Exploring the interaction between the human microbiota and infections

The microbiota is a living ecosystem that is influenced by a variety of host and environmental factors. Distinct microbiota colonizes various body sites, such as the gastrointestinal system and vaginal tract, corresponding to the unique microenvironment. A healthy gut microbiota contains a stable, balanced, and highly diverse reservoir of microbes. Commensal microorganisms co-evolved with the host have conferred pathogen colonization resistance. Lactobacillus species usually dominate the vaginal microbiota of majority healthy women. The vaginal microbiota has also been linked to sexually transmitted diseases, such as the human papillomavirus (HPV) infection. MicroRNA expression was found to be associated with microbiota composition. We studied the interactions of microbiota gut and vagina with metabolites, miRNA expression, and HPV infection in our investigations. In vitro three- dimensional (3D) cell-culture methods were also analyzed and developed for mechanistic investigations of the microbiota-host interaction. Study I is a cross-sectional study investigating the microbiota features in HPV-related diseases. We defined the HPV-related microbial composition in a high-vaccination coverage population of 345 young Swedish women. The associations of microbial composition and the infection of 27 HPV types were analyzed. HPV infection, especially for the infection of oncogenic HPV types, was characterized by a higher microbial alpha-diversity with non- Lactobacillus-dominant vaginal microbiota composition. The prevalence of bacterial vaginosis-associated bacteria (BV AB), Sneathia, Prevotella, and Megasphaera were significantly higher in women with HPV infection than in uninfected individuals. Study II investigated the associations among miRNA, HPV infection, and vaginal microbiota composition. A global miRNA expression increase was identified in non-Lactobacillus- dominate women compared with Lactobacillus-dominated women. The top two differently expressed miRNA, miR-23a-3p and miR-130a-3p, showed a prediction accuracy of > 97% for distinguishing Lactobacillus-dominated and non- Lactobacillus-dominated samples. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis of the target genes of miR-23a-3p and miR-130a-3p found that many pathways involved in cancer and infection were enriched, such as the mitogen-activated protein kinase (MAPK) signaling pathway, and the phosphatidylinositol 3-kinase (PI3K)-Akt signaling pathway. Study III explored the interactions between commensal bacteria and pathogens. We cocultured Salmonella with commensal bacteria isolations from an anaerobically cultivated human intestinal microflora (ACHIM). Commensal bacteria isolations belonging to the Clostridium and Eubacterium family showed significant inhibition of Salmonella growth. Following metabolite extraction and liquid chromatography-mass spectrometry analysis of the commensal bacteria and Salmonella metabolites in the coculture system of the commensal bacteria and Salmonella, adenine and adenosine were significantly higher in the coculture systems that inhibited Salmonella growth compared with the expressive systems. Functional assays of metabolite activity further validated the inhibition effect of adenine and adenosine on the growth of Salmonella and other antibiotic-resistant pathogens. Study IV established an anaerobic gut 3D model to study bacteria-host interactions. The Caco2 cells showed good cell viability and formed intestinal villi-like structures in our model. Anaerobic culture for 12 hours did not show a significant effect on the viability of cells, with only six genes differently expressed between cells cultured under anaerobic and aerobic conditions in RNA sequencing. RNA sequencing of Salmonella infected Caco2 cells cocultured in anaerobic conditions showed a large set of genes differentially expressed compared to aerobic conditions with the pathways associated with cell cycle, homologous recombination, and DNA replication. This supports our gut 3D model could be used for investigating host-microbe direct interactions under the anaerobic condition, which is essential for obligate anaerobic gut microbes

Ant Colony Algorithm and Simulation for Robust Airport Gate Assignment

Airport gate assignment is core task for airport ground operations. Due to the fact that the departure and arrival time of flights may be influenced by many random factors, the airport gate assignment scheme may encounter gate conflict and many other problems. This paper aims at finding a robust solution for airport gate assignment problem. A mixed integer model is proposed to formulate the problem, and colony algorithm is designed to solve this model. Simulation result shows that, in consideration of robustness, the ability of antidisturbance for airport gate assignment scheme has much improved

A Study of Molecular Interface of Grass-Herbivory Interaction in Grass

Grass-herbivore interaction is a complex process that involves wounding effects caused by herbivore feeding, defoliation effects due to leaf-surface loss during grazing, and the deposition of herbivore saliva onto the surface of plants (Chen et al., 2009). Wounding can stimulate plant growth but clearly differs from grazing (Mattiacci et al., 1995). Defoliation affects root development in grasses and alters the carbohydrate-metabolism pathway in rice. Saliva has been found to stimulate plant growth, enhance tiller and increase biomass. However, little is known about the molecular mechanisms of plant responses to grazing in molecular level. In our previous transcriptome studies, many genes relating with grazing were identified from sheepgrass (Li et al., 2013). In last IGC report, we proposed the concept of “molecular interface on grass-herbivore interaction” (Liu et al., 2013) to understand the interaction between plant and large herbivories on molecular level, which has significant importance on agriculture and grassland conservation. This paper will present some new results in the area

Heterogeneous Power-Splitting Based Two-Way DF Relaying with Non-Linear Energy Harvesting

Simultaneous wireless information and power transfer (SWIPT) has been recognized as a promising approach to improving the performance of energy constrained networks. In this paper, we investigate a SWIPT based three-step two-way decode-and-forward (DF) relay network with a non-linear energy harvester equipped at the relay. As most existing works require instantaneous channel state information (CSI) while CSI is not fully utilized when designing power splitting (PS) schemes, there exists an opportunity for enhancement by exploiting CSI for PS design. To this end, we propose a novel heterogeneous PS scheme, where the PS ratios are dynamically changed according to instantaneous channel gains. In particular, we derive the closed-form expressions of the optimal PS ratios to maximize the capacity of the investigated network and analyze the outage probability with the optimal dynamic PS ratios based on the non-linear energy harvesting (EH) model. The results provide valuable insights into the effect of various system parameters, such as transmit power of the source, source transmission rate, and source to relay distance on the performance of the investigated network. The results show that our proposed PS scheme outperforms the existing schemes.Comment: This article has been accepted by IEEE GLOBECOM201

Bovine serum albumin in saliva mediates grazing response in Leymus chinensis revealed by RNA sequencing

BACKGROUND: Sheepgrass (Leymus chinensis) is an important perennial forage grass across the Eurasian Steppe and is adaptable to various environmental conditions, but little is known about its molecular mechanism responding to grazing and BSA deposition. Because it has a large genome, RNA sequencing is expensive and impractical except for the next-generation sequencing (NGS) technology. RESULTS: In this study, NGS technology was employed to characterize de novo the transcriptome of sheepgrass after defoliation and grazing treatments and to identify differentially expressed genes (DEGs) responding to grazing and BSA deposition. We assembled more than 47 M high-quality reads into 120,426 contigs from seven sequenced libraries. Based on the assembled transcriptome, we detected 2,002 DEGs responding to BSA deposition during grazing. Enrichment analysis of Gene ontology (GO), EuKaryotic Orthologous Groups (KOG) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways revealed that the effects of grazing and BSA deposition involved more apoptosis and cell oxidative changes compared to defoliation. Analysis of DNA fragments, cell oxidative factors and the lengths of leaf scars after grazing provided physiological and morphological evidence that BSA deposition during grazing alters the oxidative and apoptotic status of cells. CONCLUSIONS: This research greatly enriches sheepgrass transcriptome resources and grazing-stress-related genes, helping us to better understand the molecular mechanism of grazing in sheepgrass. The grazing-stress-related genes and pathways will be a valuable resource for further gene-phenotype studies. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/1471-2164-15-1126) contains supplementary material, which is available to authorized users

Germplasm Evaluation of an Eurasia Steppe Native Specie--Sheepgrass (\u3cem\u3eLeymus chinensis\u3c/em\u3e)

Sheepgrass (Leymus chinensis (Trin.) Tzvel) is an advantageous perennial native grass in China and other northern Eurasian countries having steppe. As an important forage grass of great value in animal husbandry, sheepgrass is well known for its abundant foliage, high palatability and high nutritive content. Sheepgrass is also valuable in grassland restoration and conservation since it is a perennial grass with a rhizome network to fix the soil and can survive well in stressful environments. Terefore, the collection, evaluation and utilization of sheepgrass are necessary for protecting grassland biodiversity, for establishing artificial pasture, restoring degraded grassland, and the development of forage industry and animal husbandry in Eurasia’s native steppe. Here, we reviewed our previous studies on the collection, evaluation of phenotypic diversity for germplasm resources, distribution and domestication of wild sheepgrass, and application of sheepgrass new varieties

Discovery of entomopathogenic fungi across geographical regions in southern China on pine sawyer beetle Monochamus alternatus and implication for multi-pathogen vectoring potential of this beetle

Entomopathogen-based biocontrol is crucial for blocking the transmission of vector-borne diseases; however, few cross-latitudinal investigations of entomopathogens have been reported for vectors transmitting woody plant diseases in forest ecosystems. The pine sawyer beetle Monochamus alternatus is an important wood borer and a major vector transmitting pine wilt disease, facilitating invasion of the pinewood nematode Bursaphelenchus xylophilus (PWN) in China. Due to the limited geographical breadth of sampling regions, species diversity of fungal associates (especially entomopathogenic fungi) on M. alternatus adults and their potential ecological functions have been markedly underestimated. In this study, through traditional fungal isolation with morphological and molecular identification, 640 fungal strains (affiliated with 15 genera and 39 species) were isolated from 81 beetle cadavers covered by mycelia or those symptomatically alive across five regional populations of this pest in southern China. Multivariate analyses revealed significant differences in the fungal community composition among geographical populations of M. alternatus, presenting regionalized characteristics, whereas no significant differences were found in fungal composition between beetle genders or among body positions. Four region-representative fungi, namely, Lecanicillium attenuatum (Zhejiang), Aspergillus austwickii (Sichuan), Scopulariopsis alboflavescens (Fujian), and A. ruber (Guangxi), as well as the three fungal species Beauveria bassiana, Penicillium citrinum, and Trichoderma dorotheae, showed significantly stronger entomopathogenic activities than other fungi. Additionally, insect-parasitic entomopathogenic fungi (A. austwickii, B. bassiana, L. attenuatum, and S. alboflavescens) exhibited less to no obvious phytopathogenic activities on the host pine Pinus massoniana, whereas P. citrinum, Purpureocillium lilacinum, and certain species of Fusarium spp.—isolated from M. alternatus body surfaces—exhibited remarkably higher phytopathogenicity. Our results provide a broader view of the entomopathogenic fungal community on the vector beetle M. alternatus, some of which are reported for the first time on Monochamus spp. in China. Moreover, this beetle might be more highly-risk in pine forests than previously considered, as a potential multi-pathogen vector of both PWN and phytopathogenic fungi

Electrochemical deposition of Bi2Te3-based thin films

Conference Name:5th International Conference on Study of Matter at Extreme Conditions. Conference Address: Miami, FL. Time:MAR 28-APR 02, 2009.The electrochemical reduction processes on stainless-steel substrates from an aqueous electrolyte composed of nitric acid, Bi3+, HTeO2+, SbO+ and H2SeO3 systems were investigated using cyclic voltammetry. The thin films with a stoichiometry of Bi2Te3, Bi0.5Sb1.5Te3 and Bi2Te2.7Se0.3 have been prepared by electrochemical deposition at selected potentials. The structure, composition, and morphology of the films were studied by X-ray diffraction (XRD), environmental scanning electron microscopy (ESEM) and electron microprobe analysis (EMPA). The results showed that the films were single phase with the rhombohedral Bi2Te3 structure. The morphology and growth orientation of the films were dependent on the deposition potentials. (C) 2010 Elsevier Ltd. All rights reserved