Browsing by Author "Li, Ying"
Now showing 1 - 10 of 10
Results Per Page
Sort Options
Item Open Access Acquisition of Chinese characters: the effects of character properties and individual differences among second language learners.(Frontiers in psychology, 2015-01) Kuo, Li-Jen; Kim, Tae-Jin; Yang, Xinyuan; Li, Huiwen; Liu, Yan; Wang, Haixia; Hyun Park, Jeong; Li, YingIn light of the dramatic growth of Chinese learners worldwide and a need for cross-linguistic research on Chinese literacy development, this study drew upon theories of visual complexity effect (Su and Samuels, 2010) and dual-coding processing (Sadoski and Paivio, 2013) and investigated (a) the effects of character properties (i.e., visual complexity and radical presence) on character acquisition and (b) the relationship between individual learner differences in radical awareness and character acquisition. Participants included adolescent English-speaking beginning learners of Chinese in the U.S. Following Kuo et al. (2014), a novel character acquisition task was used to investigate the process of acquiring the meaning of new characters. Results showed that (a) characters with radicals and with less visual complexity were easier to acquire than characters without radicals and with greater visual complexity; and (b) individual differences in radical awareness were associated with the acquisition of all types of characters, but the association was more pronounced with the acquisition of characters with radicals. Theoretical and practical implications of the findings were discussed.Item Open Access Challenges facing translational research organizations in China: a qualitative multiple case study.(Journal of translational medicine, 2013-10) Zhou, Laixin; Li, Ying; Bosworth, Hayden B; Ehiri, John; Luo, ChangkunBackground
Translational medicine is attracting much attention worldwide and many translational research organizations (TROs) have been established. In China, translational medicine has developed rapidly, but faces many challenges. This study was aimed at exploring these challenges faced by emerging TROs in China.Method
A qualitative, multiple case study approach was used to assess the challenges faced by TROs in China. Data were collected between May and August 2012.Results
Eight cases were identified. Overall, four themes that characterized TROs in China emerged from analyses: 1. objectives, organizer, and funding resources, 2. participating partners and research teams, 3. management, and 4. achievements. All TROs had objectives related to translating basic discovery to clinic treatment and cultivating translational researchers. In terms of organizer and funding resources, 7 out of 8 TROs were launched only by universities and/or hospitals, and funded mostly through research grants. As for participating partners and multidisciplinary research teams, all but one of the TROs only involved biomedical research institutions who were interested in translational research, and characterized as clinical research centers; 7 out of 8 TROs involved only researchers from biomedicine and clinical disciplines and none involved disciplines related to education, ethnicity, and sociology, or engaged the community. Current management of the TROs were generally nested within the traditional research management paradigms, and failed to adapt to the tenets of translational research. Half of the TROs were at developmental stages defined as infrastructure construction and recruitment of translational researchers.Conclusions
TROs in China face the challenge of attracting sustainable funding sources, widening multidisciplinary cooperation, cultivating multi-disciplinary translational researchers and adapting current research management to translational research. Greater emphasis should be placed on increasing multidisciplinary cooperation, and innovating in education programs to cultivate of translational researchers. Efforts should be made to reform research management in TROs, and establish sustainable funding resources.Item Open Access Chinese Seniors’ Leisure Participation and Constraints in Five Cities(Asian Social Science) Li, Ying; Luo, Baozhen; Huang, Chenchen; Wu, JunminLeisure participation plays an important role in healthy aging. With the increasing elderly population and its potential social and economic influences, examining the factors that contribute to leisure constraints can be meaningful in evaluating and shaping Chinese seniors’ leisure participation. Adopting a face-to-face cross-sectional design, this study interviewed 907 community-dwelling seniors in five cities across Eastern, Western, and Southeastern China to explore their leisure comprehension, participation, perceived constraints, and the relationship between demographic factors and perceived constraints. The results indicated that the participants were satisfied with their leisure participation in general; their leisure comprehension and participation were consistent with the literature. Various demographic factors influenced the perception of leisure constraints differently, with the city size of the participants’ residence standing out in terms of its impact on the number of constraints. Recommendations for future research and policy development to promote healthy aging are discussed.Item Open Access Essays in Industrial Organization(2015) Li, YingThis dissertation consists of three chapters investigating the effect of firms' entry and exit behavior on market outcomes. Chapters 1 and 2 relate to the recent financial crisis in the auto industry that led to General Motor and Chrysler's bankruptcy filing and their dealer network reconstruction, studying firms and consumers' response to this industry shock. Chapter 3 challenges the current merger policy by proposing a selective entry mechanism.
The first chapter examines the impact of new car dealer closures on surviving dealers' profitability and consumer welfare during General Motor and Chrysler's bankruptcy restructuring. Using a complete sample of new car transaction data from 2007 to 2013 in Iowa, I estimate the effect of changes in dealer networks on surviving dealers' sales, prices, and consumer welfare by building a structural model with spatial differentiation and conducting counterfactual analysis. I further estimate this effect by conducting retrospective analysis. These two methods are compared, and the results validate the assumptions of the structural model.
The second chapter empirically investigates the effect of financial distress on used car prices and sales. When purchasing durable goods such as cars, consumers are expected to respond to the likelihood of default for auto makers because it will affect the provision of warranty and future maintenance service, as well as availability of parts. I find that a 10% increase in the likelihood of bankruptcy results in a $86 price drop in used cars. Sales drops only for used cars with remaining warranty and those sold by franchised dealers. These results imply that consumers do respond to auto makers' financial distress, which could add an additional cost to the existing financial problem faced by auto makers.
The third chapter is co-authored with Dr. Andrew Sweeting and Dr. James Roberts and looks at potential entry defense. Horizontal mergers may be approved if antitrust authorities believe that new entry would limit any anticompetitive effects. This `potential entry defense' has led to mergers being approved in concentrated markets in several industries, including airlines. However, entry will be both less likely and less able to constrain market power if the pre-merger entry process already selected the best firms into the market, for example those firms with better product qualities or lower marginal or fixed costs. We estimate a rich empirical entry model allowing for these types of selection using data from airline routes connecting the top 80 airports by enplanement. Our results indicate that selection is important and helps to explain the fact that airline mergers have tended to increase prices without inducing a significant number of new entering firms, even though most of these markets have several potential entrants and, in most cities, entry barriers are relatively low. We also use our model to conduct counterfactual merger analysis.
Item Open Access Exploring the Perceptions of Local Citizens towards the Hangzhou Trap-Neuter-Release (TNR) Program and its Outcomes(2023-05-02) Li, YingThis paper highlights the issue of a large number of stray cats in China and emphasizes the need for proper intervention to prevent further problems. The Trap-Neuter-Return (TNR) program policy has been implemented in many countries to control the overpopulation of stray cats, which has proven to be effective. However, in China, the TNR program has only been implemented in a few mega-cities such as Beijing, Shanghai, Shenzhen, and others. The purpose of this paper is to investigate the perspectives of local citizens on the Hangzhou TNR program, including its necessity and results. To achieve this, surveys and qualitative interviews were conducted to capture the viewpoints of both supporters and opponents of the program. The research collected information from a diverse group of citizens to gain a comprehensive understanding of public attitudes towards the TNR program for the stray cat community. Surveys are particularly valuable in providing insights into public perceptions and support for the program. They can reveal people's knowledge and experiences with stray cats, their assessment of the effectiveness of the TNR program, their level of support for the program, and their recommendations for improving it. Interviews were also conducted with local animal protection non-governmental organizations (NGOs), hospital directors, and relevant businesspersons to gain insight into their knowledge of the TNR program. Additionally, a survey was conducted to gather data on local citizens' perceptions and attitudes toward stray cats and the TNR program. The collected data were analyzed to evaluate the effectiveness of the TNR program in reducing the number of stray cats in Hangzhou, China, while considering and improving the current dilemma.Item Open Access Impact of Community-Based DOT on Tuberculosis Treatment Outcomes: A Systematic Review and Meta-Analysis.(PLoS One, 2016) Zhang, HaiYang; Ehiri, John; Yang, Huan; Tang, Shenglan; Li, YingBACKGROUND: Poor adherence to tuberculosis (TB) treatment can lead to prolonged infectivity and poor treatment outcomes. Directly observed treatment (DOT) seeks to improve adherence to TB treatment by observing patients while they take their anti-TB medication. Although community-based DOT (CB-DOT) programs have been widely studied and promoted, their effectiveness has been inconsistent. The aim of this study was to critical appraise and summarize evidence of the effects of CB-DOT on TB treatment outcomes. METHODS: Studies published up to the end of February 2015 were identified from three major international literature databases: Medline/PubMed, EBSCO, and EMBASE. Unpublished data from the grey literature were identified through Google and Google Scholar searches. RESULTS: Seventeen studies involving 12,839 pulmonary TB patients (PTB) in eight randomized controlled trials (RCTs) and nine cohort studies from 12 countries met the criteria for inclusion in this review and 14 studies were included in meta-analysis. Compared with clinic-based DOT, pooled results of RCTs for all PTB cases (including smear-negative or -positive, new or retreated TB cases) and smear-positive PTB cases indicated that CB-DOT promoted successful treatment [pooled RRs (95%CIs): 1.11 (1.02-1.19) for all PTB cases and 1.11 (1.02-1.19) for smear-positive PTB cases], and completed treatment [pooled RRs (95%CIs): 1.74(1.05, 2.90) for all PTB cases and 2.22(1.16, 4.23) for smear-positive PTB cases], reduced death [pooled RRs (95%CIs): 0.44 (0.26-0.72) for all PTB cases and 0.39 (0.23-0.66) for smear-positive PTB cases], and transfer out [pooled RRs (95%CIs): 0.37 (0.23-0.61) for all PTB cases and 0.42 (0.25-0.70) for smear-positive PTB cases]. Pooled results of all studies (RCTs and cohort studies) with all PTB cases demonstrated that CB-DOT promoted successful treatment [pooled RR (95%CI): 1.13 (1.03-1.24)] and curative treatment [pooled RR (95%CI): 1.24 (1.04-1.48)] compared with self-administered treatment. CONCLUSIONS: CB-DOT did improved TB treatment outcomes according to the pooled results of included studies in this review. Studies on strategies for implementation of patient-centered and community-centered CB-DOT deserve further attention.Item Open Access Neuron-specific SUMO knockdown suppresses global gene expression response and worsens functional outcome after transient forebrain ischemia in mice.(Neuroscience, 2017-02) Zhang, Lin; Liu, Xiaozhi; Sheng, Huaxin; Liu, Shuai; Li, Ying; Zhao, Julia Q; Warner, David S; Paschen, Wulf; Yang, WeiSmall ubiquitin-like modifier (SUMO) conjugation (SUMOylation) plays key roles in neurologic function in health and disease. Neuronal SUMOylation is essential for emotionality and cognition, and this pathway is dramatically activated in post-ischemic neurons, a neuroprotective response to ischemia. It is also known from cell culture studies that SUMOylation modulates gene expression. However, it remains unknown how SUMOylation regulates neuronal gene expression in vivo, in the physiologic state and after ischemia, and modulates post-ischemic recovery of neurologic function. To address these important questions, we used a SUMO1-3 knockdown (SUMO-KD) mouse in which a Thy-1 promoter drives expression of 3 distinct microRNAs against SUMO1-3 to silence SUMO expression specifically in neurons. Wild-type and SUMO-KD mice were subjected to transient forebrain ischemia. Microarray analysis was performed in hippocampal CA1 samples, and neurologic function was evaluated. SUMOylation had opposite effects on neuronal gene expression before and after ischemia. In the physiological state, most genes regulated by SUMOylation were up-regulated in SUMO-KD compared to wild-type mice. Brain ischemia/reperfusion significantly modulated the expression levels of more than 400 genes in wild-type mice, with a majority of those genes upregulated. The extent of this post-ischemic transcriptome change was suppressed in SUMO-KD mice. Moreover, SUMO-KD mice exhibited significantly worse functional outcome. This suggests that suppression of global gene expression response in post-ischemic brain due to SUMO knockdown has a negative effect on post-ischemic neurologic function. Together, our data provide a basis for future studies to mechanistically link SUMOylation to neurologic function in health and disease.Item Open Access Novel Modification of Potassium Chloride Induced Cardiac Arrest Model for Aged Mice.(Aging and disease, 2018-02) Liu, Huaqin; Yu, Zhui; Li, Ying; Xu, Bin; Yan, Baihui; Paschen, Wulf; Warner, David S; Yang, Wei; Sheng, HuaxinExperimental cardiac arrest (CA) in aging research is infrequently studied in part due to the limitation of animal models. We aimed to develop an easily performed mouse CA model to meet this need. A standard mouse KCl-induced CA model using chest compressions and intravenous epinephrine for resuscitation was modified by blood withdrawal prior to CA onset, so as to decrease the requisite KCl dose to induce CA by decreasing the circulating blood volume. The modification was then compared to the standard model in young adult mice subjected to 8 min CA. 22-month old mice were then subjected to 8 min CA, resuscitated, and compared to young adult mice. Post-CA functional recovery was evaluated by measuring spontaneous locomotor activity pre-injury, and on post-CA days 1, 2, and 3. Neurological score and brain histology were examined on day 3. Brain elF2α phosphorylation levels were measured at 1 h to verify tissue stress. Compared to the standard model, the modification decreased cardiopulmonary resuscitation duration and increased 3-day survival in young mice. For aged mice, survival was 100 % at 24 h and 54% at 72 h. Neurological deficit was present 3 days post-CA, although more severe versus young mice. Mild neuronal necrosis was present in the cortex and hippocampus. The modified model markedly induced elF2α phosphorylation in both age groups. This modified procedure makes the CA model feasible in aged mice and provides a practical platform for understanding injury mechanisms and developing therapeutics for elderly patients.Item Open Access Uncoupling skeletal and connective tissue patterning: conditional deletion in cartilage progenitors reveals cell-autonomous requirements for Lmx1b in dorsal-ventral limb patterning(2010) Li, Ying; Qiu, Qiong; Watson, Spenser S; Schweitzer, Ronen; Johnson, Randy LIntegration of muscle, connective tissue and skeletal patterning during development is essential for proper functioning of the musculoskeletal system. How this integration is achieved is poorly understood. There is ample evidence suggesting that skeletal pattern is programmed autonomously, whereas muscle pattern is, for the most part, programmed non-cell-autonomously. Connective tissues depend upon both muscle and skeletal tissues for their proper survival and development. Here, we employed a novel approach to dissect the coordination of musculoskeletal patterning during mouse limb development. Using both conditional gain- and loss-of-function approaches, we selectively deleted or activated the LIM-homeodomain transcription factor Lmx1b in skeletal progenitors using a Sox9-Cre knock-in allele. As Lmx1b is both necessary and sufficient to specify dorsal pattern, this approach allowed us to investigate the effect of selectively deleting or activating Lmx1b in skeletal progenitors on muscle, connective and skeletal tissues during limb development. Our results indicate that whereas Lmx1b activity is required autonomously in skeletal progenitors to direct dorsal pattern, loss or gain of Lmx1b activity in skeletal progenitors has no effect on muscle or connective tissue patterning. Hence, we show for the first time that skeletal and connective tissue patterning can be uncoupled, indicating a degree of autonomy in the formation of the musculoskeletal system.Item Open Access XBP1 (X-Box-Binding Protein-1)-Dependent O-GlcNAcylation Is Neuroprotective in Ischemic Stroke in Young Mice and Its Impairment in Aged Mice Is Rescued by Thiamet-G.(Stroke, 2017-06) Jiang, Meng; Yu, Shu; Yu, Zhui; Sheng, Huaxin; Li, Ying; Liu, Shuai; Warner, David S; Paschen, Wulf; Yang, WeiBackground and purpose
Impaired protein homeostasis induced by endoplasmic reticulum dysfunction is a key feature of a variety of age-related brain diseases including stroke. To restore endoplasmic reticulum function impaired by stress, the unfolded protein response is activated. A key unfolded protein response prosurvival pathway is controlled by the endoplasmic reticulum stress sensor (inositol-requiring enzyme-1), XBP1 (downstream X-box-binding protein-1), and O-GlcNAc (O-linked β-N-acetylglucosamine) modification of proteins (O-GlcNAcylation). Stroke impairs endoplasmic reticulum function, which activates unfolded protein response. The rationale of this study was to explore the potentials of the IRE1/XBP1/O-GlcNAc axis as a target for neuroprotection in ischemic stroke.Methods
Mice with Xbp1 loss and gain of function in neurons were generated. Stroke was induced by transient or permanent occlusion of the middle cerebral artery in young and aged mice. Thiamet-G was used to increase O-GlcNAcylation.Results
Deletion of Xbp1 worsened outcome after transient and permanent middle cerebral artery occlusion. After stroke, O-GlcNAcylation was activated in neurons of the stroke penumbra in young mice, which was largely Xbp1 dependent. This activation of O-GlcNAcylation was impaired in aged mice. Pharmacological increase of O-GlcNAcylation before or after stroke improved outcome in both young and aged mice.Conclusions
Our study indicates a critical role for the IRE1/XBP1 unfolded protein response branch in stroke outcome. O-GlcNAcylation is a prosurvival pathway that is activated in the stroke penumbra in young mice but impaired in aged mice. Boosting prosurvival pathways to counterbalance the age-related decline in the brain's self-healing capacity could be a promising strategy to improve ischemic stroke outcome in aged brains.