68 research outputs found
COVID-19 mandated self-directed distance learning: Experiences of Saudi female postgraduate students
Since the emergence of the 2020 coronavirus (COVID-19) pandemic, Saudi Arabia (SA) has preserved the safety of its citizens by mandating crisis distance education (CDE). Appreciating that most learners struggle with such an abrupt shift in delivery mode, especially one that depends on self-directed learning (SDL), this exploratory, qualitative study solicited data in May 2020 from a convenience sample of 20 Saudi female postgraduate students enrolled at a public university in the Eastern Province of SA. Findings affirmed that SDL via CDE contributed to their educational growth, and they will continue to engage with SDL after the health crisis ends. In short, their SDL CDE experience changed the way they will approach their education in the future. Their high level of SDL allowed them to assume responsibility for their learning. They especially gained an appreciation for the role of reflection, self-monitoring, and self-evaluation. SDL both instilled and promoted self-confidence, self-reliance, commitment, and perseverance. Implications for future research were tendered and universities are encouraged to intentionally build learning environments that support learner-centered and self-directed learning to move the country through and beyond the COVID 19 pandemic
Pre-service Teachers’ Preferred Methods of Assessment: A Perspective from Saudi Arabia
Teacher-candidate course assessment is one topic that has not been adequately explored in teacher education literature where pre-service teachers’ voices are rarely heard. Assessment methods in pre-service teacher programs across the world, including in Saudi Arabia, have received little exploration in the literature. This mixed-methods study explored a group of female pre-service teachers (n = 83) enrolled in a Diploma of Education program to identify their preferred method of assessment for their learning. The results showed that these individuals preferred a group assignment, consisting of a written report and an oral presentation, over an individual assignment, consisting of an individual essay, because the group assignment helped them to break through the boundary of facing an audience and encouraged them to exchange knowledge with their counterparts
The New Dagum-X Family of Distributions: Properties and Applications
Various statistical distributions are still being used extensively over the previous decades for modeling data in numerous areas such as engineering, sciences, and finance. Nonetheless, in a lot of applied areas, there is a continuous need for expanded forms of these distributions. However, many common distributions do not fit the data well. Thus, new distributions have been constructed in literature. The purpose of this article is to present a new family of distributions using the Dagum distribution as a generator and to study its properties such as hazard rate functions, moments, quantile function, ordered statistics and Renyi entropy. Moreover, one sub model called Dagum-Frechet distribution is discussed with some of its properties. The maximum likelihood estimation is employed to estimate the parameters of the proposed distribution, and the confidence intervals are obtained. Finally, two real data sets are analyzed to illustrate the performance of the purposed distribution
Statistical Inference for the Transformed Rayleigh Lomax Distribution with Progressive Type-II Right Censorship
In this paper, we study the transformed Rayleigh Lomax (Trans-RL) distribution which belongs to a certain family of two parameters lifetime distributions given by Wang et al (2010). Confidence intervals and inverse estimators of the Trans-RL parameters are derived in terms of order statistics. A simulation study is conducted to report the coverage probabilities, the average biases and the average relative mean square errors for the maximum likelihood, L-moments and inverse estimators. We compare the performance of these methods under different schemes of progressively Type-II right censoring. Finally, an illustrative example is provided to demonstrate the proposed methods
The Effectiveness of the Summer Immersion Program for Developing Time Management and Metacognitive Thinking Life Skills among Female Secondary School Students in Saudi Arabia
This research aimed at examining the effectiveness of the Saudi Aramco Research Science Initiative (SARSI) Summer Immersion training program for developing time management and meta cognitive thinking life skills among female gifted secondary school students. The research sample comprised 31 female gifted students enrolled in various Saudi secondary schools. Their ages ranged from 15 to 17 years old with an average age of 16.23. The Abdul Salam scale was used for the measuring time-management performance and metacognitive thinking skills in the pre- and post-assessment of the SARSI program. Statistical analysis revealed significant differences between the students’ pre- and post-assessments on: a) time management skills; b) the overall meta cognitive thinking life skills and  c) two subcategories of metacognitive skills: planning and self-monitoring. However, no significant differences were identified in the pre- and post-assessment for self-assessment
Evaluating Teaching Strategies in Higher Education From Students\u27 Perspectives
This study was conducted to investigate students\u27 perception of learning experiences at one of the largest government universities in the eastern province of Saudi Arabia. The sample consisted of male and female students and their instructors enrolled in four main colleges (Arts, Education, Preparatory year, and Science). Data were collected through a survey and focus group interviews during the fall semester of 2014-2015 academic year. The results provide feedback to faculty members about the quality of content, format, and structure of their courses, and can contribute to teaching and learning processes by facilitating faculty growth, development, and self-improvement
Microscopic Characterization of Mineral Dissolution and Precipitation at Variable Salinity for Improved Oil Recovery in Carbonate Reservoirs
Aging of carbonate mineral surfaces in brines of variable salinity and crude oil leads to massive transformations of surface topography and chemical composition including the formation of mixed organic-inorganic interfacial layers. The response of these interfacial layers to variations in brine composition is responsible for local (chemical) wettability alteration and therefore becomes the main microscopic driver for improved oil recovery in low-salinity water flooding or SmartWater flooding. In this study, a new method was developed to directly visualize local nanoscale dissolution and (re)precipitation around the three-phase contact line on model calcite surfaces in the presence of crude oil and ambient brine upon aging. The sessile microscopic oil drops on calcite surfaces were exposed to brines of variable composition at room temperature (22 °C) and at elevated temperatures (95 °C) for up to 2 weeks. Brines ranged from hypersaline formation water to diluted high-salinity water, in part enriched with Mg2+ or SO42- ions. In situ optical and ex situ atomic force microscopy (AFM) imaging of the calcite surfaces was performed prior to and after aging, complemented by confocal Raman imaging. Optical images show that crude oil drops remained attached to the mineral surfaces throughout all aging procedures studied and displayed only occasional minor relaxations of their shape at elevated temperatures. Ex situ AFM images after calcite cleaning and drying displayed strong marks of the original droplet positions that appeared either as holes or as protruding mesas with respect to the surrounding surface level, with height differences up to several hundred nanometers. The sessile oil drops are thus found to protect the underlying calcite surface from both precipitation and dissolution, in overall agreement with the macroscopic calcite saturation of the brines. The qualitative trends are consistent for all conditions investigated, notwithstanding a higher degree of variability at elevated temperatures and upon preaging in oil-equilibrated formation water. In contrast to the calcite-brine interface that undergoes these massive transformations, the oil-calcite interface remains overall remarkably inert. Only at 95 °C does the occasional appearance of roundish rims accompanied by hillocks suggest the growth of water drops during aging, possibly via exchange across thin aqueous layers.</p
Clinical epidemiology of venous thromboembolic disease: An institutional registry
IntroductionVenous thromboembolism (VTE) is a major health concern, with an annual incidence of ~1 in 1,000. The epidemiology of VTE in Saudi Arabia has not been adequately described yet. Therefore, this study aimed to assess the clinical characteristics, risk factors, diagnostic methods, management, and clinical outcomes of patients with VTE.MethodsThis study was based on a VTE registry created over ten years at King Fahad Medical City (KFMC) in Riyadh, Saudi Arabia. All adult inpatients and outpatients referred to the thrombosis unit of the KFMC with clinically suspected VTE including pulmonary embolism (PE) and deep vein thrombosis (DVT) were enrolled. Data were collected using a standardized case report form, which included demographic and clinical characteristics, risk factors, diagnostic methods, management, and outcomes.ResultsA total of 1,008 patients were recruited. Most patients were women (73.2%), and more than half of all patients had unprovoked VTE (58%). Among the provoked cases, the most frequent cause was surgery (29.8%), followed by hospitalization (24.2%). There was a significant statistical association between provoked status and sex, family history of VTE, smoking, recent hospitalization within 3 months for a medical condition, the site of VTE, and underlying peripheral vascular disease and varicose veins (all p < 0.05). The majority (88.3%) of patients with deep vein thrombosis was hospitalized for ≤3 days (n = 433, 79.9%), while fewer than half of the patients with PE needed hospitalization (45.3%). Thrombolytic therapy was administered to 14.1% (n = 142) of patients, and catheter-directed thrombolysis was performed in 1.0% (n = 10) of patients. The odds of mortality for provoked VTE were 3.20 times higher than those of unprovoked VTE [2.12–4.83; p-value < 0.001].ConclusionUnprovoked VTE was more common than provoked VTE in the Saudi Arabian cohort, implying hereditary predisposition. Furthermore, male sex, family history of VTE, prior history of VTE, type of VTE, underlying obesity, history of trauma, surgery, hospitalization, pregnancy, and 3–6 months of anticoagulation therapy were the most critical risk factors for VTE recurrence. The treatment patterns and clinical results were comparable to those reported in the literature
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