HCl, and HF) added to the drilling or hydraulic fracturing fluid or the geo-stress relief technologies may be an effective way of enlarging the cleat or micro-fracture aperture and enhance the reservoir permeability for coalbed methane production

High circulating CD39+ regulatory T cells predict poor survival for sepsis patients

SummaryBackgroundSepsis encompasses two phases, the ‘hyper’-reactive phase and the ‘hypo’-reactive phase. The initial inflammatory stage is quickly counterbalanced by an anti-inflammatory response, which compromises the immune system, leading to immune suppression. Regulatory T cells (Tregs) have been implicated in the pathogenesis of sepsis by inducing immunosuppression; however, the role of CD39+ Tregs in the process of sepsis is uncertain. This study investigated the dynamic levels of CD39+ Tregs and their phenotypic change in sepsis.MethodsFourteen patients with systemic inflammatory response syndrome (SIRS), 42 patients with sepsis, and 14 healthy controls were enrolled. Sequential blood samples were used to analyze the numbers of CD39+ Tregs and their phenotypic changes. Survival at 28 days was used to evaluate the capacity of CD39+ Treg levels to predict mortality in sepsis patients.ResultsSepsis patients displayed a high percentage (3.13%, 1.46%, and 0.35%, respectively) and mean fluorescence intensity (MFI) (59.65, 29.7, and 24.3, respectively) of CD39+ Tregs compared with SIRS patients and healthy subjects. High-level expression of CD39+ Tregs was correlated with the severity of sepsis, which was reflected by the sepsis-related organ failure assessment score (r=0.322 and r=0.31, respectively). In addition, the expression of CD39+ Tregs was associated with survival of sepsis patients (p<0.01). By receiver-operating characteristic (ROC) curve analysis, the percentage and MFI of CD39+ Tregs showed similar sensitivities and specificities to predict mortality (74.2% and 85.1%, and 73.9% and 84.1%, respectively). Using Kaplan–Meier curves to assess the impact of CD39+ Tregs percentage and MFI on overall survival, we found that a high CD39+ Tregs percentage (p<0.001; >4.1%) and MFI (p<0.001; >49.2) were significantly associated with mortality. Phenotypically, CD39+ Tregs from sepsis patients showed high expression of CD38 and PD-1 (p<0.01 and p<0.01 respectively).ConclusionsIncreased expression of CD39+ Tregs was associated with a poor prognosis for sepsis patients, which suggests that CD39+ Treg levels could be used as a biomarker to predict the outcome of sepsis patients

Poly(diallyldimethylammonium-MoS4) based amorphous molybdenum sulphide composite for selectively mercury uptake from wastewater across a large pH region

Amorphous molybdenum sulphide materials are attracting more attention in heterogeneous catalysis, gas adsorption and water remediation fields. Herein, a new type of amorphous molybdenum sulphide composite (poly(diallyldimethylammonium-MoS), shorten as PDADMA-MoS) was synthesized via a facile precipitation reaction. Metal adsorption tests of prepared PDADMA-MoS composite shows that Hg and Pb concentrations in solution can decrease from 10 ppm t

Performance Analysis of Multi-Channel DCA MAC protocol in Cognitive Wireless Mesh Networks

Conference Name:WRI International Conference on Communications and Mobile Computing. Conference Address: Kunming, PEOPLES R CHINA. Time:JAN 06-08, 2009.The spectrum resource gets scared with the development of wireless communication. Users in cognitive wireless mesh network need to switch among multi-channels to communicate. In this paper, we propose a mathematical model of multi-channel DCA protocol in cognitive wireless mesh network. This model is based on Bernoulli and M/M/K queuing model. From the validation by compare simulation with analytical result, we con see our model and analysis is simple and accurate

Engineering anion resin based amorphous molybdenum sulphide composite for treatment of authentic acid mine drainage

Acid mine drainage (AMD) is an acidic effluent containing many toxic heavy metal ions (e.g. Cu2+, Cd2+, Hg2+) in mining industry, leading to serious environmental issues such as natural soil and aquatic pollution that threats the whole ecosystem and biosafety. Conventional neutralization and precipitation process cannot effectively remove heavy metal ions due to the risk of secondary contamination. Herein, we report an engineered amorphous molybdenum sulphide composite for selective removal of heavy metal ions from other co-existing ions in AMD solution. This composite was prepared by a facile ion exchange reaction, in which tetrathiomolybdate (MoS42-) anions are firmly bonded to strong anion exchange resins by replacing chloride ions. The obtained composite was used to remove heavy metal ions from both synthetic and authentic AMD solution. The results of batch and fixed-bed column tests suggest high selectivity towards heavy metals, fast adsorption kinetics, good reusability and excellent adsorption capacities in the order of Hg(II)>>Pb(II)>Cu(II)>Cd(II). The adsorption data are fitted well by Langmuir model, indicating the single-layer adsorption mechanism. The theoretical adsorption capacities calculated by Langmuir model are 259.0 mg/g for Cu(II), 204.1 mg/g for Cd(II), 495.0 mg/g for Pb(II) and 1538.4 mg/g for Hg(II). The interaction between metal ions (Cu, Cd, Pb, Hg) and MoS42- anions are demonstrated by the formation of Mo-S-metal (Cu, Cd, Pb, Hg) bonding (the red shift of S2p peak in XPS spectra). Our results support the potential practical application of this new material for scavenging heavy metal ions in AMD wastewater

Molybdenum sulphide modified chelating resin for toxic metal adsorption from acid mine wastewater

Acid mine wastewater from mining industries leads to serious environmental problems due to its acidic nature and high levels of hazardous heavy metal ions. Thus, it is important to develop novel adsorbent materials for selective removing heavy metal ions. In this work, an amorphous molybdenum sulphide functionalized dipicolyamine exchanger were prepared and ultilised to scavenge toxic heavy metal ions from both synthetic and real acid mine waste water (copper mining industry). This new exchanger combines the advantages of exceptional heavy metal affinities from molybdenum sulphide and engineered macroporous structure from dipicolylamine resin. The results of batch and fixed-bed column tests suggest high selectivity towards heavy metals, fast adsorption kinetics, good reusability and excellent adsorption capacities in the sequence of Hg(II)≫Cd(II) > Cu(II). The metal adsorption mechanism has been demonstrated by X-ray Photoelectron Spectroscopy (XPS). Our findings support the potential practical application of this new material for scavenging heavy metal ions in mining wastewater

Efficient Algorithm for Constructing Order K Voronoi Diagrams in Road Networks

The order k Voronoi diagram (OkVD) is an effective geometric construction to partition the geographical space into a set of Voronoi regions such that all locations within a Voronoi region share the same k nearest points of interest (POIs). Despite the broad applications of OkVD in various geographical analysis, few efficient algorithms have been proposed to construct OkVD in real road networks. This study proposes a novel algorithm consisting of two stages. In the first stage, a new one-to-all k shortest path finding procedure is proposed to efficiently determine the shortest paths to k nearest POIs for each node. In the second stage, a new recursive procedure is introduced to effectively divide boundary links within different Voronoi regions using the hierarchical tessellation property of the OkVD. To demonstrate the applicability of the proposed OkVD construction algorithm, a case study of place-based accessibility evaluation is carried out. Computational experiments are also conducted on five real road networks with different sizes, and results show that the proposed OkVD algorithm performed significantly better than state-of-the-art algorithms

Key Technologies in the Design of a Vacuum Die Casting Mould for Aluminum Alloy Joints

Conference Name:International Conference on Manufacturing Science and Engineering (ICMSE 2009). Conference Address: Zhuhai, PEOPLES R CHINA. Time:DEC 26-28, 2009.Aluminum alloy joints are a key component of a light-weight bus body, hence, they have a complicated structure and high strength requirement. A vacuum die casting mould has been developed and joints have been manufactured using a CAE simulation, a "whole-process-vacuum exhaust" vacuum die casting process and a decreased cross-section design for vacuum-pumping. The joint's internal porosity has been noticeably reduced and its mechanical properties have been considerably improved in comparison with joints manufactured from die casting

Reference Gene Selection for qRT-PCR Normalization Analysis in kenaf (Hibiscus cannabinus L.) under Abiotic Stress and Hormonal Stimuli

Kenaf (Hibiscus cannabinus L.), an environmental friendly and economic fiber crop, has a certain tolerance to abiotic stresses. Identification of reliable reference genes for transcript normalization of stress responsive genes expression by quantitative real-time PCR (qRT-PCR) is important for exploring the molecular mechanisms of plants response to abiotic stresses. In this study, nine candidate reference genes were cloned, and their expression stabilities were assessed in 132 abiotic stress and hormonal stimuli samples of kenaf using geNorm, NormFinder, and BestKeeper algorithms. Results revealed that HcPP2A (Protein phosphatase 2A) and HcACT7 (Actin 7) were the optimum reference genes across all samples; HcUBC (Ubiquitin-conjugating enzyme like protein) was the worst reference gene for transcript normalization. The reliability of the selected reference genes was further confirmed by evaluating the expression profile of HcWRKY28 gene at different stress durations. This work will benefit future studies on discovery of stress-tolerance genes and stress-signaling pathways in this important fiber crop