Essays in Macroeconomics and Financial Economics

This dissertation contains three essays in macroeconomics and financial economics that aim to understand the importance of information and intermediaries on aggregate fluctuations, and consequently, the role of macroeconomic policy. Chapter 1 provides direct evidence of the importance of firm attention to macroeconomic dynamics. This chapter develops a text-based measure of firm attention to macroeconomic news and documents firm attention that is polarized and countercyclical. Differences in attention lead to asymmetric responses to monetary policy: expansionary monetary shocks raise stock returns of attentive firms more than those of inattentive firms, and contractionary shocks lower returns of attentive firms by less. In a quantitative model of rationally inattentive firms with parameters for information frictions calibrated using the text-based measure, firms invest in attention endogenously and face heterogeneous information costs. Less attentive firms adjust prices slowly in response to monetary innovations, which yields non-neutrality. As average attention varies over the business cycle, so does the efficacy of monetary policy. Chapter 2 provides empirical evidence of the causal effects of changes in financial intermediaries' net worth in the aggregate economy. The empirical strategy developed in this chapter identifies financial shocks as the high-frequency changes in the market value of intermediaries' net worth in a narrow window around their earnings announcements, based on tick-by-tick data. News of declines in U.S. intermediaries' net worth leads to significant declines in the market value of nonfinancial firms. These effects are more pronounced for small firms and when the aggregate net worth of financial intermediaries is low. In addition, this chapter discusses channels through which intermediaries affect nonfinancial firms, which provides evidence of the effect of intermediaries on corporate borrowing costs. Chapter 3 provides empirical evidence that economic narratives influence consumer sentiment. It develops a framework that captures news narratives of economic events using natural language processing and traces consumers' exposure to different narratives using retweeting activities. The framework is applied to study the narratives surrounding the yield curve inversion. Exposure to the negative narrative of an imminent recession causes consumers to display a more pessimistic sentiment, while exposure to the positive narrative that recession concerns are overblown leads to no change in consumer sentiment.PHDEconomicsUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/169936/1/wtsong_1.pd

Phosphodiesterase type 5 inhibitors and risk of melanoma: A meta-analysis

Background The association between phosphodiesterase type 5 (PDE5) inhibitors and melanoma risk is controversial. Objective We quantify the association between use of PDE5 inhibitors and melanoma. Methods We systematically searched PubMed, Embase, the Cochrane Central Register of Controlled Trials, Web of Science, and ClinicalTrials.gov for studies that were conducted up to July 13, 2016, and evaluated the association between PDE5 inhibitors and skin cancer. Random effects meta-analyses were used to calculate the adjusted odds ratio (OR) with the 95% confidence interval (CI). Results Five observational studies were included. Compared with PDE5 inhibitor nonuse, PDE5 inhibitor use was slightly but significantly associated with an increased risk for development of melanoma (OR, 1.12; 95% CI, 1.03-1.21) and basal cell carcinoma (OR, 1.14; 95% CI, 1.09-1.19) but not squamous cell carcinoma. For melanoma risk, none of the prespecified factors (dose of PDE5 inhibitor, study design, and study region) significantly affected the results (P > .05). Our sensitivity analysis confirmed the stability of the results. Limitations We included only observational studies, which had some heterogeneities and inconsistent controlling for potential confounders. Conclusions Use of PDE5 inhibitors may be associated with a slightly increased risk for development of melanoma and basal cell carcinoma but not squamous cell carcinoma. However, further large well-conducted prospective studies with adequate adjustment for potential confounders are required for confirmation

Sentiment Word Aware Multimodal Refinement for Multimodal Sentiment Analysis with ASR Errors

Multimodal sentiment analysis has attracted increasing attention and lots of models have been proposed. However, the performance of the state-of-the-art models decreases sharply when they are deployed in the real world. We find that the main reason is that real-world applications can only access the text outputs by the automatic speech recognition (ASR) models, which may be with errors because of the limitation of model capacity. Through further analysis of the ASR outputs, we find that in some cases the sentiment words, the key sentiment elements in the textual modality, are recognized as other words, which makes the sentiment of the text change and hurts the performance of multimodal sentiment models directly. To address this problem, we propose the sentiment word aware multimodal refinement model (SWRM), which can dynamically refine the erroneous sentiment words by leveraging multimodal sentiment clues. Specifically, we first use the sentiment word position detection module to obtain the most possible position of the sentiment word in the text and then utilize the multimodal sentiment word refinement module to dynamically refine the sentiment word embeddings. The refined embeddings are taken as the textual inputs of the multimodal feature fusion module to predict the sentiment labels. We conduct extensive experiments on the real-world datasets including MOSI-Speechbrain, MOSI-IBM, and MOSI-iFlytek and the results demonstrate the effectiveness of our model, which surpasses the current state-of-the-art models on three datasets. Furthermore, our approach can be adapted for other multimodal feature fusion models easily. Data and code are available at https://github.com/albertwy/SWRM.Comment: Findings of ACL 202

Associations between smoking behavior-related alleles and the risk of melanoma

Several studies have reported that cigarette smoking is inversely associated with the risk of melanoma. This study further tested whether incorporating genetic factors will provide another level of evaluation of mechanisms underlying the association between smoking and risk of melanoma. We investigated the association between SNPs selected from genome-wide association studies (GWAS) on smoking behaviors and risk of melanoma using 2,298 melanoma cases and 6,654 controls. Among 16 SNPs, three (rs16969968 [A], rs1051730 [A] and rs2036534 [C] in the 15q25.1 region) reached significance for association with melanoma risk in men (0.01 < = P values < = 0.02; 0.85 < = Odds Ratios (ORs) <= 1.20). There was association between the genetic scores based on the number of smoking behavior-risk alleles and melanoma risk with P-trend = 0.005 among HPFS. Further association with smoking behaviors indicating those three SNPs (rs16969968 [A], rs1051730 [A] and rs2036534 [C]) significantly associated with number of cigarettes smoked per day, CPD, with P = 0.009, 0.011 and 0.001 respectively. The SNPs rs215605 in the PDE1C gene and rs6265 in the BDNF gene significantly interacted with smoking status on melanoma risk (interaction P = 0.005 and P = 0.003 respectively). Our study suggests that smoking behavior-related SNPs are likely to play a role in melanoma development and the potential public health importance of polymorphisms in the CHRNA5-A3-B4 gene cluster. Further larger studies are warranted to validate the findings

A Hybrid Social Network-based Collaborative Filtering Method for Personalized Manufacturing Service Recommendation

Nowadays, social network-based collaborative filtering (CF) methods are widely applied to recommend suitable products to consumers by combining trust relationships and similarities in the preference ratings among past users. However, these types of methods are rarely used for recommending manufacturing services. Hence, this study has developed a hybrid social network-based CF method for recommending personalized manufacturing services. The trustworthy enterprises and three types of similar enterprises with different features were considered as the four influential components for calculating predicted ratings of candidate services. The stochastic approach for link structure analysis (SALSA) was adopted to select top K trustworthy enterprises while also considering their reputation propagation on enterprise social network. The predicted ratings of candidate services were computed by using an extended user-based CF method where the particle swarm optimization (PSO) algorithm was leveraged to optimize the weights of the four components, thus making service recommendation more objective. Finally, an evaluation experiment illustrated that the proposed method is more accurate than the traditional user-based CF method

Refined Qingkailing Protects MCAO Mice from Endoplasmic Reticulum Stress-Induced Apoptosis with a Broad Time Window

In the current study, we are investigating effect of refined QKL on ischemia-reperfusion-induced brain injury in mice. Methods. Mice were employed to induce ischemia-reperfusion injury of brain by middle cerebral artery occlusion (MCAO). RQKL solution was administered with different doses (0, 1.5, 3, and 6 mL/kg body weight) at the same time of onset of ischemia, and with the dose of 1.5 mL/kg at different time points (0, 1.5, 3, 6, and 9 h after MCAO). Neurological function and brain infarction were examined and cell apoptosis and ROS at prefrontal cortex were evaluated 24 h after MCAO, and western blot and intracellular calcium were also researched, respectively. Results. RQKL of all doses can improve neurological function and decrease brain infarction, and it performed significant effect in 0, 1.5, 3, and 6 h groups. Moreover, RQKL was able to reduce apoptotic process by reduction of caspase-3 expression, or restraint of eIF2a phosphorylation and caspase-12 activation. It was also able to reduce ROS and modulate intracellular calcium in the brain. Conclusion. RQKL can prevent ischemic-induced brain injury with a time window of 6 h, and its mechanism might be related to suppress ER stress-mediated apoptotic signaling

Topical Halometasone Reduces Acute Adverse Effects Induced by Pulsed Dye Laser for Treatment of Port Wine Stain Birthmarks

Introduction: Pulsed dye laser (PDL) for treatment of port wine stain (PWS) usually causes some acute adverse effects, including pain, erythema, scabbing and swelling. This study aimed to determine whether topical halometasone can be used to reduce these acute adverse effects for post-PDL care of patients.Methods: A total of 40 PWS subjects were enrolled in this study and randomly assigned into two regimens: PDL alone and PDL + halometasone. All subjects were given a single treatment of PDL with wavelength of 595 nm, fluence of 8.0~13.5 J/cm2, pulse duration of 0.45~20 ms (We mainly used purpuric pulse duration for PWS) and spot size of 7 mm. Subjects in the PDL + halometasone group received topical application of halometasone daily for 3 days. Subjects were followed-up on days 3, 7 and one month post-PDL to evaluate the reduction of adverse effects.Results: Subjects in the PDL + halometasone group had significantly improved erythema and scab scores and had less erythema duration days as compared to those in the PDL alone group. Topical halometasone also showed a decrease in pain index among subjects, but was statistically insignificant. Topical halometasone did not affect the ultimate efficacy of PDL treatment for PWS.Conclusion: Topical halometasone can significantly reduce acute adverse effects induced by PDL for treatment of PWS birthmarks, thus providing a safe and efficacious solution for post-PDL care of PWS patients

SIRT2 regulates macrophage chemotaxis by de-modifying histone H4K8 lactylation

Objective·To explore the regulatory role of silent information regulator 2 (SIRT2) in modulating the immune phenotype of macrophages after infection by removing the lactylation at H4K8 site of histone and the corresponding mechanism.Methods·Human THP-1 leukemia cells were induced by phorbol 12-myristate 13-acetate (PMA) and stimulated by lipopolysaccharide (LPS) to establish a macrophage infection model. Macrophages without LPS treatment (pTHP-1) were set as the control (CTRL) group, and macrophages with LPS treatment were set as the infected (LPS) group. Western blotting was used to detect the level of histone modification and SIRT2 protein in macrophages. RT-qPCR was used to detect the expression level of glycolytic key enzymes [phosphofructokinase liver type (PFKL), lactate dehydrogenase A (LDHA)] and modulators genes hypoxia inducible factor 1α (HIF-1α), and the expression level of Sirtuin genes and HDAC genes between the two groups. Transwell was used to detect the ability of macrophage chemotaxis. Lentivirus packaging and cell infection were used to construct SIRT2 overexpression cell line. The interaction analysis method of RNA sequencing (RNA-seq) and chromatin immunoprecipitation sequencing (ChIP-seq) was used to analyze the difference and pathway enrichment of the genes specifically bound to H4K8 lactylation (H4K8la).Results·Compared to the CTRL group, macrophage glycolysis was upregulated and the level of H4K8la was significantly increased in the LPS group (P0.05). The interactive analysis of ChIP-seq and RNA-seq revealed that chemotaxis-related genes were regulated by H4K8la, and macrophage chemotaxis ability significantly decreased after the overexpression of SIRT2 and downregulation of H4K8la (P<0.05).Conclusion·SIRT2 can change the expression of target genes related to chemotaxis by removing H4K8la modification, thereby reducing the chemotaxis ability of macrophages. Targeting SIRT2 and H4K8la modification may help control inflammation mediated by macrophages