A reinforcement learning recommender system using bi-clustering and Markov Decision Process

Collaborative filtering (CF) recommender systems are static in nature and does not adapt well with changing user preferences. User preferences may change after interaction with a system or after buying a product. Conventional CF clustering algorithms only identifies the distribution of patterns and hidden correlations globally. However, the impossibility of discovering local patterns by these algorithms, headed to the popularization of bi-clustering algorithms. Bi-clustering algorithms can analyze all dataset dimensions simultaneously and consequently, discover local patterns that deliver a better understanding of the underlying hidden correlations. In this paper, we modelled the recommendation problem as a sequential decision-making problem using Markov Decision Processes (MDP). To perform state representation for MDP, we first converted user-item votings matrix to a binary matrix. Then we performed bi-clustering on this binary matrix to determine a subset of similar rows and columns. A bi-cluster merging algorithm is designed to merge similar and overlapping bi-clusters. These bi-clusters are then mapped to a squared grid (SG). RL is applied on this SG to determine best policy to give recommendation to users. Start state is determined using Improved Triangle Similarity (ITR similarity measure. Reward function is computed as grid state overlapping in terms of users and items in current and prospective next state. A thorough comparative analysis was conducted, encompassing a diverse array of methodologies, including RL-based, pure Collaborative Filtering (CF), and clustering methods. The results demonstrate that our proposed method outperforms its competitors in terms of precision, recall, and optimal policy learning

Acute Appendicitis among Saudi and Non-Saudi Patients: A Cross-Sectional Based Study

Objective: We conduct this study to discuss the differences between Saudi and non- Saudi patients with acute appendicitis.Background: Acute appendicitis is one of emergency surgeries in developing and developed countries. Its symptoms are vomiting, lower abdominal pain and decreased appetite. Appendicitis needs urgent surgical prouder to avoid its perforation and associated complications which may lead to death. Method: We conduct cross-sectional based study in one of khamis Mushayt, Saudi Araba. 136 patients diagnosed with acute appendicitis were included and their medical records were reviewed after getting their informed consent.Results: We included 136 patients, 90 were non-Saudi and 46 were Saudi. There were no statistically differences in their diagnosis but the distribution of the diagnosis was different.Conclusion: Acute appendicitis was more prevalent among non-Saudi patients, the diagnosis between both was with no significant differences. Keywords: acute appendicitis, Saudi, non-Saudi, diagnosis, cross-sectional, Saudi Arabia and khamis Mushayt

Magnetic and microwave properties of SrFe12O19/MCe0.04Fe1.96O4 (M = Cu, Ni, Mn, Co and Zn) hard/soft nanocomposites

This paper reports the synthesis, structural characteristics and magnetism of SrFe12O19/MCe0.04Fe1.96O4 (M = Cu, Ni, Mn, Co and Zn) hard/soft nanocomposites. The hard/soft compositions were manufactured via a one-pot reactions citrate sol-gel approach. The hard/soft phases formation was confirmed using XRD, SEM, TEM and HRTEM techniques. M vs. H (Magnetization measurements) were done at unbent temperature and 10 K. Smoothed M against H loops and single peaks in dM/dH vs. H curves were noticed in SrFe12O19/MnCe0.04Fe1.96O4, SrFe12O19/CuCe0.04Fe1.96O4 and SrFe12O19/ZnCe0.04Fe1.96O4 hard/soft nanocomposites. This indicated the manifestation of well exchange-coupled effect among hard and soft phases in these composites. However, SrFe12O19/CoCe0.04Fe1.96O4 and SrFe12O19/NiCe0.04Fe1.96O4 hard/soft nanocomposites showed non-well smoothed M against H loops and two peaks in dM/dH versus H plots, indicating that the dipolar interactions are unimportant compared to exchange-coupling behavior. Among all prepared nanocomposites, the SrFe12O19/MnCe0.04Fe1.96O4 hard/soft nanocomposite showed the highest exchange-coupling behavior. Microwave properties of the SrFe12O19/MCe0.04Fe1.96O4 (M = Cu, Ni, Mn, Co and Zn) hard/soft nanocomposites were investigated using coaxial method with applied frequency values fall between 2 and 18 GHz. Reflection losses were calculated from frequency dependences of the imaginary and real parts of permeability and permittivity. The correlation between the chemical composition of the spinel phase (A-cation) and microwave properties of composites. Most intensive electromagnetic absorption was observed for Ni- and Mn-spinels. This is can be a result of the differences in electron shell configuration and radii for A-site ions in the spinel phase. Change of the absorption mechanisms (transition from ionic polarization to dipole polarization) was observed. © 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).The work was supported by the Russian Science Foundation (agreement number 19-72-10071 ). Also Authors are thank to the Institute for Research & Medical Consultations (Projects Application No. 2018-IRMC-S-2 ) of Imam Abdulrahman Bin Faisal University (IAU – Saudi Arabia) for financial and technical supports

A nationwide survey of public COPD knowledge and awareness in Saudi Arabia: A population-based survey of 15,000 adults

BACKGROUND: There is a concerning lack of representative data on chronic obstructive pulmonary disease (COPD) awareness in Saudi Arabia, and a significant proportion of the population is vulnerable to developing a smoking habit, which is a major risk factor for the disease. METHODS: Population-Based Survey of 15,000 people was conducted to assess the public knowledge and awareness of COPD across Saudi Arabia from October 2022 to March 2023. RESULTS: A total of 15002 responders completed the survey, with a completion rate of 82%. The majority 10314 (69%) were 18–30 year and 6112 (41%) had high school education. The most common comorbidities among the responders were depression (7.67%); hypertension (6%); diabetes (5.77%) and Chronic Lung Disease (4.12%). The most common symptoms were dyspnea (17.80%); chest tightness (14.09%) and sputum (11.19%). Among those who complains of any symptoms, only 16.44% had consulted their doctor. Around 14.16% were diagnosed with a respiratory disease and only 15.56% had performed pulmonary function test (PFT). The prevalence of smoking history was 15.16%, in which current smokers were 9.09%. About 48% of smokers used cigarette, 25% used waterpipe and around 27% were E-cigarette users. About 77% of the total sample have never heard about COPD. Majority of current smokers (73.5%; 1002), ex-smokers (68%; 619), and non-smokers (77.9%; 9911) are unaware of COPD, p value <0.001. Seventy five percent (1028) of the current smokers and 70% (633) of the ex-smokers have never performed PFT, p value <0.001. Male, younger age (18–30 years), higher education, family history of respiratory diseases, previous diagnosis of respiratory disease, previous PFT, and being an ex-smokers increases the odds of COPD awareness, p-value <0.05. CONCLUSION: There is a significantly low awareness about COPD in Saudi Arabia, especially among smokers. A nationwide approach must include targeted public awareness campaigns, continued healthcare professional education, community-based activities encouraging diagnosis and early detection, advice on smoking cessation and lifestyle changes, as well as coordinated national COPD screening programs

A population-based study of 15,000 people on Knowledge and awareness of lung cancer symptoms and risk factors in Saudi Arabia

Background: Lung cancer is currently the most fatal form of cancer worldwide, ranking as the fourth most prevalent type in Saudi Arabia, particularly among males. This trend is expected to increase with growing population, lifestyle changes, and aging population. Understanding the awareness of the Saudi population regarding the risk factors and symptoms of lung cancer is necessary to attenuate the predicted increase in cases. Method: A cross-sectional, population-based survey was performed using a previously validated questionnaire (Lung CAM). Multiple linear regression analysis was used to assess variables associated with deficiency in knowledge and awareness of risk factors and symptoms of lung cancer. Results: Majority of the 15,099 respondents were male (65%), aged between 18 and 30 years (53%), 50% of which were educated up to a bachelor’s degree level. Overall awareness of lung cancer signs and symptoms was 53%, with painful cough and coughing up blood being the best-known symptoms. Conversely, persistent shoulder pain (44%) and clubbing fingers (47%) were the least known lung cancer symptoms. Also, 60% of the respondents showed low confidence in identifying the signs and symptoms of lung cancer. The overall awareness of the risk factors for lung cancer development was 74%, with first-hand (74%) and second-hand (68%) smoking being the most known risk factors. However, only ≤ 62% know the other non-smoking risk factors. Awareness of the risk factors and symptoms of lung cancer depended on age, gender, education, marital and employment status (p &lt; 0.001). Conclusion: Public awareness of the risk factors and symptoms of lung cancer in Saudi Arabia is inadequate and heavily dependent on education and socio-economic status. Awareness can be improved through campaigns to raise awareness about other lesser-known lung cancer risk factors and symptoms

A population-based study of 15,000 people on Knowledge and awareness of lung cancer symptoms and risk factors in Saudi Arabia

Background: Lung cancer is currently the most fatal form of cancer worldwide, ranking as the fourth most prevalent type in Saudi Arabia, particularly among males. This trend is expected to increase with growing population, lifestyle changes, and aging population. Understanding the awareness of the Saudi population regarding the risk factors and symptoms of lung cancer is necessary to attenuate the predicted increase in cases. Method: A cross-sectional, population-based survey was performed using a previously validated questionnaire (Lung CAM). Multiple linear regression analysis was used to assess variables associated with deficiency in knowledge and awareness of risk factors and symptoms of lung cancer. Results: Majority of the 15,099 respondents were male (65%), aged between 18 and 30 years (53%), 50% of which were educated up to a bachelor’s degree level. Overall awareness of lung cancer signs and symptoms was 53%, with painful cough and coughing up blood being the best-known symptoms. Conversely, persistent shoulder pain (44%) and clubbing fingers (47%) were the least known lung cancer symptoms. Also, 60% of the respondents showed low confidence in identifying the signs and symptoms of lung cancer. The overall awareness of the risk factors for lung cancer development was 74%, with first-hand (74%) and second-hand (68%) smoking being the most known risk factors. However, only ≤ 62% know the other non-smoking risk factors. Awareness of the risk factors and symptoms of lung cancer depended on age, gender, education, marital and employment status (p &lt; 0.001). Conclusion: Public awareness of the risk factors and symptoms of lung cancer in Saudi Arabia is inadequate and heavily dependent on education and socio-economic status. Awareness can be improved through campaigns to raise awareness about other lesser-known lung cancer risk factors and symptoms

Laser Vaporization of Mouth Lesions, an Overview

Lasers are utilized in dentistry as a therapeutic tool or as an auxiliary tool. The major purpose of employing lasers in dentistry is to overcome the difficulties that are currently observed in traditional dental treatment treatments. The laser is used in hard tissue applications such as caries prevention, bleaching, restorative removal and curing, cavity preparation, dentinal hypersensitivity, growth modulation, and diagnostics, whereas soft tissue applications include wound healing, removal of hyperplastic tissue to uncover impacted or partially erupted teeth, photodynamic therapy for malignancies, and photo-stimulation of herpetic lesions. Lasers' capacity to perform minimally invasive operations with minimum patient discomfort has proven effective in the patient delivery system in dentistry practice. The availability of lasers with various wavelengths has produced a surgical panacea, and laser technology has replaced traditional surgical techniques in many oral surgical operations

Perspectives, practices, and challenges of online teaching during COVID-19 pandemic: A multinational survey

The result of the movement restrictions during the COVID-19 pandemic was an impromptu and abrupt switch from in-person to online teaching. Most focus has been on the perception and experience of students during the process. The aim of this international survey is to assess staffs' perspectives and challenges of online teaching during the COVID-19 lockdown. Cross-sectional research using a validated online survey was carried out in seven countries (Brazil, Saudi Arabia, Jordan, Indonesia, India, the United Kingdom, and Egypt) between the months of December 2021 and August 2022, to explore the status of online teaching among faculty members during the COVID-19 pandemic. Variables and response are presented as percentages while logistic regression was used to assess the factors that predict levels of satisfaction and the challenges associated with online instruction. A total of 721 response were received from mainly male (53%) staffs. Most respondents are from Brazil (59%), hold a Doctorate degree (70%) and have over 10 years of working experience (62%). Although, 67% and 79% have relevant tools and received training for online teaching respectively, 44% report that online teaching required more preparation time than face-to-face. Although 41% of respondents were uncertain about the outcome of online teaching, 49% were satisfied with the process. Also, poor internet bandwidth (51%), inability to track students' engagement (18%) and Lack of technical skills (11.5%) were the three main observed limitations. Having little or no prior experience of online teaching before the COVID-19 pandemic [OR, 1.58 (95% CI, 1.35–1.85)], and not supporting the move to online teaching mode [OR, 0.56 (95% CI,0.48–0.64)] were two main factors independently linked with dissatisfaction with online teaching. While staffs who support the move to online teaching were twice likely to report no barriers [OR, 2.15 (95% CI, 1.61–2.86)]. Although, relevant tools and training were provided to support the move to online teaching during COVID-19 lockdown, barriers such as poor internet bandwidth, inability to track students’ engagement and lack of technical skills were main limitations observed internationally by teaching staffs. Addressing these barriers should be the focus of higher education institution in preparation for future disruptions to traditional teaching modes

Effectiveness and safety of edoxaban versus warfarin in patients with nonvalvular atrial fibrillation: a systematic review and meta-analysis of observational studies

Background: Atrial fibrillation (AF) is the most prevalent cardiac arrhythmia type. Patients with AF are often administered anticoagulants to reduce the risk of ischemic stroke due to an irregular heartbeat. We evaluated the efficacy and safety of edoxaban versus warfarin in patients with nonvalvular AF by conducting an updated meta-analysis of real-world studies.Methods: In this comprehensive meta-analysis, we searched two databases, PubMed and EMBASE, and included retrospective cohort observational studies that compared edoxaban with warfarin in patients with nonvalvular AF from 1 January 2009, to 30 September 2023. The effectiveness and safety outcomes were ischemic stroke and major bleeding, respectively. In the final analysis, six retrospective observational studies involving 87,236 patients treated with warfarin and 40,933 patients treated with edoxaban were included. To analyze the data, we used a random-effects model to calculate the hazard ratio (HR).Results: Patients treated with edoxaban had a significantly lower risk of ischemic stroke [hazard ratio (HR) = 0.66; 95% confidence interval (CI) = 0.61–0.70; p &lt; 0.0001] and major bleeding (HR = 0.58; 95% CI = 0.49–0.69; p &lt; 0.0001) than those treated with warfarin. The sensitivity analysis results for ischemic stroke and major bleeding were as follows: HR = 0.66; 95% CI = 0.61–0.70; p &lt; 0.0001 and HR = 0.58; 95% CI = 0.49–0.69; p &lt; 0.0001, respectively.Conclusion: Our findings revealed that edoxaban performed better than warfarin against major bleeding and ischemic stroke