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Open Access Publications from the University of California

Scholarly Works (7 results)

  • Multimedia
  • Peer Reviewed
CMPM 80K (2020)
You wake up alone in an empty house with a relic which your parent gave you. You need to choose whether the relic is part of a sword or a lucky coin that will lead to different stories and endings. You need to make various decisions and try to stop the conflicts between two powers called Clan and Kingdom.
  • 1 supplemental file
  • Article
UCLA Women's Law Journal, Volume 27, Issue 2 (2020)
Lawsuits about groom-to-bride marriage payments are arriving in Chinese courts, challenging traditional ideas about marriage formation.  Through the lens of case files, I examine the dissolution of marriages (or quasimarital relationships) formed by marriage payment agreements and analyze the anticommodification views expressed by feminists and legal scholars.  In these cases, judges wrestle with two competing considerations: their own antimarriage payment and pro-groom views on one hand and the litigants’ economic conception of marriage on the other.  The former urges judges to rule for the grooms, and the latter for the brides.  In balancing these two considerations, judges generally order a partial or full repayment of the payment when the relationship dissolves.  I also examine feminist concerns of voluntariness and fairness in the commodification of sexuality.  The current theoretical and judicial frameworks do not account for the divergent power dynamics in individual cases; as a result, the case rulings do not respond appropriately to brides and grooms with differing degrees of agency.  These blind spots may have unintended consequences, including inflating prices and reinforcing gender-based asymmetries.  In this Article, I argue that judges should rely on economic analysis rather than moral judgment to better account for the actual dynamics of marriage payment arrangements.  Framing my analysis is a transactional conception of marriage and an economic approach to family, both of which have the potential to further our understanding of marriage and to advance gender equality.
    Cover page: Marriage and Money Entangled: Commodification, Agency, and Economic Analysis in Chinese Marriage Payment Lawsuits
    • Thesis
    • Peer Reviewed
    UC San Diego Electronic Theses and Dissertations (2022)

    In this dissertation, we utilize the novel statistical methods for obtaining causal effect under competing risks and semi-competing risks data in survival analysis. This dissertation is comprised of three main settings. In the first setting, we aim to assess the causal effect of mid-life alcohol exposure to the late life cognitive score which is related to Alzheimer’s disease (AD) using a large scale longitudinal data. We applied the marginal structural model (MSM) with inverse probability weighted (IPW) to adjust for time-varying confounding. We found that there is a significant decline in cognitive scores among heavy drinkers compared always light drinker. However, since the cognitive scores also changes over time, learning the relationship of alcohol exposure and time to cognitive impairment is also worth to explore.

    In the second setting, we are interested in mid-life alcohol exposure to late life time to cognitive impairment which is also related to AD. Under this setting, as people are in their late-life stage, death prevents us from observing cognitive impairment. In survival analysis, death is considering as competing event. To estimate the causal effect of point treatment to time to event with the existence of competing event, we applied the MSM Cox proportional hazards model with IPW. Since hazard ratio is hard to interpret in medical research, we proposed predicted risk contrasts formula under the MSM Cox model.

    Observing the trend that people die quickly after experiencing cognitive impairment, in the third settings, we proposed a MSM illness-death to assess the causal effect for alcohol exposure to time to cognitive impairment, death and death after cognitive impairment. We considered two specific such models, the usual Markov illness-death structural model and the general Markov illness-death structural model which incorporates a frailty term. For interpretation purposes, risk contrasts under the structural models are defined. To accommodate the possibility of misspecification of propensity score model, we also derived the augmented IPW estimator under MSM illness-death usual Markov model.

      Cover page: Causal Inference for Competing Risks and Semi-competing Risks Data
      • Article
      • Peer Reviewed
      UC Berkeley Previously Published Works (2016)
      Congestion plays a central role in urban and transportation economics. Existing estimates of congestion costs rely on stated or revealed preferences studies. We explore a complementary measure of congestion costs based on self-reported happiness. Exploiting quasi-random variation in daily congestion in Beijing that arises because of superstitions about the number four, we estimate a strong effect of daily congestion on self-reported happiness. When benchmarking this effect against the relationship between income and self-reported happiness we compute implied congestion costs that are several times larger than conventional estimates. Several factors, including the value of reliability and externalities on non-travelers, can reconcile our alternative estimates with the existing literature.
        • Article
        • Peer Reviewed
        UC Berkeley Previously Published Works (2020)
        Polaritons in two-dimensional (2D) materials have shown their unique capabilities to concentrate light into deep subwavelength scales. Precise control of the excitation and propagation of 2D polaritons has remained a central challenge for future on-chip nanophotonic devices and circuits. To solve this issue, we exploit Cherenkov radiation, a classic physical phenomenon that occurs when a charged particle moves at a velocity greater than the phase velocity of light in that medium, in low-dimensional material heterostructures. Here, we report an experimental observation of Cherenkov phonon polariton wakes emitted by superluminal one-dimensional plasmon polaritons in a silver nanowire and hexagonal boron nitride heterostructure using near-field infrared nanoscopy. The observed Cherenkov radiation direction and radiation rate exhibit large tunability through varying the excitation frequency. Such tunable Cherenkov phonon polaritons provide opportunities for novel deep subwavelength-scale manipulation of light and nanoscale control of energy flow in low-dimensional material heterostructures.
          Cover page: Tunable Cherenkov Radiation of Phonon Polaritons in Silver Nanowire/Hexagonal Boron Nitride Heterostructures
          • Article
          • Peer Reviewed
          UC Berkeley Previously Published Works (2019)
          Strain plays an important role in condensed matter physics and materials science because it can strongly modify the mechanical, electrical, and optical properties of a material and even induce a structural phase transition. Strain effects are especially interesting in atomically thin two-dimensional (2D) materials, where unusually large strain can be achieved without breaking them. Measuring the strain distribution in 2D materials at the nanometer scale is therefore greatly important but is extremely challenging experimentally. Here, we use near-field infrared nanoscopy to demonstrate phonon polariton-assisted mapping and quantitative analysis of strain in atomically thin polar crystals of hexagonal boron nitride (hBN) at the nanoscale. A local strain as low as 0.01% can be detected using this method with ∼20 nm spatial resolution. Such ultrasensitive nanoscale strain imaging and analysis technique opens up opportunities for exploring unique local strain structures and strain-related physics in 2D materials. In addition, experimental evidence for local strain-induced phonon polariton reflection is also provided, which offers a new approach to manipulate light at deep subwavelength scales for nanophotonic devices.
            Cover page: Phonon Polariton-assisted Infrared Nanoimaging of Local Strain in Hexagonal Boron Nitride
            • Article
            • Peer Reviewed
            UC San Diego Previously Published Works (2022)

            Background & aims

            We aimed to compare safety and effectiveness of vedolizumab to tumor necrosis factor (TNF)-antagonist therapy in ulcerative colitis in routine practice.

            Methods

            A multicenter, retrospective, observational cohort study (May 2014 to December 2017) of ulcerative colitis patients treated with vedolizumab or TNF-antagonist therapy. Propensity score weighted comparisons for development of serious adverse events and achievement of clinical remission, steroid-free clinical remission, and steroid-free deep remission. A priori determined subgroup comparisons in TNF-antagonist-naïve and -exposed patients, and for vedolizumab against infliximab and subcutaneous TNF-antagonists separately.

            Results

            A total of 722 (454 vedolizumab, 268 TNF antagonist) patients were included. Vedolizumab-treated patients were more likely to achieve clinical remission (hazard ratio [HR], 1.651; 95% confidence interval [CI], 1.229-2.217), steroid-free clinical remission (HR, 1.828; 95% CI, 1.135-2.944), and steroid-free deep remission (HR, 2.819; 95% CI, 1.496-5.310) than those treated with TNF antagonists. Results were consistent across subgroup analyses in TNF-antagonist-naïve and -exposed patients, and for vedolizumab vs infliximab and vs subcutaneous TNF-antagonist agents separately. Overall, there were no statistically significant differences in the risk of serious adverse events (HR, 0.899; 95% CI, 0.502-1.612) or serious infections (HR, 1.235; 95% CI, 0.608-2.511) between vedolizumab-treated and TNF-antagonist-treated patients. However, in TNF-antagonist-naïve patients, vedolizumab was less likely to be associated with serious adverse events than TNF antagonists (HR, 0.192; 95% CI, 0.049-0.754).

            Conclusions

            Treatment of ulcerative colitis with vedolizumab is associated with higher rates of remission than treatment with TNF-antagonist therapy in routine practice, and lower rates of serious adverse events in TNF-antagonist-naïve patients.
              Cover page: Comparative Safety and Effectiveness of Vedolizumab to Tumor Necrosis Factor Antagonist Therapy for Ulcerative Colitis
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