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The ecological suitability of marine resources and environmental conditions for marine ranching in Guangdong, South China was evaluated. Niche theory was used to establish an ecological suitability evaluation model for marine ranching site selection, and suitability evaluation of marine ranching was conducted in. Results show that the ecological suitability index of marine ranching site selection was greater than 64.0 in 20 sites, including offshore Shantou Bay, offshore Zhanjiang Port, and Longdou Bay etc., which are the priority areas for marine ranching. In other 13 sites, the ecological suitability index ranged between 8.0 and 32.0, including Houjiang Bay, Haimen Bay, and Jieshi Bay etc., indicating the suitability for marine ranching. However, the ecological suitability index was 0 in Shantou Bay, Zhujiang (Pearl) River estuary, Huangmao Sea, Guanghai Bay, Zhanjiang Port, Qiongzhou Strait, and Anpu Port. These sites are thus unsuitable for marine ranching. This study provides a theoretical basis for site selection and planning of marine ranching in Guangdong Province. [ABSTRACT FROM AUTHOR]

Replacing natural gas with the environmentally sustainable biogas is a promising way to reduce the usage of fossil fuels and promote organic waste utilization. Micro gas turbine (MGT), as a common power supply machine, is capable of adopting biogas as the fuel. Given the different intrinsic components between natural gas and biogas, combustion performance of biogas in MGT was studied in this work. The effects of fuel composition and excess air coefficient on combustion performance were analyzed through three-dimensional numerical simulation of the MGT combustor. RNG k-ε turbulent model, eddy-dissipation/finite rate model, and eight-step reaction mechanism were adopted in the simulation. The results showed that when the CO2 percentage in biogas increases, the NO and CO emissions decreases. However, the fuel rate and pressure drop of combustion chamber increases to maintain constant thermal input. The overall high velocity also increases the requirement for materials of combustion chamber. Furthermore, the average temperature of whole combustor decreases when the excess air coefficient increases. Accordingly, the CO2 mole fraction in biogas should be controlled below 30% and the optimal range of the excess air coefficient is 2–2.5 for the MGT. [ABSTRACT FROM AUTHOR]

Seagrass meadows constitute a prestigious ecosystem in the marine environment, providing valuable ecological and commercial services. Among the various causes, pollutions are considered one of the significant reasons for seagrass decline globally. This study investigates the impacts of polycyclic aromatic hydrocarbons mixture (pyrene, phenanthrene, and fluorene) on bacterial communities in Halophila ovalis sediments. The seagrass sediment bacterial microbiome was evaluated in a batch culture experiment by Illumina MiSeq sequencing. Culture-able bacterial strains were isolated and characterized by 16S rRNA gene sequencing. The results demonstrated an excellent alpha diversity in the original sediments with a Shannon index of (8.078) compared to the subsequent control group (5.908) and PAH-treated group (PAH-T) (4.916). Three phyla, Proteobacteria, Firmicutes, and Bacteroidetes, were detected in high abundance in the control and PAH-T groups. However, a significant difference (P < 0.05) was observed at the genus level between control and PAH-T group bacterial consortia. Pseudomonas, Mycobacterium, Idiomarina, Hydrogenophaga, Alteromonas, Sphingobacterium, and several others were highly abundant in PAH-T groups. Most of the culture-able isolates recovered in this study showed the closest resemblance to previously identified hydrocarbon-degrading bacteria. Among the three strains, Mix-16 (Citricoccus yambaruensis) and Mix-20 (Gordonia rubripertincta) showed a higher degradation of PAHs than Mix-19 (Isoptericola halotolerans) in the monoculture experiment. The most increased degradation of PAHs was recorded in the co-culture experiment. The present work revealed that PAHs could act as environmental stress and can influence bacterial community succession. Moreover, the co-culture strategy significantly enhanced the biodegradation of PAHs. [ABSTRACT FROM AUTHOR]

Seagrass ecosystems are among the most productive marine ecosystems, and diazotrophic communities play a crucial role in sustaining the productivity and stability of such ecosystems by introducing fixed nitrogen. However, information concerning both total and active diazotrophic groups existing in different compartments of seagrass is lacking. This study comprehensively investigated the diversity, structure, and abundance of diazotrophic communities in different parts of the seagrass Halophila ovalis at the DNA and RNA level from clone libraries and real-time quantitative PCR. Our results indicated that nearly one-third of existing nitrogen-fixing bacteria were active, and their abundance might be controlled by nitrogen to phosphorus ratio (N:P). Deltaproteobacteria and Gammaproteobacteria were dominant groups among the total and active diazotrophic communities in all samples. These two groups accounted for 82.21% and 70.96% at the DNA and RNA levels, respectively. The genus Pseudomonas and sulfate-reducing bacteria (genera: Desulfosarcina, Desulfobulbus, Desulfocapsa, and Desulfopila) constituted the significant fraction of nitrogen-fixing bacteria in the seagrass ecosystem, playing an additional role in denitrification and sulfate reduction, respectively. Moreover, the abundance of the nitrogenase gene, nifH, was highest in seawater and lowest in rhizosphere sediments from all samples. This study highlighted the role of diazotropic communities in the subtropical seagrass ecosystem. [ABSTRACT FROM AUTHOR]

Seagrass meadows are one of the most important marine ecosystems. Alkanes are the common hydrocarbon contaminants that can affect seagrass growth. In this study, a large spatial-scale investigation has been carried out on the alkane-degrading bacterial community structure in the rhizosphere and non-rhizosphere sediments of two seagrass species (Thalassia hemprichii and Halophila ovalis). AlkB gene was employed as a biomarker gene to study the alkane-degrading bacterial community structure. The results showed that the alpha diversity of the alkane-degrading bacterial community in T. hemprichii non-rhizosphere sediments was higher than that of its rhizosphere sediments. However, the alpha diversity of the alkane-degrading bacterial community in H. ovalis rhizosphere sediments was higher than that of its non-rhizosphere sediments in the open sea, but the result was contrast in the coast area. In addition, the alpha diversity of alkane-degrading bacterial communities in the coast area was higher than that of far away from the coast in the T. hemprichii rhizosphere and non-rhizosphere sediments. The phylogenetic analysis result revealed that the alkB sequences from the seagrass ecosystem were mainly affiliated with the class Alphaproteobacteria, and had the two novel lineages. Genus Agrobacterium was the most predominant alkane-degrading bacteria. These results contributed to disclose the geographical distribution pattern of alkane-degrading bacteria in the seagrass ecosystem of the South China Sea. [ABSTRACT FROM AUTHOR]

Seagrass meadows have seriously deteriorated in recent years. Seagrass associated phytate-mineralizing rhizobacteria potentially have functions related to seagrass nutrition, health and sustainable growth. The β-propeller phytases (BPPs) are the only phytase family in aquatic environments, but there are few studies on the BPP community structure of seagrass. In this study, clone libraries and quantitative PCR (qPCR) assays were used to compare the diversity and abundances of the BPP communities of Halodule endl, Halophila ovalis and Thalassia hemprichii in Xisha and Sanya, and to investigate the distribution characteristics of BPP genes in the rhizosphere sediment, which provedes insight into species specialty from phytic mineralization in subtropical and tropical seagrass ecosystems. The highest diversity of BPP genes was found for Thalassia hemprichii in Sanya Bay. Thalassia hemprichii in Sanya had higher abundances of BPPs, which were linked to Gammaproteobacteria. The BPP community diversity and OTUs of Thalassia hemprichii in Sanya were much higher than those of Thalassia hemprichii on Yongxing Island and Stone Island. The seagrass BPP communities had higher diversity and evenness from sampling sites with more human activity. The qPCR results showed that the abundance of phytate acid-degradating bacteria was approximately three times larger in Thalassia hemprichii rhizosphere sediment samples than in Halodule endl and Halophila ovalis rhizosphere sediment samples. This study highlighted that the diversity and abundances of bacteria genetically encoding BPP in the rhizosphere of Thalassia hemprichii were clearly higher than those of Halodule endl and Halophila ovalis. Further study of microbial phosphorus cycling will provide new insights into seagrass meadow ecosystems. [ABSTRACT FROM AUTHOR]

Polycyclic aromatic hydrocarbons (PAHs), originating from anthropogenic and natural sources, are highly concerned environmental pollutants. This study investigated the impact of two model PAHs (pyrene and phenanthrene) on bacterial community succession in the seagrass meadows sediment in a lab-scale microcosm. Halophila ovalis sediment slurry microcosms were established, one group was placed as a control, and the other two were treated with pyrene and phenanthrene. Bacterial community succession in response to respective PAHs was investigated by 16S rRNA amplicon sequencing. The results demonstrated that bacterial diversity decrease in each microcosm during the incubation process; however, the composition of bacterial communities in each microcosm was significantly different. Proteobacteria (37–89%), Firmicutes (9–41%), and Bacteroides (7–21%) were the predominant group at the phylum levels. Their abundance varies during the incubation process. Several previously reported hydrocarbon-degrading genera, such as Pseudomonas, Spinghobium, Sphingobacterium, Mycobacterium, Pseudoxanthomonas, Idiomarina, Stenotrophomonas, were detected in higher abundance in pyrene- and phenanthrene-treated microcosms. However, these genera were distinctly distributed in the pyrene and phenanthrene treatments, suggesting that certain bacterial groups favorably degrade different PAHs. Statistical analyses, such as ANOSIM and PERMANOVA, also revealed that significant differences existed among the treatments' bacterial consortia (P < 0.05). This work showed that polycyclic aromatic hydrocarbon significantly affects bacterial community succession, and different PAHs might influence the bacterial community succession differently. [ABSTRACT FROM AUTHOR]

Seagrass meadows are vital ecosystems with high productivity and biodiversity and often in the oligotrophic area. Nitrogen usually limits productivity in this ecosystem as the main nutrient factor. Biological nitrogen fixation by diazotrophs in the rhizosphere sediment can introduce "new" nitrogen into the ecosystem. Previous studies revealed that most sulfate-reducing bacteria (SRB) can also fix nitrogen like the nitrogen-fixing bacteria (NFB). Moreover, both sulfate reduction and nitrogen fixation were affected by the organic pollutant. However, rare information is available regarding the NFB and SRB community composition and their temporal response to the pollutant. The quantitative real-time polymerase chain reaction and polymerase chain reaction denaturing gradient gel electrophoresis have been used to analyze NFB and SRB communities' shifts under different PAHs concentrations. They both experienced a dramatic shift under PAHs stress but exhibited different patterns. SRB could use the low and high concentration PAHs at the early stage of the incubation, while only the low concentration of PAHs could stimulate the growth of NFB through the whole incubation period. The predominant species of NFB communities were Alphaproteobacteria, Gammaproteobacteria, and Deltaproteobacteria; while for SRB communities were class Epsilonproteobacteria. Redundancy analysis indicated the significant environmental factors for the two communities were both ammonium and pH (P < 0.05). There existed nifH sequences related to known nitrogen fixing SRB Desulfatibacillum alkenivorans, which confirmed that microbial N2 fixation and sulfate reduction were coupled in the seagrass ecosystem by molecular technique. Our investigation provides new insight into the NFB and SRB community in the seagrass meadow. [ABSTRACT FROM AUTHOR]

Seagrasses constitute a significant part of coral reef ecosystems, representing high primary productivity and one of the most important coastal habitats in marine ecosystems. Though seagrasses possess irreplaceable ecological services to the marine environment, taxonomical ambiguity still exists due to similar morphological characters and phenotypic plasticity. As an emerging technology, DNA barcoding can effectively identify cryptic species using a short orthologous DNA region. In this study, we collected samples from five different locations (Daya Bay, Xincun Bay, Sanya Bay, Xisha Islands, and Nansha Islands), and three seagrass species Cymodocea rotundata, Thalassia hemprichii and Halophila ovalis was evaluated. Moreover, ITS, matK and rbcL genes were used as DNA barcodes. The results indicated that single ITS and concatenated ITS/matK/rbcL both conducted better species resolution than single matK and rbcL. Nevertheless, single ITS was more convenient. Furthermore, in all the four topology trees, three species resolved as 3 clusters as well H. ovalis and T. hemprichii grouped as sister clade. In the meantime, differentiation lay in intra-species based on the result of single ITS and three-locus analysis. Within H. ovalis and T. hemprichii separately, individuals from Xisha Islands first group together, then grouped with individuals from Nansha Islands and/or Xincun Bay and/or Sanya Bay and/or Daya Bay, which indicated that geographical distribution influenced population evolution. However, intra-species differentiation did not emerge in the tree of matK or rbcL. [ABSTRACT FROM AUTHOR]

The community structure of coral associated microorganisms will change greatly in coral bleaching. However, the relationship between specific bacteria groups and Symbiodinium, which is easy to be found in the bleaching process, has been ignored for a long time. In this study, the changes of coral microbial community during a natural bleaching event in the South China Sea were studied by 16S rRNA gene high-throughput sequencing. The microbial community composition of bleached corals was significantly different from that of normal corals (P < 0.001). OTUs belong to Bacillus, Exiguobacterium, Oceanobacillus, Saccharibacteria and Ostreobiaceae was significantly increased in the bleaching corals. The relative abundance of 30.9% OTUS changed significantly during coral bleaching. The relative abundance of potential coral pathogenic groups was not significantly different between normal and bleaching corals. Symbiodinium positively correlated bacterial groups accounted for 6.9% and 4.3% in the normal corals and bleached corals, respectively. The dominated groups of potential Symbiodinium-partner bacteria are Lactococcus and Bacillus. The potential Symbiodinium-partner bacterial groups in bleached corals were significantly lower than that in the normal corals, which further showed their coexistence with Symbiodinium. This study provides insight into the role of potential Symbiodinium-partner bacterial groups in the coral bleaching process and supports the theory of beneficial microorganisms for corals. [ABSTRACT FROM AUTHOR]

Rhizosphere microbes are crucial to seagrass meadows because they promote plant growth and heath. However, information concerning the response of rhizosphere microorganisms in seagrass sediment in the presence of different nitrogen sources is lacking. Here, by means of high-throughput sequencing, we investigated how addition of inorganic nitrogen affects the rhizosphere microbiome of the tropical seagrass Thalassia hemperichii. A seagrass culture system was set up to conduct a nitrogen addition (ammonium and nitrate) simulation experiment. We found that the relative abundance of Proteobacteria and Bacteroidetes was increased in inorganic nitrogen-enriched samples, whereas that of Acidobacteria decreased under ammonium enrichment, especially after 35 days. High levels of inorganic nitrogen addition caused a significant decrease in the relative abundance of Desulfobacteraceae, Sulfurovaceae, and Spirochaetes, which are primarily involved in sulfur cycling. Additionally, the abundance of microbes in the seagrass rhizosphere reached the highest after the ammonium-enrichment treatment. Among the analyzed seagrass photosynthetic characteristics, seagrass leaves presented the highest light utility in treatments receiving nitrate, followed by the control groups and ammonium-enrichment groups. Moreover, 16S rRNA gene-predicted functional analysis suggested that some functions related to metabolism of amino acids and signal transduction were enriched in samples receiving high ammonium, whereas nitrate addition enriched predicted functions related to diseases. These findings provide new insights into the response of microbial communities to different types of nitrogen additions in seagrass ecosystems. [ABSTRACT FROM AUTHOR]

Performance of CeO-LaO/ZSM-5 sorbents for sulfur removal was examined at temperature ranging from 500 oC to 700 oC. The sulfur capacity of 5Ce5La/ZSM-5 was much bigger than that of CeO/ZSM-5. H had a negative impact on the sulfidation; however, CO had little influence on sulfur removal. The characterization results showed that CeO and LaO were well dispersed on ZSM-5 because of the intimate admixing of LaO and CeO, the major sulfidation products were CeOS and LaOS, the XRD and SEM results revealed that ZSM-5 structure could remain intact during preparation and sulfidation process, the H-TPR showed that the reducibility of CeO can be remarkably enhanced by addition of La. [ABSTRACT FROM AUTHOR]

Perovskite LaMnO/ZSM-5 was used for reactive adsorption of hydrogen sulfide at 500-700 °C. The sorbents showed good desulphurization performance, the highest sulfur capacity of 1020 µmol S/g over 5La5Mn/ZSM-5 was obtained at 600 °C. The reducing gases (H and CO) can obviously shorten the breakthrough time and reduce the sulfur capacity. Incorporating Mn ions into LaO lattice improved the sulfidation activity due to the formation of perovskite LaMnO with good reducibility and structure stability. [ABSTRACT FROM AUTHOR]

In order to improve the safety management of urban gas transmission and distribution system, failure mode and effects analysis (FMEA) was used to construct the reliability analysis system of the pipeline network. To solve the problem of subjectivity and uncertainty of the multi-expert decision making, the correlation operator was introduced into the calculation of the risk priority number (RPN). Using FMEA along with weight analysis and expert investigation approach, the FMEA evaluation table was given, including five failure modes, risk priority numbers, failure causes and effects, as well as corrective actions. The results show that correlation operator can directly process the linguistic terms and quantify the priority of the risks. [ABSTRACT FROM AUTHOR]

Polymorphisms of the XPC gene have been reported to be associated with an increased risk of head and neck cancer (HNC), though the exact biological effect is still unclear. Genetic association studies (GAS) investigating the associations between three common polymorphisms (PAT, Lys939Gln, and Ala499Val) of the XPC gene and HNC risk have produced contradictory and inconclusive results. The aim of this meta-analysis is to evaluate the contributions of these polymorphisms to the risk of HNC. A literature search was conducted in the PubMed, Embase, Web of Science, Cochrane Library, and China National Knowledge Infrastructure databases to indentify eligible studies. Pooled odds ratios (ORs) and 95 % confidence intervals (95 % CIs) were used to evaluate the strength of the associations under a fixed- or random-effect model according to heterogeneity test. Twelve case-control studies were included in this meta-analysis with a total of 3,078 HNC patients and 4,311 healthy controls. For XPC PAT, a significant overall association was found under all major genetic models. Stratified analyses further indicated significant associations in the Caucasian, population-based, non-PCR-RFLP, esophageal cancer and oral cancer subgroups. For XPC Lys939Gln, few significant results were found in either the overall analysis or stratified analyses. For XPC Ala499Val, the combined results revealed a significantly increased risk of HNC for carriers of the 499Val allele. This meta-analysis shows that the XPC PAT and Ala499Val polymorphisms may be associated with an increased risk of HNC, while XPC Lys939Gln may not be associated with HNC risk. Despite some limitations, this meta-analysis establishes solid statistical evidence for an association between XPC genetic polymorphisms and HNC risk that warrants further validation. [ABSTRACT FROM AUTHOR]

The three-dimensional heat transfer and thermal stress of a steel cooling stave in a blast furnace at Maanshan Iron and Steel Co. Ltd. are built. The temperature and thermal stress fields of cooling stave are calculated by using finite element method software ANSYS. The results show the rise in maximum temperature and thermal stress of the stave hot surface is not high when cooling pipe is replaced by cooling elliptical tube. Because of the decrease in the cross-sectional area for cooling elliptical tube, the thickness of the cooling stave is reduced and cooling water flow is saved. As a result, the iron-making cost can be reduced. [ABSTRACT FROM AUTHOR]

Focuses on Wlbachia, a maternally inherited intracellular bacterium, which can infect arthropods. Association with a risk for cytoplasmic incompatibility (CI), parthenogenesis, the feminization of genetic males, and male-killing in different hosts; Investigation into the molecular mechanisms by which this bacterium causes reproductive abnormalities; Cloning and characterization of the gene encoding phage-related tail protein (PrTP) from Wolbachia in Drosophila melanogaster Cantons (wMelCS) and from Wolbachia in Drosophila melanogaster yw67c23 (wMel); Use of representational difference analysis (RDA) and ligation-mediated PCR (LM-PCR); Testing of the functionality of a bipartite nuclear localization signal sequence (NLS) in Drosophila S2 cells; Examination of PrTP expression in various strains of Wolbachia; Suggestion that PrTP has an indirect role in inducing CI; Assertion that the existence of prtp shows direct evidence of phage-mediated horizontal gene transfer (HGT) that might be linked to a variety of reproductive abnormalities of Wolbachia.

ADAM family plays important roles in neurogenesis. The cytoplasmic tail of ADAM19 (ADAM19-CT) contains 193 residues. The presence of two putative SH3 ligand-bianding sites suggests potential interactions with cytosolic proteins, which could be possibly linked to the functions of ADAM19. To address these issues, a yeast two-hybrid screen was performed in human fetal brain cDNA library to isolate proteins that interact with the cytoplasmic tail of ADAM19. Four proteins were obtained, ArgBP1, β-cop, ubiquitin and a novel protein. GST-Pulldown assay has confirmed the interaction between AdAM19 and ArgBP1. By constructing series of deletion mutants of ADAM19-CT and ArgBP1 respectively, the interaction regions have been identified. They are the SH3 binding sites in ADAM19-CT and the P4 region in ArgBP1. And the interaction is specific. ArgBP1 does not bind to ADAM22, ADAM29 or ADAM9 (mouse). ArgBP1may be the key protein, which accounts for the physiological function of ADAM19. [ABSTRACT FROM AUTHOR]

Studies the association of serum and glucocorticoid-inducible kinase (SGK) and 14-3-3 theta protein in serine/threonine phosphorylation mechanism for thrombopoietin/MPl signal transduction. Administration of yeast two-hybrid screening; Isolation of positive clones from independent transformants; Interaction between SGK and 14-3-3 protein.

Thrombopoietin (TPO) is the major cytokine involved in platelet production and exerts its effects via the receptor c-Mpl. The yeast two-hybrid system has been used to screen the proteins interacting with c-Mpl. First, the cDNA fragment of c-Mpl intracellular domain was cloned into two-hybrid vector pAS2, and the resulting plasmid is designated as pASMM. Then a human placenta cDNA library was screened using the pASMM as a target plasmid. Seven positive clones were isolated from 150 000 independent transformants. Sequence analysis of one of the positive clones demonstrates that a part of coding sequence of vimentin from 611 bp to 3′ end and flanking non-translation region was obtained. Therefore, there is an interaction between vimentin and TPO receptor. The results suggest that cytoskeletal protein may play an important role in TPO signal transduction pathway. [ABSTRACT FROM AUTHOR]