Browsing by Author "Yu, Hao"

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    Elevated carbon dioxide accelerates the spatial turnover of soil microbial communities
    (Wiley, 2016) Deng, Ye; He, Zhili; Xiong, Jinbo; Yu, Hao; Xu, Meiying; Hobbie, Sarah E; Reich, Peter B; Schadt, Christopher W; Kent, Angela; Pendall, Elise; Wallenstein, Matthew; Zhou, Jizhong
    Although elevated CO2 (eCO2) significantly affects the α-diversity, composition, function, interaction and dynamics of soil microbial communities at the local scale, little is known about eCO2 impacts on the geographic distribution of micro-organisms regionally or globally. Here, we examined the β-diversity of 110 soil microbial communities across six free air CO2 enrichment (FACE) experimental sites using a high-throughput functional gene array. The β-diversity of soil microbial communities was significantly (P < 0.05) correlated with geographic distance under both CO2 conditions, but declined significantly (P < 0.05) faster at eCO2 with a slope of −0.0250 than at ambient CO2 (aCO2) with a slope of −0.0231 although it varied within each individual site, indicating that the spatial turnover rate of soil microbial communities was accelerated under eCO2 at a larger geographic scale (e.g. regionally). Both distance and soil properties significantly (P < 0.05) contributed to the observed microbial β-diversity. This study provides new hypotheses for further understanding their assembly mechanisms that may be especially important as global CO2 continues to increase.
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    Topological field theory and quantum master equation in two dimensions.
    (2011-01) Yu, Hao
    In our thesis, I give the analogy of the main results in Kevin Costello's paper "The Gromov-Witten potential associated to a TCFT" for open-closed topological conformal field theory. In other words, I show that there is a Batalin-Vilkovisky algebraic structure on the open-closed moduli space (moduli space of Riemann surface with boundary and marked points) , which is defined by Harrelson, Voronov and Zuniga in "The open-closed moduli space and related algebraic structure", and the most important, there is a solution up to homotopy to the quantum master equation of that BV algebra, if the initial condition is given, under the assumption that a new geometric chain theory gives rise to ordinary homology. This solution is hoped to encode the fundamental chain of compactified open-closed moduli space, studied thoroughly by C.-C.Liu, as exactly in the closed case (Deligne-Mumford space in this case). We hope this result can give new insights to the mysterious two dimensional open-closed field theory.