Essays on Dispersion, Fairness Perception and Partitioning of Online Prices

My dissertation is primarily on online pricing, by empirically investigating how formats and structures of prices influence consumer responses and subsequent purchasing behavior, brand choice, etc. Currently, three essays of my dissertation explore topics on price fairness perception, price dispersion, as well as price partitioning. First, although previous researchers have tested effects of price changes on consumer\u27s perceptions on price (e.g., Maxwell 1999, Campbell 2007), little work has focused on the effects of prices/costs levels on online price judgments and virtually none has examined it jointly with both internal/external reference prices from multiple comparison parties. Less work has applied price decreasing and increasing together to observe (un)fairness or associated them with asymmetric liking and disliking judgments (Herr and Page 2004). To fill this gap, we employ an expected utility model incorporating emotional factors such as disappointment (elation) and regret (rejoicing) to model online price fairness perceptions. We demonstrate a two-stage evaluation and find interesting asymmetric patterns of significant effects of four emotions on price fairness. Second, there does not exist yet a quantitative review synthesizing and explaining the discrepancy of findings on price dispersion. An empirical generalization is conducted to statistically and quantitatively summarize in which way online price dispersion goes, and what are the true determinants of the magnitude of price dispersion in E-commerce. By a meta-analysis study, we find that product category, measurement of price dispersion, controlling for heterogeneity in the study and so on, are significant factors. Third, shipping and handling (S&H) fee is examined as a popular form of partitioned price offered by E-tailers. We employ a Gain-and-Loss Utility model incorporating different levels of price gains and losses presented to customers in the transactions to model online purchase behaviors in a strategic pricing framework. We find significant asymmetry in the effects of price surcharges and price discounts on purchase quantity as well as on how customers organize and manage their shopping baskets

On Generalization and Computation of Tukey's Depth: Part I

Tukey's depth offers a powerful tool for nonparametric inference and estimation, but also encounters serious computational and methodological difficulties in modern statistical data analysis. This paper studies how to generalize and compute Tukey-type depths in multi-dimensions. A general framework of influence-driven polished subspace depth, which emphasizes the importance of the underlying influence space and discrepancy measure, is introduced. The new matrix formulation enables us to utilize state-of-the-art optimization techniques to develop scalable algorithms with implementation ease and guaranteed fast convergence. In particular, half-space depth as well as regression depth can now be computed much faster than previously possible, with the support from extensive experiments. A companion paper is also offered to the reader in the same issue of this journal

Toll-like receptor-mediated innate immunity against herpesviridae infection: a current perspective on viral infection signaling pathways

BACKGROUND: In the past decades, researchers have demonstrated the critical role of Toll-like receptors (TLRs) in the innate immune system. They recognize viral components and trigger immune signal cascades to subsequently promote the activation of the immune system. MAIN BODY: Herpesviridae family members trigger TLRs to elicit cytokines in the process of infection to activate antiviral innate immune responses in host cells. This review aims to clarify the role of TLRs in the innate immunity defense against herpesviridae, and systematically describes the processes of TLR actions and herpesviridae recognition as well as the signal transduction pathways involved. CONCLUSIONS: Future studies of the interactions between TLRs and herpesviridae infections, especially the subsequent signaling pathways, will not only contribute to the planning of effective antiviral therapies but also provide new molecular targets for the development of antiviral drugs

Genome-wide eQTLs and heritability for gene expression traits in unrelated individuals

BACKGROUND: While the possible sources underlying the so-called ‘missing heritability’ evident in current genome-wide association studies (GWAS) of complex traits have been actively pursued in recent years, resolving this mystery remains a challenging task. Studying heritability of genome-wide gene expression traits can shed light on the goal of understanding the relationship between phenotype and genotype. Here we used microarray gene expression measurements of lymphoblastoid cell lines and genome-wide SNP genotype data from 210 HapMap individuals to examine the heritability of gene expression traits. RESULTS: Heritability levels for expression of 10,720 genes were estimated by applying variance component model analyses and 1,043 expression quantitative loci (eQTLs) were detected. Our results indicate that gene expression traits display a bimodal distribution of heritability, one peak close to 0% and the other summit approaching 100%. Such a pattern of the within-population variability of gene expression heritability is common among different HapMap populations of unrelated individuals but different from that obtained in the CEU and YRI trio samples. Higher heritability levels are shown by housekeeping genes and genes associated with cis eQTLs. Both cis and trans eQTLs make comparable cumulative contributions to the heritability. Finally, we modelled gene-gene interactions (epistasis) for genes with multiple eQTLs and revealed that epistasis was not prevailing in all genes but made a substantial contribution in explaining total heritability for some genes analysed. CONCLUSIONS: We utilised a mixed effect model analysis for estimating genetic components from population based samples. On basis of analyses of genome-wide gene expression from four HapMap populations, we demonstrated detailed exploitation of the distribution of genetic heritabilities for expression traits from different populations, and highlighted the importance of studying interaction at the gene expression level as an important source of variation underlying missing heritability. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/1471-2164-15-13) contains supplementary material, which is available to authorized users

Metabolic and senescence characteristics associated with the immune microenvironment in ovarian cancer

Ovarian cancer is a highly malignant gynecological cancer influenced by the immune microenvironment, metabolic reprogramming, and cellular senescence. This review provides a comprehensive overview of these characteristics. Metabolic reprogramming affects immune cell function and tumor growth signals. Cellular senescence in immune and tumor cells impacts anti-tumor responses and therapy resistance. Targeting immune cell metabolism and inducing tumor cell senescence offer potential therapeutic strategies. However, challenges remain in identifying specific targets and biomarkers. Understanding the interplay of these characteristics can lead to innovative therapeutic approaches. Further research is needed to elucidate mechanisms, validate strategies, and improve patient outcomes in ovarian cancer