Candidate Set Sampling for Evaluating Top-N Recommendation

The strategy for selecting candidate sets -- the set of items that the recommendation system is expected to rank for each user -- is an important decision in carrying out an offline top-$N$ recommender system evaluation. The set of candidates is composed of the union of the user's test items and an arbitrary number of non-relevant items that we refer to as decoys. Previous studies have aimed to understand the effect of different candidate set sizes and selection strategies on evaluation. In this paper, we extend this knowledge by studying the specific interaction of candidate set selection strategies with popularity bias, and use simulation to assess whether sampled candidate sets result in metric estimates that are less biased with respect to the true metric values under complete data that is typically unavailable in ordinary experiments

Effect of Maternal Alcohol Consumption on Epididymal Growth in Neonatal Mice

A study was conducted to determine the effect of maternal alcohol consumption on the growth of epididymis in neonatal mice. Three groups of adult female mice were used. The pups of group 1 served as control while the pups of groups 2 and 3 were given 30% ethanol (v/v) during pregnancy and during pregnancy and lactation respectively. At 3, 4, 5 and 6 weeks of age, 10 male pups were randomly selected from each of the three groups and sacrificed. After sacrifice, the epididymis were dissected out and theirweights determined. The results of the study showed significant decrease in the weights and growth rates of the epididymis of the pups exposed to alcohol when compared with the controls. The study has therefore  demonstrated that maternal alcohol intake during pregnancy and duringpregnancy and lactation affects the growth of epididymis of the neonates and that the epididymis of the neonates exposed to alcohol attempted catch-up growth with the control

Statistical Inference: The Missing Piece of RecSys Experiment Reliability Discourse

This paper calls attention to the missing component of the recommender system evaluation process: Statistical Inference. There is active research in several components of the recommender system evaluation process: selecting baselines, standardizing benchmarks, and target item sampling. However, there has not yet been significant work on the role and use of statistical inference for analyzing recommender system evaluation results. In this paper, we argue that the use of statistical inference is a key component of the evaluation process that has not been given sufficient attention. We support this argument with systematic review of recent RecSys papers to understand how statistical inference is currently being used, along with a brief survey of studies that have been done on the use of statistical inference in the information retrieval community. We present several challenges that exist for inference in recommendation experiment which buttresses the need for empirical studies to aid with appropriately selecting and applying statistical inference techniques

Incidental Finding of Benign Multicystic Peritoneal Mesothelioma: A Case Report

Introduction: Benign multicystic peritoneal mesothelioma represents a rare benign variant of peritoneal mesothelioma, with fewer than 150 cases reported to date. Malignant transformation may occur. We present a patient with an incidental finding of an intra-abdominal mass consistent with benign multicystic peritoneal mesothelioma.Case presentation: A 51 year-old male presented to the ED with traumatic injuries. During workup, calcified cystic lesions in the pelvis were incidentally noted. Final pathology favored a diagnosis of benign multicystic mesothelioma of the peritoneum. Follow-up imaging obtained three months post-operatively revealed no evidence of recurrent or metastatic disease.Conclusion: Multicystic peritoneal mesothelioma has been identified as a distinct subtype of peritoneal mesothelioma, with long-term survival achievable through the use of cytoreductive surgery and HIPEC. Although prognosis is relatively favorable, recurrence rates are high, with low potential for malignant transformation. Post-operative surveillance with routine imaging is warranted

Failure patterns and survival outcomes in triple negative breast cancer (TNBC): a 15 year comparison of 448 non-Hispanic black and white women

Purpose: Triple negative breast cancer (TNBC) is a distinct subtype of breast cancer with unique pathologic, molecular and clinical behavior. It occurs more frequently in young blacks and has been reported to have a shorter disease-free interval. We undertook this study to analyze the demographic characteristics, failure patterns, and survival outcomes in this disease. Methods: A total of 448 non-Hispanic black and white women were identified over a 15 year period from 1996 to 2011. Demographic and clinical information including age, race, menopausal status, stage, tumor characteristics, and treatments were collected. Fisher’s exact test and multivariable Cox regression were used to compare failure patterns and survival outcomes between races. Results: 49 % (n = 223) were black. 59 % patients were between 41 and 60 years, with 18 % ≤40 years. 57 % were premenopausal and 89 % had grade 3 tumors. Stage II (47 %) was most frequent stage at diagnosis followed by stage III (28 %). 32 % had lymphovascular invasion. Adjusting for age, stage, and grade, there was no difference in survival outcomes (OS, DFS, LFFS, and DFFS) between the two races. 62 (14 %) patients failed locally either in ipsilateral breast or chest wall, and 19 (4 %) failed in the regional lymphatics. Lung (18 %) was the most frequent distant failure site with <12 % each failing in brain, liver and bones. Conclusion: Failure patterns and survival outcomes did not differ by race in this large collection of TNBC cases. Lung was the predominate site of distant failure followed by brain, bone, and liver. Few patients failed in the regional lymphatics

Differences in the Tumor Microenvironment between African-American and European-American Breast Cancer Patients

Background: African-American breast cancer patients experience higher mortality rates than European-American patients despite having a lower incidence of the disease. We tested the hypothesis that intrinsic differences in the tumor biology may contribute to this cancer health disparity. Methods and Results: Using laser capture microdissection, we examined genome-wide mRNA expression specific to tumor epithelium and tumor stroma in 18 African-American and 17 European-American patients. Numerous genes were differentially expressed between these two patient groups and a two-gene signature in the tumor epithelium distinguished between them. To identify the biological processes in tumors that are different by race/ethnicity, Gene Ontology and disease association analyses were performed. Several biological processes were identified which may contribute to enhanced disease aggressiveness in African-American patients, including angiogenesis and chemotaxis. African-American tumors also contained a prominent interferon signature. The role of angiogenesis in the tumor biology of African-American

Racial disparities in treatment patterns and clinical outcomes in patients with HER2-positive metastatic breast cancer

Data characterizing demographics, treatment patterns, and clinical outcomes in black patients with human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer (MBC) are limited. registHER is a large, observational cohort study of patients (n = 1,001) with HER2-positive MBC diagnosed ≤6 months of enrollment and followed until death, disenrollment, or June 2009 (median follow-up of 27 months). Demographics, treatment patterns, and clinical outcomes were described for black (n = 126) and white patients (n = 793). Progression-free survival (PFS) following first-line therapy and overall survival (OS) were examined. Multivariate analyses adjusted for baseline and treatment factors. Black patients were more likely than white patients to be obese (body mass index ≥30), to have diabetes, and to have a history of cardiovascular disease; they were also less likely to have estrogen receptor or progesterone receptor positive disease. In patients treated with trastuzumab, the incidence of cardiac safety events (grade ≥3) was higher in black patients (10.9 %) than in white patients (7.9 %). Unadjusted median OS and PFS (months) were significantly lower in black patients than in white patients (OS: black: 27.1, 95 % confidence interval [CI] 21.3–32.1; white: 37.3, 95 % CI 34.6–41.1; PFS: black: 7.0, 95 % CI 5.7–8.2; white: 10.2, 95 % CI 9.3–11.2). The adjusted OS hazard ratio (HR) for black patients compared with white patients was 1.29 (95 % CI 1.00–1.65); adjusted PFS HR was 1.29 (95 % CI 1.05–1.59). This real-world evaluation of a large cohort of patients with HER2-positive MBC shows poorer prognostic factors and independently worse clinical outcomes in black versus white patients. Further research is needed to identify potential biologic differences that could have predictive impact for black patients or that could explain these differences