Hybrid fuzzy inference rules of descent method and wavelet function for volatility forecasting.

This research employs the gradient descent learning (FIR.DM) approach as a learning process in a nonlinear spectral model of maximum overlapping discrete wavelet transform (MODWT) to improve volatility prediction of daily stock market prices using Saudi Arabia's stock exchange (Tadawul) data. The MODWT comprises five mathematical functions and fuzzy inference rules. The inputs are the oil price (Loil) and repo rate (Repo) according to multiple regression correlation, and the Engle and Granger Causality test Engle RF, (1987). The logarithm of the stock market price (LSCS) in Tadawul reflects the output variable. The correlation matrix reveals that there is no collinearity between the input variables, and the causality test demonstrates that the input variables significantly influence the outcome variable. According to the multiple regression, there is a substantial negative influence between Loil and LSCS but a significant positive effect between Repo and output. For the 80% dataset under ME (0.000005), MAE (0.003214), and MAPE (0.064497), the MODWT-LA8 (ARIMA(1,1,0) with drift) for the LSCS variable performs better than other WT functions. In the novel hybrid model MODWT-FIR.DM, each function's approximation coefficient (LSCS) is applied with input variables (Loil and Repo). We evaluate the performance of the proposed model (MODWT-LA8-FIR.DM) using different statistical measures (ME, RMSE, MAE, MPE) and compare it to two established models: the original FIR.DM and other MODWT-FIR.DM functions for forecasting 20% of datasets. The outcomes show that the MODWT-LA8-FIR.DM performs better than the traditional models based on lower ME (3.167586), RMSE (3.167638), MAE (3.167586), and MPE (80.860849). The proposed hybrid model may be a potential stock market forecasting model.

Traumatic Enthesophyte From a Chronic Pectoralis Major Tendon Rupture: A Case Report.

CASE: A 24-year-old active duty soldier with a chronic pectoralis major tendon rupture presented a year later with a bony lesion consistent with an enthesophyte at the humeral insertion. The patient continued to have pain that was affecting his activities of daily living and underwent surgical intervention. CONCLUSION: Operative management with enthesophyte excision and pectoralis major tendon repair provided relief to the patient's symptoms and return to preinjury levels of function as evaluated with Tegner, single assessment numeric evaluation, and visual analog scale scores at the 2-year follow-up.

A novel investigation of the influence of corporate governance on firms' credit ratings.

Corporate governance is the way of governing a firm in order to increase its accountability and to avoid any massive damage before it occurs. The aim of this paper is to investigate the impact of capital structure, firms' size, and competitive advantages of firms as control variables on credit ratings. We investigate the role of corporate governance in improving the firms' credit rating using a sample of Jordanian listed firms. We split firms into four categories according to WVB credit rating. We use both the binary logistic regression (LR) and the ordinal logistic regression (OLR) to model credit ratings in Jordanian environment. The empirical results show that the control variables are strong determinants of credit ratings. When we evaluate the relationship between the governance variables and credit ratings, we found interesting results. The board stockholders and board expertise are moderately significant. The board independence and role duality are weakly significant, while board size is insignificant.

A 5-Year History of Laparoscopic Gastric Band Removals: an Analysis of Complications and Associated Comorbidities.

OBJECTIVE: This study was undertaken to examine the factors contributing to laparoscopic adjustable gastric band (LAGB) removals among adults > 18 years of age. We hypothesized that female patients with multiple comorbidities would have increased removals. DESIGN: This retrospective exploratory study uses internal records and standard statistical methods of analysis. RESULTS: Eighty-five bands were removed (11.8% males, 88.2% females). The average BMI was 40.7 (n = 83). 2.4% of patients had removals between 0 and 12 months, 18.8% between 39 and 51 months, and 35.3% between 39 and 64 months. 8.2% of treatment times were unknown. The average treatment time was 67.9 months. 48.2% of patients had ≥ 2 comorbidities, GERD (44.2%) being the most frequent. 49.4% of patients reported dysphagia as the reason for band removal. 22.4% of removals were associated with band failures, none with port complications. The reason for band removal was unknown in 21.2% of patients. 67.1%, 32.9%, and 23.5% attended 30-, 60-, and 90-day follow-up appointments, respectively. Weight post-band removal surgery at 30, 60, and 90 days was noted to be - 0.4%., 0.9%, and 0.4%, respectively. CONCLUSION: This study supports current literature suggesting LAGB may not be an effective long-term surgical intervention for obesity. Patients with > 2 comorbidities had increased rates of removal. Dysphagia was noted to be the primary reason cited for LAGB removal. Postoperative follow-up was found to be a significant challenge for LAGB removal patients. Further study is warranted to explore if these poor follow-up rates should be considered when risk stratifying LAGB patients for revisional surgery.

Predicting success: A comparative analysis of student performance on the surgical clerkship and the NBME surgery subject exam.

BACKGROUND: The National Board of Medical Examiners surgery shelf is a well-established terminal measure of student medical knowledge. No study has explored the correlation between intraclerkship quizzes and shelf exam performance. METHODS: Weekly quiz and National Board of Medical Examiners scores were collected from 156 third-year students who participated in a 12-week surgical clerkship from 2015 to 2017. Kruskal-Wallis, Wilcoxon rank sum, and linear regression analysis was completed. RESULTS: Trauma/Burns, Esophagus/Anorectal, and Wound/Intensive Care Unit quiz content corresponded with increased National Board of Medical Examiners performance with ß-coefficients of 1.57 (P < .001), 1.42 (P < .001), 1.38 (P < .001), respectively. Wound/Intensive Care Unit and Cardio/Vascular content corresponded with decreased likelihood of scoring < 70 points on the National Board of Medical Examiners (OR: 0.75 (P = .03), and 0.68 (P = .02)). Aggregate quiz scores stratified by academic block were 67 (IQR 64-69.5), 77 (IQR 74.5-80), 76.5 (IQR of 67-89.5), 83 (IQR of 76-85) corresponding to academic blocks 1, 2, 3, and 4, respectively (P < .001). CONCLUSION: Modeling National Board of Medical Examiners outcomes as a function of weekly quizzes taken during a 12-week surgery clerkship is a viable concept.