Off-line vs. On-line Evaluation of Recommender Systems in Small E-commerce

In this paper, we present our work towards comparing on-line and off-line evaluation metrics in the context of small e-commerce recommender systems. Recommending on small e-commerce enterprises is rather challenging due to the lower volume of interactions and low user loyalty, rarely extending beyond a single session. On the other hand, we usually have to deal with lower volumes of objects, which are easier to discover by users through various browsing/searching GUIs. The main goal of this paper is to determine applicability of off-line evaluation metrics in learning true usability of recommender systems (evaluated on-line in A/B testing). In total 800 variants of recommending algorithms were evaluated off-line w.r.t. 18 metrics covering rating-based, ranking-based, novelty and diversity evaluation. The off-line results were afterwards compared with on-line evaluation of 12 selected recommender variants and based on the results, we tried to learn and utilize an off-line to on-line results prediction model. Off-line results shown a great variance in performance w.r.t. different metrics with the Pareto front covering 68\% of the approaches. Furthermore, we observed that on-line results are considerably affected by the novelty of users. On-line metrics correlates positively with ranking-based metrics (AUC, MRR, nDCG) for novice users, while too high values of diversity and novelty had a negative impact on the on-line results for them. For users with more visited items, however, the diversity became more important, while ranking-based metrics relevance gradually decrease.Comment: Submitted to ACM Hypertext 2020 Conferenc

Evaluating the Performance of Saudi Commercial Banks Using CAMELS Methodology

This study aims to evaluate the Saudi commercial banks performance using CAMELS methodology with a sample of 12 Saudi commercial banks listed on the Saudi Stock Exchange during the period 2010-2016.The study measures the performance by calculating the rate of return on assets, while the independent variables included elements of the CAMELS model, in addition to the rate of growth, inflation and the bank size.The study results show that capital adequacy, asset quality, management efficiency, and profitability have a statistically significant positive impact on the performance of Saudi commercial banks. Liquidity and market risk sensitivity were a significant negative impact on the performance of Saudi commercial banks. As well, growth and volume had a positive and statistically significant impact while inflation had a negative and statistically significant impact on the banks performance. The study recommends increasing attention to the preparation of training courses in the evaluation of banks using the CAMELS model in order to develop regulatory systems. The study also recommends that SAMA should make more efforts to reduce non-performing loans Keywords: Return on Assets, Inflation, Growth, CAMELS Model. DOI: 10.7176/RJFA/10-12-12 Publication date:June 30th 201

Development and evaluation of low-volume tests to detect and characterize antibodies to SARS-CoV-2

Low-volume antibody assays can be used to track SARS-CoV-2 infection rates in settings where active testing for virus is limited and remote sampling is optimal. We developed 12 ELISAs detecting total or antibody isotypes to SARS-CoV-2 nucleocapsid, spike protein or its receptor binding domain (RBD), 3 anti-RBD isotype specific luciferase immunoprecipitation system (LIPS) assays and a novel Spike-RBD bridging LIPS total-antibody assay. We utilized pre-pandemic (n=984) and confirmed/suspected recent COVID-19 sera taken pre-vaccination rollout in 2020 (n=269). Assays measuring total antibody discriminated best between pre-pandemic and COVID-19 sera and were selected for diagnostic evaluation. In the blind evaluation, two of these assays (Spike Pan ELISA and Spike-RBD Bridging LIPS assay) demonstrated >97% specificity and >92% sensitivity for samples from COVID-19 patients taken >21 days post symptom onset or PCR test. These assays offered better sensitivity for the detection of COVID-19 cases than a commercial assay which requires 100-fold larger serum volumes. This study demonstrates that low-volume in-house antibody assays can provide good diagnostic performance, and highlights the importance of using well-characterized samples and controls for all stages of assay development and evaluation. These cost-effective assays may be particularly useful for seroprevalence studies in low and middle-income countries

Left and right ventricle assessment with Cardiac CT: validation study vs. Cardiac MR

Objectives To compare Magnetic Resonance (MR) and Computed Tomography (CT) for the assessment of left (LV) and right (RV) ventricular functional parameters. Methods Seventy nine patients underwent both Cardiac CT and Cardiac MR. Images were acquired using short axis (SAX) reconstructions for CT and 2D cine b-SSFP (balanced- steady state free precession) SAX sequence for MR, and evaluated using dedicated software. Results CT and MR images showed good agreement: LV EF (Ejection Fraction) (52±14% for CT vs. 52±14% for MR; r0 0.73; p>0.05); RV EF (47±12% for CT vs. 47±12% for MR; r00.74; p>0.05); LV EDV (End Diastolic Volume) (74± 21 ml/m 2 for CT vs. 76±25 ml/m 2 for MR; r00.59; p>0.05); RV EDV (84±25 ml/m 2 for CT vs. 80±23 ml/m 2 for MR; r0 0.58; p>0.05); LV ESV (End Systolic Volume)(37±19 ml/m 2 for CT vs. 38±23 ml/m 2 for MR; r00.76; p>0.05); RV ESV (46±21 ml/m 2 for CT vs. 43±18 ml/m 2 for MR; r00.70; p>0.05). Intra- and inter-observer variability were good, and the performance of CT was maintained for different EF subgroups. Conclusions Cardiac CT provides accurate and reproducible LVand RV volume parameters compared with MR, and can be considered as a reliable alternative for patients who are not suitable to undergo MR. Key Points • Cardiac-CT is able to provide Left and Right Ventricular function. • Cardiac-CT is accurate as MR for LV and RV volume assessment. • Cardiac-CT can provide accurate evaluation of coronary arteries and LV and RV function

Monitoring Opioid Use in Cancer Survivors: Implementation of Screening, Brief Intervention, and Referral to Treatment (SBIRT) in a Clinical Setting

Kentucky is a disparate state, ranking as one of the top states in incidence, prevalence, and mortality for both opioid use disorders (OUD) and cancer. Due to the high volume of both diseases in the state, there is a rising concern about the overlap of these two populations. Cancer and its’ treatment are known to cause chronic pain, defined as daily pain lasting 3 months or longer. Generally, chronic pain patients of any type are known to experience higher rates of opioid misuse (21-28%) and opioid dependence (8-12%) than the general population (4.1%, 0.9% respectively). The risk of OUD must be considered when initiating long-term opioid treatment for chronic pain, since a substance use disorder may result in poor pain control, dysimmune effects, and tumor proliferative effects. This program will utilize a transdisciplinary team approach to implement Screening, Brief Intervention, and Referral to Treatment (SBIRT) at the University of Kentucky Markey Cancer Center (UK MCC) in Lexington, KY to assess cancer survivors’ risk for developing OUD, monitor opioid use during the first 12-months of survivorship, and refer patients to alternative therapies to reduce reliance on opioids and improve pain management. The implementation of the program will be evaluated with a process evaluation and an outcome evaluation. Process evaluation metrics for the provider include: performance on trainings; administration of assessments, opioid monitoring measures, and pain scales; and rate of opioid prescriptions. Outcome evaluation metrics for the participant include: ability to manage pain; satisfaction with pain treatment plans; rate of completed referrals to specialists; change in OUD monitoring measure scores and number completed; and rate of opioid prescriptions. The program will utilize existing resources through UK Healthcare, the MCC Affiliate Network, and the MCC Research Network to implement the program to scale and disseminate findings across the state and to stakeholders

HybridAlpha: An Efficient Approach for Privacy-Preserving Federated Learning

Federated learning has emerged as a promising approach for collaborative and privacy-preserving learning. Participants in a federated learning process cooperatively train a model by exchanging model parameters instead of the actual training data, which they might want to keep private. However, parameter interaction and the resulting model still might disclose information about the training data used. To address these privacy concerns, several approaches have been proposed based on differential privacy and secure multiparty computation (SMC), among others. They often result in large communication overhead and slow training time. In this paper, we propose HybridAlpha, an approach for privacy-preserving federated learning employing an SMC protocol based on functional encryption. This protocol is simple, efficient and resilient to participants dropping out. We evaluate our approach regarding the training time and data volume exchanged using a federated learning process to train a CNN on the MNIST data set. Evaluation against existing crypto-based SMC solutions shows that HybridAlpha can reduce the training time by 68% and data transfer volume by 92% on average while providing the same model performance and privacy guarantees as the existing solutions.Comment: 12 pages, AISec 201

Stereotactic Body Radiation Therapy Is Effective and Safe in Patients with Early-Stage Non-Small Cell Lung Cancer with Low Performance Status and Severe Comorbidity

Background: The purpose of this study was to assess stereotactic body radiation therapy (SBRT) results and toxicity for stage I non-small cell lung cancer patients with low performance status and severe comorbidity. Patients and Methods: From September 2008 to April 2010, 36 patients with 38 lesions were treated with hypofractionated SBRT. All except one were medically inoperable, had low performance status and/or severe cardiovascular and/or cardiopulmonary comorbidity. The patients were immobilized in an Elekta stereotactic body frame to improve setup accuracy, and four-dimensional CT scans were used for target delineation. Fractions of 15 Gy were prescribed to cover the planning target volume, giving a total dose of 45 Gy, with 1 fraction every second day. Cone beam CT was applied at each fraction to correct for setup errors. The patients were followed with toxicity evaluation and radiographic follow-up. Results: Median follow-up time was 13.8 months (0–21 months). The local tumor control after 12 months was 100%. Four patients developed regional relapse about 12 months after SBRT. The 1-year disease-free survival was 83%. The median tumor shrinkage at 1 year was 22 mm. Three patients experienced systemic relapse after 13 months. One patient developed grade 3 chest pain toxicity and 16 patients reported temporary grade 1 chest pain toxicity. Two patients reported temporary increased dyspnea. No patient experienced a reduction of the performance status after SBRT. Conclusion: SBRT is an effective and safe treatment modality for elderly patients with early-stage non-small cell lung cancer, having low performance status and severe comorbidity. It is possible to achieve high local control rates with good tolerance