1,380 research outputs found

    Trickle-Down Technology and Screening of a Durable Goods Monopolist

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    We show that when it takes time for a durable goods monopolist to make its high-end new technology accessible to low-end market (the trickle-down technology constraint), the monopolist's high-end product might have a higher-than-optimum quality. This result differs from conventional screening models, in which the qualities of non-durable goods supplied by a monopolist never exceed the optimum, and only consumers with the highest valuation consume the efficient quality. In another literature discussing a durable goods monopolist who delays the introduction of low-end product as a marketing strategy, but not due to the trickle-down constraint, the qualities will not exceed the optimum either. Our results show that the trickle-down constraint will make the monopolist chooses a higher-than-optimum quality when the difference of the valuations of high demand and low demand consumers are in certain ranges. The intuition follows Spence (1975): the efficient quality is determined by the marginal cost and the average of all consumers' marginal valuations, while the monopolist chooses quality such that the marginal cost equals the marginal consumer's marginal valuation

    Effects of ambiguity in market reaction to changes in stock recommendations

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    This study uses analyst recommendations and three ambiguity proxies, namely ambiguity in fundamentals, ambiguity in information and market ambiguity, to examine market reaction to recommendation changes in the Taiwanese stock market. The authors find that analysts’ recommendation changes have positive effects on subsequent buy-and-hold abnormal returns when market ambiguity is moderate. When ambiguity in fundamentals is low, recommendation changes have a positive influence on smaller firms. The effect of ambiguity in information on stock returns is associated with market ambiguity; market ambiguity is negatively associated with abnormal returns for firms with moderate ambiguity in fundamentals. Investors in a small firm rely more on analyst recommendations

    SeaEval for Multilingual Foundation Models: From Cross-Lingual Alignment to Cultural Reasoning

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    We present SeaEval, a benchmark for multilingual foundation models. In addition to characterizing how these models understand and reason with natural language, we also investigate how well they comprehend cultural practices, nuances, and values. Alongside standard accuracy metrics, we investigate the brittleness of foundation models in the dimensions of semantics and multilinguality. Our analyses span both open-sourced and closed models, leading to empirical results across classic NLP tasks, reasoning, and cultural comprehension. Key findings indicate (1) Most models exhibit varied behavior when given paraphrased instructions. (2) Many models still suffer from exposure bias (e.g., positional bias, majority label bias). (3) For questions rooted in factual, scientific, and commonsense knowledge, consistent responses are expected across multilingual queries that are semantically equivalent. Yet, most models surprisingly demonstrate inconsistent performance on these queries. (4) Multilingually-trained models have not attained "balanced multilingual" capabilities. Our endeavors underscore the need for more generalizable semantic representations and enhanced multilingual contextualization. SeaEval can serve as a launchpad for more thorough investigations and evaluations for multilingual and multicultural scenarios.Comment: 15 pages, 7 figure

    Ankle-Brachial Index Is a Powerful Predictor of Renal Outcome and Cardiovascular Events in Patients with Chronic Kidney Disease

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    Ankle-brachial index (ABI) is an accurate tool to diagnose peripheral arterial disease. The aim of this study was to evaluate whether ABI is also a good predictor of renal outcome and cardiovascular events in patients with chronic kidney disease (CKD). We enrolled 436 patients with stage 3–5 CKD who had not been undergoing dialysis. Patients were stratified into two groups according to the ABI value with a cut point of 0.9. The composite renal outcome, including doubling of serum creatinine level and commencement of dialysis, and the incidence of cardiovascular events were compared between the two groups. After a median follow-up period of 13 months, the lower ABI group had a poorer composite renal outcome (OR = 2.719, P = 0.015) and a higher incidence of cardiovascular events (OR = 3.260, P = 0.001). Our findings illustrated that ABI is a powerful predictor of cardiovascular events and renal outcome in patients with CKD

    Factor analyses of a social support scale using two methods

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    Purpose: Evaluation and comparison of the factor structure of the Medical Outcomes Study Social Support Survey (MOS-SSS) using both confirmatory factor analysis (CFA) and exploratory factor analysis (EFA) with two samples of people living with HIV/AIDS in China. Methods: Secondary analyses were conducted with data from two comparable samples of 320 people living with HIV/AIDS from the same hospital using the same inclusion criteria. The first sample of 120 was collected in 2006, and the second sample of 200 was collected in 2012. For each sample, CFA was first performed on the original four-factor structure to check model fit, followed by EFA to explore other factor structures and a subsequent CFA for model fit statistics to be compared to the original four-factor CFA. Results: In both samples, CFA on the originally hypothesized four-factor structure yielded an acceptable model fit. The EFA yielded a two-factor solution in both samples, with different items included in each factor for the two samples. Comparison of CFA on the a priori four-factor structure and the new two-factor structure in both samples indicated that both factor structures were of acceptable model fit, with the four-factor model performing slightly better than the two-factor model. Conclusion: Factor structure of the MOS-SSS is method-dependent, with CFA supporting a four-factor structure, while EFA yielded a two-factor structure in two separate samples. We need to be careful in selecting the analytic method when applying the MOS-SSS to various samples and choose the factor structure that best fits the theoretical model

    Antiretroviral Therapy (ART) Side Effect Impacted on Quality of Life, and Depressive Symptomatology: A Mixed-Method Study

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    Antiretroviral therapy (ART) is known for its side effects. In this paper, we describe ART side effects as experienced by Chinese HIV+ individuals. This study presents two stages of a research project, combining qualitative in-depth interviews (29 HIV+ participants) with quantitative statistical data analysis (N = 120). All data was collected between July 2005 to March 2008 at Beijing\u27s Ditan Hospital. Consent was obtained from each participant for the qualitative interview and again for the quantitative survey. During in-depth interviews, Chinese HIV+ patients reported experiencing digestive discomfort, skin rashes, numbness, memory loss, nightmares, and dizziness, which not only brought them physical discomfort, but also interrupted different dimensions of their social lives. Furthermore, multiple regression analyses revealed that those who reported more severe side effects also experienced greater depressive mood after controlling for other clinical and psychosocial factors. ART side effects are one of the primary reasons causing HIV+ individuals to delay or stop taking life-saving medication; therefore, clinical interventions are critically needed to assist HIV+ individuals in managing ART side effects. ART side effects reinforced existing negative attitudes toward ART and lead to lower ART adherence. Future research should focus on developing culturally sensitive interventions to enhance HIV+ selfmanagement, to alleviate physical and psychological burden from ART and HIV

    Preoperative treatment with 5α-reductase inhibitors and the risk of hemorrhagic events in patients undergoing transurethral resection of the prostate – A population-based cohort study

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    OBJECTIVES: To assess the associations between preoperative treatment with 5-alpha reductase inhibitors and the risks of blood transfusion during transurethral resection of the prostate and blood clot evacuation or emergency department visits for hematuria within 1 month after surgery. METHODS: We used data from the Taiwan National Health Insurance Research Database in this population-based cohort study. A total of 3,126 patients who underwent first-time transurethral resection of the prostate from 2004 to 2013 were identified. Adjusted odds ratios estimated by multiple logistic regression models were used to assess the independent effects of the preoperative use of 5-alpha reductase inhibitors on the risks of perioperative hemorrhagic events after adjustment for potential confounders. RESULTS: Two hundred and ninety-seven (9.4%) patients were treated with 5-alpha reductase inhibitors fo

    Fatigue and sleep disturbance related to perceived stress in Chinese HIV-positive individuals: A mixed methods study

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    Background Few studies of HIV+ individuals in China have examined the associations between HIV-related stress with sleep disturbance and fatigue, which are common complaints among people living with HIV/AIDS (PLWHA). We carried out this study to examine the relationships among perceived stress, sleep disturbance, and fatigue in PLWHA in China. Methods A mixed methods study design was used during data collection in Shanghai, China, from December 2009 to March 2010. Qualitative in-depth interviews were conducted with 19 HIV+ females. Additionally, cross-sectional audio computer-assisted self-interviews (ACASI) were conducted to collect quantitative data from a convenience sample of 107 HIV+ patients (84% were male) including the following scales: 1) Perceived Stress Scale for PLWHA, 2) General Sleep Disturbance Scale, and 3) Fatigue Scale. Results The major themes that emerged from the in-depth interviews were around life stress with HIV, sleep disturbance, and fatigue. Participants presented varying amounts of stress around worrying about whether to disclose their diagnosis and whether they might transmit the disease to their family. In addition, in the cross-sectional data, 40% of the participants reported clinically significant sleep disturbances (GSDS \u3e 3) with an average of 3 nights of disturbed sleep in the past week (M=2.87, SD=1.21) and moderate fatigue severity (M=5.24, SD=2.27). In mediation analyses, the data suggests that the relationship between perceived stress and fatigue was largely (53%) mediated through sleep disturbance. Conclusions Chinese PLWHA described how stress had caused them to become sleepless and fatigued. The quantitative data also demonstrated significant levels of sleep disturbance and fatigue, where were due to perceived stress with HIV disease. A systematic self-management intervention to decrease perceived stress should be designed and implemented in mental health resource-limited settings such as China in order to reduce sleep disturbance and fatigue

    Integrative analysis of disulfidptosis and immune microenvironment in hepatocellular carcinoma: a putative model and immunotherapeutic strategies

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    BackgroundHepatocellular carcinoma (HCC) is a malignant tumor with a high rate of recurrence and m metastasis that does not respond well to current therapies and has a very poor prognosis. Disulfidptosis is a novel mode of cell death that has been analyzed as a novel therapeutic target for HCC cells.MethodsThis study integrated bulk ribonucleic acid (RNA) sequencing datasets, spatial transcriptomics (ST), and single-cell RNA sequencing to explore the landscape of disulfidptosis and the immune microenvironment of HCC cells.ResultsWe developed a novel model to predict the prognosis of patients with HCC based on disulfidptosis. The model has good stability, applicability, and prognostic and immune response prediction abilities. N-myc downregulated gene1 (NDRG1) may contribute to poor prognosis by affecting macrophage differentiation, thus allowing HCC cells to evade the immune system.ConclusionOur study explores the disulfidptosis of HCC cells through multi-omics and establishes a new putative model that explores possible targets for HCC treatment
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