821 research outputs found

    Comparison Analysis of Dust-Depressor Using Microbial Induced Carbonate Precipitation with Urease Reagent

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    The dust-depressors have been developed utilizing a method of microbial induced carbonate precipitation. This microbial dust-depressor has the characteristics of high efficiency for dust suppression and environmental protection. Optimal compositions of urease dust-depressor and microbial dust-depressor have been studied. In addition, pure water, CaCl2 and super absorbent polymer are chosen to compare with new dust-depressors on the performances. The results showed that the microbial dust-depressor had 3.13 mm/min of seepage velocity and 79.1% of dust suppression efficiency, which were superior to other dust-depressors on the performance of seepage velocity and dust suppression efficiency

    Comprehensive Evaluation of Wild \u3cem\u3eElymus\u3c/em\u3e L. Germplasm in Inner Mongolia

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    Grassland degradation is increasing in severity and is an important global issue in the 21st century. Increasing research is being conducted on how to solve these problems (Niu and Jiang 2004). Restoration and revegetation of degraded grassland and the establishment of artificial pastures are important in addressing degradation. Successful restoration requires the identification of species and seed sources that are adapted to the ecological conditions of the restoration site. Elymus L. is a large genus that contains about 150 species distributed across a wide range of ecological sites across temperate and subtropical regions of the world (Dewey 1984; Love 1984). There are at least 12 species in China (Guo 1987). Elymus includes many economically important forage grasses as well as species that possess useful genes for disease resistance, stress tolerance and adaptation, which can potentially be transferred to cereal crops through gene introgression. Species within Elymus have the potential for playing an important role in artificial pasture construction, grassland and animal husbandry development and ecological restoration. However, research is lacking on Chinese Elymus species, which can provide critical information for selecting suitable Elymus varieties and extending their use in China

    Increase in neuroexcitability of unmyelinated C-type vagal ganglion neurons during initial postnatal development of visceral afferent reflex functions

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    BACKGROUND: Baroreflex gain increase up closely to adult level during initial postnatal weeks, and any interruption within this period will increase the risk of cardiovascular problems in later of life span. We hypothesize that this short period after birth might be critical for postnatal development of vagal ganglion neurons (VGNs). METHODS: To evaluate neuroexcitability evidenced by discharge profiles and coordinate changes, ion currents were collected from identified A- and C-type VGNs at different developmental stages using whole-cell patch clamping. RESULTS: C-type VGNs underwent significant age-dependent transition from single action potential (AP) to repetitive discharge. The coordinate changes between TTX-S and TTX-R Na(+) currents were also confirmed and well simulated by computer modeling. Although 4-AP or iberiotoxin age dependently increased firing frequency, AP duration was prolonged in an opposite fashion, which paralleled well with postnatal changes in 4-AP- and iberiotoxin-sensitive K(+) current activity, whereas less developmental changes were verified in A-types. CONCLUSION: These data demonstrate for the first time that the neuroexcitability of C-type VGNs increases significantly compared with A-types within initial postnatal weeks evidenced by AP discharge profiles and coordinate ion channel changes, which explain, at least in part, that initial postnatal weeks may be crucial for ontogenesis in visceral afferent reflex function

    Gene Expression Divergence and Evolutionary Analysis of the Drosomycin Gene Family in Drosophila melanogaster

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    Drosomycin (Drs) encoding an inducible 44-residue antifungal peptide is clustered with six additional genes, Dro1, Dro2, Dro3, Dro4, Dro5, and Dro6, forming a multigene family on the 3L chromosome arm in Drosophila melanogaster. To get further insight into the regulation of each member of the drosomycin gene family, here we investigated gene expression patterns of this family by either microbe-free injury or microbial challenges using real time RT-PCR. The results indicated that among the seven drosomycin genes, Drs, Dro2, Dro3, Dro4, and Dro5 showed constitutive expressions. Three out of five, Dro2, Dro3, and Dro5, were able to be upregulated by simple injury. Interestingly, Drs is an only gene strongly upregulated when Drosophila was infected with microbes. In contrast to these five genes, Dro1 and Dro6 were not transcribed at all in either noninfected or infected flies. Furthermore, by 5′ rapid amplification of cDNA ends, two transcription start sites were identified in Drs and Dro2, and one in Dro3, Dro4, and Dro5. In addition, NF-κB binding sites were found in promoter regions of Drs, Dro2, Dro3, and Dro5, indicating the importance of NF-κB binding sites for the inducibility of drosomycin genes. Based on the analyses of flanking sequences of each gene in D. melanogaster and phylogenetic relationship of drosomycins in D. melanogaster species-group, we concluded that gene duplications were involved in the formation of the drosomycin gene family. The possible evolutionary fates of drosomycin genes were discussed according to the combining analysis of gene expression pattern, gene structure, and functional divergence of these genes

    Application of Local Wave Decomposition in Seismic Signal Processing

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    Local wave decomposition (LWD) method plays an important role in seismic signal processing for its superiority in significantly revealing the frequency content of a seismic signal changes with time variation. The LWD method is an effective way to decompose a seismic signal into several individual components. Each component represents a harmonic signal localized in time, with slowly varying amplitudes and frequencies, potentially highlighting different geologic and stratigraphic information. Empirical mode decomposition (EMD), the synchrosqueezing transform (SST), and variational mode decomposition (VMD) are three typical LWD methods. We mainly study the application of the LWD method especially EMD, SST, and VMD in seismic signal processing including seismic signal de‐noising, edge detection of seismic images, and recovery of the target reflection near coal seams

    Systematic cloning and analysis of autophagy-related genes from the silkworm Bombyx mori

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    <p>Abstract</p> <p>Background</p> <p>Through the whole life of eukaryotes, autophagy plays an important role in various biological events including development, differentiation and determination of lifespan. A full set of genes and their encoded proteins of this evolutionarily conserved pathway have been identified in many eukaryotic organisms from yeast to mammals. However, this pathway in the insect model organism, the silkworm <it>Bombyx mori</it>, remains poorly investigated.</p> <p>Results</p> <p>Based on the autophagy pathway in several model organisms and a series of bioinformatic analyses, we have found more than 20 autophagy-related genes from the current database of the silkworm <it>Bombyx mori</it>. These genes could be further classified into the signal transduction pathway and two ubiquitin-like pathways. Using the mRNA extracted from the silkgland, we cloned the full length cDNA fragments of some key genes via reverse transcription PCR and 3' rapid amplification of cDNA ends (RACE). In addition, we found that the transcription levels of two indicator genes <it>BmATG8 </it>and <it>BmATG12 </it>in the silkgland tend to be increased from 1<sup>st </sup>to 8<sup>th </sup>day of the fifth instar larvae.</p> <p>Conclusion</p> <p>Bioinformatics in combination with RT-PCR enable us to remodel a preliminary pathway of autophagy in the silkworm. Amplification and cloning of most autophagy-related genes from the silkgland indicated autophagy is indeed an activated process. Furthermore, the time-course transcriptional profiles of <it>BmATG8 </it>and <it>BmATG12 </it>revealed that both genes are up-regulated along the maturation of the silkgland during the fifth instar. These findings suggest that the autophagy should play an important role in <it>Bombyx mori </it>silkgland.</p

    Epidemiologic characterization of 30 confirmed cases of human infection with avian influenza A(H7N9) virus in Hangzhou, China

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    BACKGROUND: We examined the clinical and epidemiological characteristics of 30 cases of human infection with avian influenza A(H7N9) virus in Hangzhou and investigated their external environments to provide evidence for contact tracing and disease prevention and control. METHODS: The cases confirmed from April 1 through May 1, 2013 were studied. Field epidemiologic surveys were conducted to collect the clinical and epidemiologic data. Case-related and environmental specimens were collected for etiologic detection. RESULTS: Thirty cases of human infection with avian influenza A(H7N9) virus were confirmed in Hangzhou from April 1 through May 1, 2013, including one pregnant woman and three deaths. The median age of the patients was 62 years (range: 38–86 years). Twenty-three of the patients were men (76.67%). The median duration between disease onset and occurrence of respiratory failure and confirmed diagnosis was 5 and 6 days, respectively. Maximum medical observation of 666 close contacts of the patients revealed no irregularity. Of 314 external environmental specimens, the overall positive detection rate of H7N9 nucleic acid was 28.98%. Eight districts of Hangzhou city had positive detections in the external environments, the highest rate being in Yuhang District (78.13%). Statistical analysis of the specimen collection locations indicates a significant difference between the case-linked locations and the non-case locations (χ( 2 ) = 16.563, p < 0.05) in terms of H7N9 viral nucleic acid detection rate. No epidemiologic link has been found among the 30 cases. CONCLUSIONS: Most of the infected were retired individuals aged 60 years or older. Men made the majority. The cases are sporadic at present, with no evidence of human-to-human transmission. Exposures to poultry and live poultry markets may be important sources of infection
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