144 research outputs found

    Investigating Determinants of the Acceptance of Zoom Technology Through the Lens of GETAMEL

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    هدفت هذه الدراسة إلى استقصاء المحددات في قبول تقنية Zoom بناءً على أنموذج قبول التكنولوجيا العام الموسع للتعلم الإلكتروني (GETAMEL). تم تحليل البيانات المستقاة من دراسة استقصائية واسعة النطاق شملت (256) طالبا من طلبة الدراسات العليا في جامعة الملك خالد في المملكة العربية السعودية تم توظيفهم من خلال أخذ عينات ملائمة عبر الإنترنت من خلال نمذجة المعادلات الهيكلية. تم تحليل مجموعة البيانات باستخدام برنامج SPSS. وكشفت النتائج أن أنموذج الدراسة المستخدم يتمتع بقدرة تفسيرية عالية حيث يقوم بتفسير (%71) من التباين في النوايا السلوكية لاستخدام تقنية الـ Zoom. والعامل الأكثر أهمية هو الاتجاه نحو الاستخدام، في حين أن الفائدة المتصورة كان لها تأثير ضئيل على التنبؤ بنية الاستخدام. وأن كلا من سهولة الاستخدام والفائدة المدركة كان لهما تأثير إيجابي على الاتجاهات نحو استخدام تقنية Zoom. وكان العاملان الخارجيان الأساسيان الكفاءة الذاتية والمتعة المدركة لهما تأثير إيجابي على الفائدة المدركة، لكن المعايير الذاتية لم يكن لها تأثير كبير. واظهر التحليل ان متغير سهولة الاستخدام هو أفضل مؤشر على تصورات الطلبة للفائدة المدركة لتقنية الـ Zoom، يليه الكفاءة الذاتية. وأخيرا، تم التنبؤ بسهولة الاستخدام المدركة بشكل كبير من خلال الكفاءة الذاتية. وتعزز نتائج الدراسة الفهم فيما يتعلق بقبول تقنية الـ Zoom. ولهــذه النتيجة أهميــة خاصة للباحثين، والمطورين، والممارسين لتقنية Zoom في البيئات التعليمية.The present study aims to determine factors influencing graduate students’ intention to use Zoom technology. A questionnaire modified to conform to the General Extended Technology Acceptance Model was distributed to 256 graduate students at King Khalid University in Saudi Arabia. The results indicate that the hypothesized model was a good predictor of intention to use. About 71% of the variance of intention to use Zoom technology was explained. The model’s antecedents significantly predicted intention to use. The most crucial factor was attitude, while perceived usefulness had a negligible impact on predicting intention to use. Both perceived ease of use and perceived usefulness were found to predict students’ attitudes towards using Zoom. Self-efficacy and enjoyment were the most fundamental external factors in predicting perceived usefulness, but subjective norms had no significant effect. The best predictor of students’ perceptions of the usefulness of the Zoom technology was perceived ease of use, followed by self-efficacy. Finally, perceived ease of use was significantly predicted by self-efficacy. The findings improve understanding regarding the acceptance of Zoom. This work is of particular interest to researchers, developers, and practitioners of Zoom in educational contexts

    Simulation of ion behavior in an open three-dimensional Paul trap using a power series method

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    Simulations of the dynamics of ions trapped in a Paul trap with terms in the potential up to the order 10 have been carried out. The power series method is used to solve numerically the equations of motion of the ions. The stability diagram has been studied and the buffer gas cooling has been implemented by a Monte Carlo method. The dipole excitation was also included. The method has been applied to an existing trap and it has shown good agreement with the experimental results and previous simulations using other methods

    3D geometric morphometric analysis of tooth shape in hypodontia

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    Assessment of tooth morphology is essential in the diagnosis and management of hypodontia patients. Several techniques have been used to quantify tooth shape in hypodontia patients and these have revealed smaller tooth dimensions and anomalous tooth shapes in these patients when compared with controls. However, previous studies have mainly used 2D images and have thus provided limited information. The present study adopted a novel three-dimensional geometric morphometric technique to quantify the crown morphology and sizes of teeth of hypodontia patients and compare them with those of control patients. Allometric variations were also investigated in order to determine whether there was any association between the size and shape of teeth. Landmarks were recorded on each clinical crown of all the permanent teeth, apart from third molars, of 3D scanned study models of hypodontia and control subjects. The study sample comprised 120 hypodontia patients (40 patients with mild, 40 with moderate and 40 with severe hypodontia) and 40 age- and sex-matched controls. Procrustes superimposition was utilized to scale and superimpose the landmark coordinate data and were then subjected to principal component analysis (PCA). Subsequently, shape differences were tested statistically using multivariate statistics. Size variation was for the most part found to be significant, especially when the control subjects were compared to the hypodontia groups. The anterior teeth were more affected than the posterior. Generally speaking, the size differences became greater as the severity of the hypodontia increased. The pattern was virtually the same for both sexes. With regard to shape, most teeth were affected by the hypodontia, although the pattern was less clear. When allometry was taken into account, the pattern of size/shape relationship was found to be significant for most teeth, particularly in the anterior region, and shape differences were still significant after controlling, when possible, for allometry. It was found that the degree of variation in tooth shape was associated with the degree of severity of the hypodontia. The findings of the study therefore indicate that quantitative measurement of the tooth shape in hypodontia patients may enhance the multidisciplinary management of those patients.EThOS - Electronic Theses Online ServiceKing Khalid UniversityGBUnited Kingdo

    Use of mixed coordinates in modeling wind turbines including tubular tower

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    This paper studies the effect of the tower dynamics upon the wind turbine model by using mixed sets of rigid and/or nodal and/or modal coordinates within multibody system dynamics approach. The nodal model exhibits excellent numerical properties, especially in the case where the rotation of the rotor-blade is extremely high, and therefore, the geometric stiffness effect can not be ignored. However, the use of nodal models to describe the flexibility of large multibody systems produces huge size of coordinates and may consume massive computational time in simulation. On the other side, the dynamics of the tower as well as other components of wind turbine remain exhibit small deformations and can be modeled using Cartesian and/or reduced set of modal coordinates. The paper examines a method of using mixed sets of different coordinates in the same model, although there are differences in the scale and the physical interpretation. The equations of motion of the wind-turbine model is presented based on the floating frame of reference formulation. The mixed coordinates vector consists of three sets: Cartesian coordinates set to present the rigid body motion (nacelle and rotor bodies), elastic nodal coordinates for rotating blades, and reduced-order modal coordinates for low speed components and those that deflect by simple motion shapes (circular Tower). Experimental validation has been carried out successfully, and consequently, the proposed model can be utilized for design process, identification and health monitoring aspects.</p

    Access and utilisation of primary health care services comparing urban and rural areas of Riyadh Providence, Kingdom of Saudi Arabia

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    The Kingdom of Saudi Arabia (KSA) has seen an increase in chronic diseases. International evidence suggests that early intervention is the best approach to reduce the burden of chronic disease. However, the limited research available suggests that health care access remains unequal, with rural populations having the poorest access to and utilisation of primary health care centres and, consequently, the poorest health outcomes. This study aimed to examine the factors influencing the access to and utilisation of primary health care centres in urban and rural areas of Riyadh province of the KSA

    Overview on Epidemiology and Management of Myxedema Coma or Crisis

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    The most severe type of hypothyroidism is known as myxedema coma, which can quickly lead to death if not identified and treated aggressively. The condition known as hypothyroidism is easily detected and treated. But if ignored, it might eventually progress to myxedema coma, the most serious form of hypothyroidism. Since the majority of patients do not initially appear in a coma, the term "myxedema coma" is usually regarded as misleading. Lethargy usually progresses to stupor, which then becomes a coma with hypothermia and respiratory failure. only clinical criteria are used for diagnosis because thyroid hormone assays are unable to distinguish between simple hyperthyroidism and thyroid storm. Apart from essential medical interventions, the treatment focuses on preventing thyroid hormone production and secretion as antithyroid medications, and preventing the peripheral effects of thyroid hormone as β-blocker, glucocorticoids. The diagnosis of thyroid-stimulating hormone (TSH) in the blood is the same as that of simple hypothyroidism. As soon as a diagnosis is obtained, treatment should start right away. The majority of hospital and commercial laboratories can turnaround a TSH test in a matter of hours

    A Clinical Tool to Identify Candidates for Stress-First Myocardial Perfusion Imaging

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    Objectives: This study sought to develop a clinical model that identifies a lower-risk population for coronary artery disease that could benefit from stress-first myocardial perfusion imaging (MPI) protocols and that can be used at point of care to risk stratify patients. Background: There is an increasing interest in stress-first and stress-only imaging to reduce patient radiation exposure and improve patient workflow and experience. Methods: A secondary analysis was conducted on a single-center cohort of patients undergoing single-photon emission computed tomography (SPECT) and positron emission tomography (PET) studies. Normal MPI was defined by the absence of perfusion abnormalities and other ischemic markers and the presence of normal left ventricular wall motion and left ventricular ejection fraction. A model was derived using a cohort of 18,389 consecutive patients who underwent SPECT and was validated in a separate cohort of patients who underwent SPECT (n = 5,819), 1 internal cohort of patients who underwent PET (n=4,631), and 1 external PET cohort (n = 7,028). Results: Final models were made for men and women and consisted of 9 variables including age, smoking, hypertension, diabetes, dyslipidemia, typical angina, prior percutaneous coronary intervention, prior coronary artery bypass graft, and prior myocardial infarction. Patients with a score ≤1 were stratified as low risk. The model was robust with areas under the curve of 0.684 (95% confidence interval [CI]: 0.674 to 0.694) and 0.681 (95% CI: 0.666 to 0.696) in the derivation cohort, 0.745 (95% CI: 0.728 to 0.762) and 0.701 (95% CI: 0.673 to 0.728) in the SPECT validation cohort, 0.672 (95% CI: 0.649 to 0.696) and 0.686 (95% CI: 0.663 to 0.710) in the internal PET validation cohort, and 0.756 (95% CI: 0.740 to 0.772) and 0.737 (95% CI: 0.716 to 0.757) in the external PET validation cohort in men and women, respectively. Men and women who scored ≤1 had negative likelihood ratios of 0.48 and 0.52, respectively. Conclusions: A novel model, based on easily obtained clinical variables, is proposed to identify patients with low probability of having abnormal MPI results. This point-of-care tool may be used to identify a population that might qualify for stress-first MPI protocols

    Adenovirus and RNA-based COVID-19 vaccines’ perceptions and acceptance among healthcare workers in Saudi Arabia: a national survey

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    Objectives The aim of this study was to compare the perception, confidence, hesitancy and acceptance rate of various COVID-19 vaccine types among healthcare workers (HCWs) in Saudi Arabia, a nation with Middle East respiratory syndrome coronavirus experience. Design National cross-sectional, pilot-validated questionnaire. Setting Online, self-administered questionnaire among HCWs. Participants A total of 2007 HCWs working in the Kingdom of Saudi Arabia participated; 1512 (75.3%) participants completed the survey and were included in the analysis. Intervention Data were collected through an online survey sent to HCWs during 1–15 November 2020. The main outcome measure was HCW acceptance of COVID-19 candidate vaccines. The associated factors of vaccination acceptance were identified through a logistic regression analysis and via measurement of the level of anxiety, using the Generalised Anxiety Disorder 7 scale. Results Among the 1512 HCWs who were included, 62.4% were women, 70.3% were between 21 and 40 years of age, and the majority (62.2%) were from tertiary hospitals. In addition, 59.5% reported knowing about at least one vaccine; 24.4% of the participants were sure about their willingness to receive the ChAdOx1 nCoV-19 vaccine, and 20.9% were willing to receive the RNA BNT162b2 vaccine. However, 18.3% reported that they would refuse to receive the Ad5-vectored vaccine, and 17.9% would refuse the Gam-COVID-Vac vaccine. Factors that influenced the differential readiness of HCWs included their perceptions of the vaccine’s efficiency in preventing the infection (33%), their personal preferences (29%) and the vaccine’s manufacturing country (28.6%). Conclusions Awareness by HCWs of the several COVID-19 candidate vaccines could improve their perceptions and acceptance of vaccination. Reliable sources on vaccine efficiency could improve vaccine uptake, so healthcare authorities should use reliable information to decrease vaccine hesitancy among frontline healthcare providers

    Old World cutaneous leishmaniasis treatment response varies depending on parasite species, geographical location and development of secondary infection

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    Background: In the Kingdom of Saudi Arabia (KSA), Leishmania major and L. tropica are the main causative agents of Old World cutaneous leishmaniasis (CL). The national CL treatment regimen consists of topical 1% clotrimazole/2% fusidic acid cream followed by 1–2 courses of intralesional sodium stibogluconate (SSG); however, treatment efficacy is highly variable and the reasons for this are not well understood. In this study, we present a complete epidemiological map of CL and determined the efficacy of the standard CL treatment regime in several endemic regions of KSA. Results: Overall, three quarters of patients in all CL-endemic areas studied responded satisfactorily to the current treatment regime, with the remaining requiring only an extra course of SSG. The majority of unresponsive cases were infected with L. tropica. Furthermore, the development of secondary infections (SI) around or within the CL lesion significantly favoured the treatment response of L. major patients but had no effect on L. tropica cases. Conclusions: The response of CL patients to a national treatment protocol appears to depend on several factors, including Leishmania parasite species, geographical location and occurrences of SI. Our findings suggest there is a need to implement alternative CL treatment protocols based on these parameters
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