Browsing by Author "Li, Ying"

Now showing 1 - 8 of 8
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    Biochemical and Microscopic Characterization of INFT-1: an Inverted Formin in C. elegans
    Li, Ying (Virginia Tech, 2011-03-14)
    Formins are potent regulators of actin dynamics that can remodel the actin cytoskeleton to control cell shape, cell cytokinesis, and cell morphogenesis. The defining feature of formins is the formin homology 2 (FH2) domain (Paul and Pollard, 2008), which promotes actin filament assembly while processively moving along the polymerizing filament barbed end. INFT-1 is one of six formin family members present in Caenorhabditis elegans (Hunt-Newbury et al., 2007) and is most closely related to vertebrate INF2, an inverted formin with regulatory domains in the C- rather than N-terminus. Nematode INFT-1 contains both formin homology 1 (FH1) and formin homology 2 (FH2) domains. However, it does not share the regulatory N-terminal Diaphanous Inhibitory Domain (DID) domain and C-terminal Diaphanous Autoregulatory Domain (DAD) domain found in mammalian INF2. In contrast to mammalian INF2, the sequence of INFT-1 starts immediately at FH1 domain and C-terminal region of INFT-1 shares little homology with INF2, suggesting that elegans INFT-1 is regulated by other mechanisms. We used fluorescence spectroscopy to determine the effect of INFT-1 FH1FH2 on actin assembly and total internal reflection fluorescence microscopy to investigate how INFT-1 formin homology 1 and formin homology 2 domains (FH1FH2) mediate filament nucleation and elongation. INFT-1 FH1FH2 nucleates actin filament and promote actin assembly. However, INFT-1 FH1FH2 reduces filament barbed-end elongation rates in the absence or presence of profilin. Evidences demonstrated that INFT-1 is non-processive, indicating a unique mechanism of nucleation. INFT-1 nucleation efficiency is similar to the efficiency of Arabidopsis FORMIN1 (AFH1), another non-processive formin. High phosphate affected the assembly activity of INFT-1 FH1FH2 in the absence or presence of profilin. INFT is thus the second example of a non-processive formin member and will allow a more detailed understanding of the mechanistic difference between processive and non-processive formins.
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    Construction of Reference Chromosome-Scale Pseudomolecules for Potato: Integrating the Potato Genome with Genetic and Physical Maps
    Sharma, Sanjeev Kumar; Bolser, Daniel; de Boer, Jan; Sonderkaer, Mads; Amoros, Walter; Carboni, Martin Federico; D'Ambrosio, Juan Martin; de la Cruz, German; Di Genova, Alex; Douches, David S.; Eguiluz, Maria; Guo, Xiao; Guzman, Frank; Hackett, Christine A.; Hamilton, John P.; Li, Guangcun; Li, Ying; Lozano, Roberto; Maass, Alejandro; Marshall, David; Martinez, Diana; McLean, Karen; Mejia, Nilo; Milne, Linda; Munive, Susan; Nagy, Istvan; Ponce, Olga; Ramirez, Manuel; Simon, Reinhard; Thomson, Susan J.; Torres, Yerisf; Waugh, Robbie; Zhang, Zhonghua; Huang, Sanwen; Visser, Richard G. F.; Bachem, Christian W. B.; Sagredo, Boris; Feingold, Sergio E.; Orjeda, Gisella; Veilleux, Richard E.; Bonierbale, Merideth; Jacobs, Jeanne M. E.; Milbourne, Dan; Martin, David Michael Alan; Bryan, Glenn J. (Genetics Society of America, 2013-11)
    The genome of potato, a major global food crop, was recently sequenced. The work presented here details the integration of the potato reference genome (DM) with a new sequence-tagged site marker-based linkage map and other physical and genetic maps of potato and the closely related species tomato. Primary anchoring of the DM genome assembly was accomplished by the use of a diploid segregating population, which was genotyped with several types of molecular genetic markers to construct a new similar to 936 cM linkage map comprising 2469 marker loci. In silico anchoring approaches used genetic and physical maps from the diploid potato genotype RH89-039-16 (RH) and tomato. This combined approach has allowed 951 superscaffolds to be ordered into pseudomolecules corresponding to the 12 potato chromosomes. These pseudomolecules represent 674 Mb (similar to 93%) of the 723 Mb genome assembly and 37,482 (similar to 96%) of the 39,031 predicted genes. The superscaffold order and orientation within the pseudomolecules are closely collinear with independently constructed high density linkage maps. Comparisons between marker distribution and physical location reveal regions of greater and lesser recombination, as well as regions exhibiting significant segregation distortion. The work presented here has led to a greatly improved ordering of the potato reference genome superscaffolds into chromosomal pseudomolecules.
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    Digital Mix Design for Performance Optimization of Asphalt Mixture
    Li, Ying (Virginia Tech, 2015-03-27)
    Asphalt mix design includes the determination of a gradation, asphalt content, other volumetric properties, the evaluation of mechanical properties and moisture damage potentials. In this study, a computational method is developed to aid mix design. Discrete element method (DEM) was used to simulate the formation of skeleton and voids structures of asphalt concrete of different gradations of aggregates. The optimum gradation could be determined by manipulating the particle locations and orientations and placing smaller particles in the voids among larger particles. This method aims at an optimum gradation, which has been achieved through experimental methods. However, this method takes the mechanical properties or performance of the mixture into consideration, such as inter-aggregate contacts and local stability. A simple visco-elastic model was applied to model the contacts between asphalt binder and aggregates. The surface texture of an aggregate particle can be taken into consideration in the inter-particle contact model. The void content before compactions was used to judge the relative merits of a gradation. Once a gradation is selected, the Voids in Mineral Aggregate (VMA) can be determined. For a certain air void content, the mastics volume or the binder volume or the asphalt content can be determined via a digital compression test. The surface area of all the aggregates and the film thickness can be then calculated. The asphalt content can also be determined using an alternative approach that is based on modeling the inter-particle contact with an asphalt binder layer. In this study, considering the necessity of preservation of the compaction temperature, the effect of various temperatures on Hot Mix Asphalt (HMA) samples properties has been evaluated. As well, to evaluate the effect of this parameter on different grading, two different grading have been used and samples were compacted at various temperatures. Air voids also influence pore water pressure and shrinkage of asphalt binder and mixture significantly. The shrinkage is measured on a digital model that represents beams in a steel mold and is defined as the linear autogenous deformation at horizontal direction.
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    Digitalization and network capability as enablers of business model innovation and sustainability performance: The moderating effect of environmental dynamism
    Li, Ying; Cui, Li; Wu, Lin; Lowry, Paul Benjamin; Kumar, Ajay; Tan, Kim Hua (2023)
    In the face of relentless global competition and regulatory pressures, the imperative for firms to digitally transform has become critical. This is particularly salient for Chinese manufacturing firms as they strive for sustainability, a multidimensional construct comprising both economic and environmental performance. Leveraging dynamic capabilities theory, this study aims to unravel the intricate interplay between digitalization, network capability, business model innovation (BMI), and environmental dynamism in shaping a firm’s sustainability performance. Our research is driven by a compelling question: How do digitalization and network capabilities impact firms’ sustainability performance, and what roles do BMI and environmental dynamism play in this relationship? To answer this question, we employed a robust survey-based methodology encompassing 1,600 Chinese manufacturing firms, yielding 255 completed and validated responses. The findings reveal that network capability mediates the influence of digitalization on two types of BMI—novelty-centered and efficiency-centered. Further, these forms of BMI act as mediators between digitalization and network capability, and the two dimensions of sustainability: economic and environmental performance. Notably, environmental dynamism serves as a double-edged sword. It negatively moderates the impact of digitalization on efficiency-centered BMI, but positively moderates the influence of network capability on the same. Our study offers nuanced theoretical and practical implications. It extends dynamic capabilities theory by elucidating how digital and network capabilities can be leveraged for sustainable outcomes via business model innovation. Moreover, the research provides managerial insights, particularly for Chinese manufacturing firms, on navigating the complex landscape of digital transformation toward sustainability. Considering these insights, we recommend that firms prioritize network capabilities and strategically innovate their business models to harness the full potential of digital transformation. Simultaneously, organizations should be cognizant of the environmental dynamism within which they operate, as it can both hinder and enable their journey toward sustainability.
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    Enhanced disinfection of Escherichia coli and bacteriophage MS2 in water using a copper and silver loaded titanium dioxide nanowire membrane
    Rao, Guiying; Brastad, Kristen S.; Zhang, Qianyi; Robinson, Rebecca; He, Zhen; Li, Ying (2016-08-01)
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    Error statistics and scalability of quantum error mitigation formulas
    Qin, Dayue; Chen, Yanzhu; Li, Ying (Nature Portfolio, 2023-04)
    Quantum computing promises advantages over classical computing in many problems. Nevertheless, noise in quantum devices prevents most quantum algorithms from achieving the quantum advantage. Quantum error mitigation provides a variety of protocols to handle such noise using minimal qubit resources. While some of those protocols have been implemented in experiments for a few qubits, it remains unclear whether error mitigation will be effective in quantum circuits with tens to hundreds of qubits. In this paper, we apply statistics principles to quantum error mitigation and analyse the scaling behaviour of its intrinsic error. We find that the error increases linearly O(epsilon N) with the gate number N before mitigation and sublinearly O(epsilon'N-gamma) after mitigation, where gamma approximate to 0.5, epsilon is the error rate of a quantum gate, and epsilon' is a protocol-dependent factor. The root N scaling is a consequence of the law of large numbers, and it indicates that error mitigation can suppress the error by a larger factor in larger circuits. We propose the importance Clifford sampling as a key technique for error mitigation in large circuits to obtain this result.
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    A meta-analysis of 1,119 manipulative experiments on terrestrial carbon-cycling responses to global change
    Song, Jian; Wan, Shiqiang; Piao, Shilong; Knapp, Alan K.; Classen, Aimee T.; Vicca, Sara; Ciais, Philippe; Hovenden, Mark J.; Leuzinger, Sebastian; Beier, Claus; Kardol, Paul; Xia, Jianyang; Liu, Qiang; Ru, Jingyi; Zhou, Zhenxing; Luo, Yiqi; Guo, Dali; Langley, J. Adam; Zscheischler, Jakob; Dukes, Jeffrey S.; Tang, Jianwu; Chen, Jiquan; Hofmockel, Kirsten S.; Kueppers, Lara M.; Rustad, Lindsey E.; Liu, Lingli; Smith, Melinda D.; Templer, Pamela H.; Thomas, R. Quinn; Norby, Richard J.; Phillips, Richard P.; Niu, Shuli; Fatichi, Simone; Wang, Yingping; Shao, Pengshuai; Han, Hongyan; Wang, Dandan; Lei, Lingjie; Wang, Jiali; Li, Xiaona; Zhang, Qian; Li, Xiaoming; Su, Fanglong; Liu, Bin; Yang, Fan; Ma, Gaigai; Li, Guoyong; Liu, Yanchun; Liu, Yinzhan; Yang, Zhongling; Zhang, Kesheng; Miao, Yuan; Hu, Mengjun; Yan, Chuang; Zhang, Ang; Zhong, Mingxing; Hui, Yan; Li, Ying; Zheng, Mengmei (2019-09)
    Direct quantification of terrestrial biosphere responses to global change is crucial for projections of future climate change in Earth system models. Here, we synthesized ecosystem carbon-cycling data from 1,119 experiments performed over the past four decades concerning changes in temperature, precipitation, CO2 and nitrogen across major terrestrial vegetation types of the world. Most experiments manipulated single rather than multiple global change drivers in temperate ecosystems of the USA, Europe and China. The magnitudes of warming and elevated CO2 treatments were consistent with the ranges of future projections, whereas those of precipitation changes and nitrogen inputs often exceeded the projected ranges. Increases in global change drivers consistently accelerated, but decreased precipitation slowed down carbon-cycle processes. Nonlinear (including synergistic and antagonistic) effects among global change drivers were rare. Belowground carbon allocation responded negatively to increased precipitation and nitrogen addition and positively to decreased precipitation and elevated CO2. The sensitivities of carbon variables to multiple global change drivers depended on the background climate and ecosystem condition, suggesting that Earth system models should be evaluated using site-specific conditions for best uses of this large dataset. Together, this synthesis underscores an urgent need to explore the interactions among multiple global change drivers in under-represented regions such as semi-arid ecosystems, forests in the tropics and subtropics, and Arctic tundra when forecasting future terrestrial carbon-climate feedback.
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    Rural Income and Wealth Inequality in China: A Study of Anhui and Sichuan Provinces, 1994-1995
    Li, Ying (Virginia Tech, 2000-06-12)
    China has been experiencing a great transition from a socialist collective economy to a market economy since 1978. Before the transition started, the Communist Party had established a socialist collective system with very low levels of income and wealth inequality. With the deepening of the rural reform and the development of rural industry, a large number of people were lifted out of poverty. However, as the people's living standards are rising, disparities in income and wealth are also being accentuated. This thesis's main purpose is to study the extent and determinants of income and wealth inequality in rural China. Based on a sample survey data from Anhui and Sichuan provinces, the thesis answers the following five questions: 1. How much income and wealth inequality is there in rural China in 1994-1995? 2. How has inequality in rural China changed since the reform of 1978? 3. How do the components of income and wealth in China affect the income and wealth distributions? 4. What social and economic factors are most responsible for influencing income and wealth in rural China? 5. How much of the inequality in income and wealth can be accounted for by the factors that predict income and wealth? The main findings of the study are, first, rural income inequality was low in the two provinces in 1994-1995 and wealth inequality was higher than income inequality. Second, in the industrialized Sichuan province, nonagricultural income made a big contribution to income inequality, while in the agricultural Anhui province, agricultural income played an important role in increasing income inequality. Third, education, good land, sufficient labor, and better communication resources are positively related to income and wealth.