433 research outputs found

    Not feeling the buzz: Correction study of mispricing and inefficiency in online sportsbooks

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    We present a strict replication and correction of results published in a recent article (Ramirez, P., Reade, J.J., Singleton, C., Betting on a buzz: Mispricing and inefficiency in online sportsbooks, International Journal of Forecasting, 2022, doi:10.1016/j.ijforecast.2022.07.011). RRS introduced a novel "buzz factor" metric for tennis players, calculated as the log difference between the number of Wikipedia profile page views a player receives the day before a tennis match and the player's median number of daily profile views. The authors claim that their buzz factor metric is able to predict mispricing by bookmakers and they demonstrate that it can be used to form a profitable strategy for betting on tennis match outcomes. Here, we use the same dataset as RRS to reproduce their results exactly. However, we discover that the published results are significantly affected by a single bet (the "Hercog" bet) that returns substantial outlier profits; and these profits are generated by taking advantage of erroneously long odds in the out-of-sample test data. Once this data quality issue is addressed, we show that the strategy of RRS is no longer profitable in "practical" scenarios. Using an extended and cleaned dataset, we then perform further exploration of the models and show that the "impractical" betting strategy that uses best odds in the market remains profitable (in theory). However, evidence suggests that the vast majority of returns are generated by exploiting individual bookmaker's mispricing of odds relative to the market, and the novel buzz factor metric has negligible contribution to profits. We make all code and data available online.Comment: 26 pages, 2 figures. This paper is a replication study. Problems in the original study are discovered and corrected. Replication code and data are available online: https://github.com/Faxulous/notFeelingTheBuz

    Not feeling the buzz:Correction study of mispricing and inefficiency in online sportsbooks

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    We present a strict replication and correction of results published in a recent article (Ramirez, P., Reade, J.J., Singleton, C., Betting on a buzz: Mispricing and inefficiency in online sportsbooks, International Journal of Forecasting, 2022, doi:10.1016/j.ijforecast.2022.07.011). RRS introduced a novel "buzz factor" metric for tennis players, calculated as the log difference between the number of Wikipedia profile page views a player receives the day before a tennis match and the player's median number of daily profile views. The authors claim that their buzz factor metric is able to predict mispricing by bookmakers and they demonstrate that it can be used to form a profitable strategy for betting on tennis match outcomes. Here, we use the same dataset as RRS to reproduce their results exactly. However, we discover that the published results are significantly affected by a single bet (the "Hercog" bet) that returns substantial outlier profits; and these profits are generated by taking advantage of erroneously long odds in the out-of-sample test data. Once this data quality issue is addressed, we show that the strategy of RRS is no longer profitable in "practical" scenarios. Using an extended and cleaned dataset, we then perform further exploration of the models and show that the "impractical" betting strategy that uses best odds in the market remains profitable (in theory). However, evidence suggests that the vast majority of returns are generated by exploiting individual bookmaker's mispricing of odds relative to the market, and the novel buzz factor metric has negligible contribution to profits. We make all code and data available online

    Institutional maintenance work and power preservation in business exchanges: Insights from industrial supplier workshops

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    This paper aims to offer new theoretical and empirical insights into power dynamics in an industrial supplier workshop setting. Theoretically, it advances an institutional perspective on supplier workshops as an important venue in managing, preserving and instituting industrial market power. Based on a detailed ethnographic analysis of an industrial workshop setting, this article investigates the institutional maintenance work of Retail Co. in preserving the power dynamics of market dominance in business exchanges and market structures. Our findings revealed three previously unreported insights into the subtle, but nonetheless pervasive power from institutional maintenance work in an industrial workshop setting. First, the institutional workshop work comprised a cultural performance; constituting socialization practice through a performance game, the power of numbers in field comprehension and an award ceremony. Second, the institutional workshop work mobilized projective agency, stipulating, directing and appealing for the instituting of distinct market rules and collective identities. Finally, the institutional workshop work increases supplier docility and utility via the regulative technologies-of-the-self to enhance business planning, operations and market decision-making practice, without necessarily being seen to be disciplinarian. (C) 2015 Elsevier Inc. All rights reserved

    Salmonella and Campylobacter spp. in Northern Elephant Seals, California

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    Campylobacter and Salmonella spp. prevalence and antimicrobial drug sensitivity were determined in northern elephant seals that had not entered the water and seals that were stranded on the California coast. Stranded seals had a higher prevalence of pathogenic bacteria, possibly from terrestrial sources, which were more likely to be resistant

    Factors contributing to delays in diagnosis of breast cancers in Ghana, West Africa

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    BACKGROUND: Late diagnoses and poor prognoses of breast cancer are common throughout Africa. METHODS: To identify responsible factors, we utilized data from a population-based case-control study involving 1,184 women with breast malignancies conducted in three hospitals in Accra and Kumasi, Ghana. Interviews focused on potential breast cancer risk factors as well as factors that might contribute to presentation delays. We calculated odds ratios (OR) and 95% confidence intervals (CI) comparing malignances with biopsy masses larger than 5 cm. (62.4% of the 1,027 cases with measurable lesions) to smaller lesions. RESULTS: In multivariate analyses, strong predictors of larger masses were limited education (OR=1.96, 95% CI 1.32–2.90 <primary vs. ≥senior secondary school), being separated/divorced or widowed (1.75, 1.18–2.60 and 2.25, 1.43–3.55, respectively, vs. currently married), delay in care seeking after onset of symptoms (2.64, 1.77–3.95 for ≥12 vs. ≤2 months), care having initially been sought from someone other than a doctor/nurse (1.86, 0.85–4.09), and frequent use of herbal medications/treatment (1.51, 0.95–2.43 for ≥3x/day usage vs. none),. Particularly high risks associated with these factors were found among less educated women; for example, women with less than junior secondary schooling who delayed seeking care for breast symptoms for 6 months or longer were at nearly 4-times the risk of more educated women who promptly sought assistance. CONCLUSIONS: Our findings suggest that additional communication, particularly among less educated women, could promote earlier breast cancer diagnoses. Involvement of individuals other than medical practitioners, including traditional healers, may be helpful in this process

    Clinicopathologic characteristics of early-onset breast cancer: a comparative analysis of cases from across Ghana

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    BACKGROUND: Breast cancer is the commonest cancer diagnosed globally and the second leading cause of cancer-related mortality among women younger than 40 years. This study comparatively reviewed the demographic, pathologic and molecular features of Early-Onset Breast Cancer (EOBC) reported in Ghana in relation to Late Onset Breast Cancer (LOBC). METHODS: A descriptive, cross-sectional design was used, with purposive sampling of retrospective histopathology data from 2019 to 2021. Reports of core or incision biopsy, Wide Local Excision or Mastectomy with or without axillary lymph node dissection specimen and matched immunohistochemistry reports were merged into a single file and analysed with SPSS v. 20.0. Descriptive statistics of frequencies and percentages were used to describe categorical variables. Cross-tabulation and chi-square test was done at a 95% confidence interval with significance established at p \u3c 0.05. RESULTS: A total of 2418 cases were included in the study with 20.2% (488 cases) being EOBCs and 79.8% (1930 cases) being LOBCs. The median age at diagnosis was 34.66 (IQR: 5.55) in the EOBC group (\u3c 40 years) and 54.29 (IQR: 16.86) in the LOBC group (≥ 40 years). Invasive carcinoma-No Special Type was the commonest tumour type with grade III tumours being the commonest in both categories of patients. Perineural invasion was the only statistically significant pathologic parameter with age. EOBC was associated with higher DCIS component (24.8% vs 21.6%), lower hormone-receptor-positive status (52.30% vs 55.70%), higher proliferation index (Ki-67 \u3e 20: 82.40% vs 80.30%) and a higher number of involved lymph nodes (13.80% vs 9.00%). Triple-Negative Breast cancer (26.40% vs 24.30%) was the most predominant molecular subtype of EOBC. CONCLUSION: EOBCs in our setting are generally more aggressive with poorer prognostic histopathological and molecular features when compared with LOBCs. A larger study is recommended to identify the association between relevant pathological features and early onset breast cancer in Ghana. Again, further molecular and genetic studies to understand the molecular genetic drivers of the general poorer pathological features of EOBCs and its relation to patient outcome in our setting is needed

    Protective Effects of Human iPS-Derived Retinal Pigment Epithelium Cell Transplantation in the Retinal Dystrophic Rat

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    Transformation of somatic cells with a set of embryonic transcription factors produces cells with the pluripotent properties of embryonic stem cells (ESCs). These induced pluripotent stem (iPS) cells have the potential to differentiate into any cell type, making them a potential source from which to produce cells as a therapeutic platform for the treatment of a wide range of diseases. In many forms of human retinal disease, including age-related macular degeneration (AMD), the underlying pathogenesis resides within the support cells of the retina, the retinal pigment epithelium (RPE). As a monolayer of cells critical to photoreceptor function and survival, the RPE is an ideally accessible target for cellular therapy. Here we report the differentiation of human iPS cells into RPE. We found that differentiated iPS-RPE cells were morphologically similar to, and expressed numerous markers of developing and mature RPE cells. iPS-RPE are capable of phagocytosing photoreceptor material, in vitro and in vivo following transplantation into the Royal College of Surgeons (RCS) dystrophic rat. Our results demonstrate that iPS cells can be differentiated into functional iPS-RPE and that transplantation of these cells can facilitate the short-term maintenance of photoreceptors through phagocytosis of photoreceptor outer segments. Long-term visual function is maintained in this model of retinal disease even though the xenografted cells are eventually lost, suggesting a secondary protective host cellular response. These findings have identified an alternative source of replacement tissue for use in human retinal cellular therapies, and provide a new in vitro cellular model system in which to study RPE diseases affecting human patients
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