201 research outputs found
A low dose of risperidone resolved Charles Bonnet syndrome after an unsuccessful trial of quetiapine: a case report
No full textSultan H Alamri College of Medicine, King Abdulaziz University, Jeddah, Kingdom of Saudi Arabia Abstract: Charles Bonnet syndrome (CBS) is a diagnosis of exclusion. Typical affected patients have impaired visual acuity, vivid recurring visual hallucinations, and no cognitive impairment. Vision loss is most commonly due to macular degeneration, although many other causes exist. Here, we report a case of an 87-year-old woman with CBS and discuss the diagnosis and treatment. Keywords: Charles Bonnet syndrome, hallucinations, delusion, visual, elderly, geriatri
Advanced Space-Time Coding: Near-Capacity Sphere-Packing, Multi-Functional MIMOs and Cooperative Space-Time Processing
No full textNear-capacity wireless transceivers and cooperative communications in the MIMO era: evolution of standards, waveform design, and future perspectives
No full textClassic Shannon theory suggests that the achievable channel capacity increases logarithmically with the transmit power. By contrast, the MIMO capacity increases linearly with the number of transmit antennas, provided that the number of receive antennas is equal to the number of transmit antennas. With the further proviso that the total transmit power is increased proportionately to the number of transmit antennas, a linear capacity increase is achieved upon increasing the transmit power, which justifies the spectacular success of MIMOs. Hence we may argue that MIMO-aided transceivers and their cooperation-assisted distributed or virtual MIMO counterparts constitute power-efficient solutions. In a nutshell, since the conception of GSM in excess of three orders of magnitude bit-rate improvements were achieved in three decades, which corresponds to about a factor ten for each decade, because GSM had a data rate of 9.6 Kb/s, while HSDPA is capable of communicating at 13.7 Mb/s. However, the possible transmit power reductions remained more limited, even when using the most advanced multistage iterative detectors, since the required received signal power has not been reduced by as much as 30 dB. This plausible observation motivates the further research of advanced cooperation-aided wireless MIMO transceivers, as detailed in this treatis
Near-Capacity Three-Stage Turbo Detection of Irregular Convolutional Coded Joint Sphere-Packing Modulation and Space-Time Coding
No full textKnowledge of the residents at King Abdul-Aziz University Hospital (KAAUH) about palliative care
No full textBackground: Palliative care is a rapidly growing subspecialty that aims at improving the quality of life and relieving suffering associated with life threatening disease. Despite its rapid growth and huge demand, the knowledge of health care professionals on palliative care remains inadequate. Objective: This study aims to determine the knowledge of residents at King Abdul-Aziz University Hospital (KAAUH) on palliative care. Materials and Methods: Through a cross-sectional design, all residents in the hospital were invited to complete a two-part self-administered questionnaire in June 2010. The first part of the questionnaire included variables describing the socio-demographic characteristics and educational background, and the second part developed by palliative care education initiative at Dalhousie University in Canada in 2000 had 25 items on the knowledge of palliative care. Results : Of the 80 residents 65 (81%) responded, the overwhelming majority of whom were Saudis (92.3%) with an equal representation of males and females. The mean age of the participants was 29.1 ± 2.4 years. Less than one-third (29.2%) indicated that they had previous didactic education on palliative care. The percentage of right answers on items reflecting knowledge on palliative care accounted for 29.9% ± 9.9%. No statistically significant difference was found in the level of knowledge among the residents according to their demographics or graduation and training characteristics. Conclusion: Resident physicians enrolled in postgraduate programs have suboptimal knowledge of basic palliative care. Substantial efforts should be made to incorporate a palliative care module into the theoretical and practical training of medical students and resident physicians
An Efficient Approach for Exchanging Exam Contents in E-Learning Institutions
No full textIn some e-learning and blended-learning institutions, such as the Saudi Electronic University (SEU) in Saudi Arabia, prior to the students undertaking exams, the exam questions are distributed to and shared among faculty members. This is done by email which poses a high security risk. Moreover, there is the issue of latency and problems associated with the organization of the exams. Therefore, this paper presents a system to secure the digital content of exam questions and their transmission in e-learning institutions, enabling the control of access to content with suitable management features for security, auditing, and archiving using leading technology solutions for content management and security.</jats:p
Identification of Two Species of the Family Sparidae for eDNA Sequences using a Representative 16SrRNA Reference Library for Omani Fish
No full textIdentification of fish species accurately is required to support efforts for conserving fishery biodiversity assessment and sustainable management. Recently, environmental DNA (eDNA) was suggested for regular monitoring of species for effective management of biodiversity. In Oman, molecular reference library representing fish species from the Omani coastline can support such potential approaches. In this communication, we used a local mtDNA-16SrRNA reference library representing Sparidae fish species from the Omani coastlines to identify two Sparidae eDNA sequences (zotu24 and zotu85, from Muscat and Dhofar, respectively) from Acanthopagrus and Diplodus genera reported by a recent eDNA study from Oman. The two species are found to be Acanthopagrus berda and Diplodus cervinus and their sampling sites matches the locations range of the reference specimens. The results indicate the utility and importance for DNA markers’ reference library representing fish species from the Omani coastline to effectively sustain the marine resources using emerging technologies.
Keywords: Sparidae, eDNA; 16SrRNA; Acanthopagrus berda; Diplodus cervinus; Oman.
 
Involvement of TRPV4 genetic mutations in regulation of intracellular calcium level and bone and cartilage abnormalities
No full text© 2024 Sultan AlamriContinuous remodeling and reshaping of the bones are essential for repairing micro-damaged bones and maintaining calcium balance in the body. The transient receptor potential (TRP) superfamily of genes includes calcium channels that serve as a sensory system for the musculoskeletal system. One such channel is Transient Receptor Potential Vanilloid family member 4 gene (TRPV4), which is a non-selective cation channel capable of allowing calcium ions (Ca2+) to pass through. TRPV4 functions as both a mechanosensory and osmosensory channel, contributing to the development of various musculoskeletal tissues. During the formation of joints, TRPV4 is involved in chondrocyte proliferation and joint shaping. It also plays a crucial role in bone and cartilage development, osmoregulation, pain sensation, and apoptosis.
Considering the crucial functions of TRPV4 in the development of bone and cartilage, it is not surprising that mutations in this mechanosensor channel can result in various skeletal abnormalities. Over 50 mutations in TRPV4 gene have been identified, leading to channelopathies affecting the skeletal system, ranging from dwarfism to prenatal death, skeletal dysplasia, and arthropathies. While the location of the mutation is likely related to the specific phenotype observed, little is currently known about the underlying mechanisms. Therefore, the objective of this project was to investigate the disease mechanisms caused by TRPV4 mutations that disrupt calcium regulation in multiple tissues, particularly chondrocytes. This will be accomplished through experiments involving HEK and chondrocyte cells, as well as mouse models, as TRPV4 mutations result in abnormal bone and cartilage development in human skeletal dysplasias.
Scottish fold cats show a dominantly inherited osteochondrodysplasia involving malformation in the distal forelimbs, distal hindlimbs and tail, and progressive joint destruction. Using genome mapping techniques, our collaborators identified a p.V342F mutation (c.1024G>T) in TRPV4 as the underlying cause of the Scottish fold cat phenotype. Functional analysis in stably transfected HEK293 cells indicated that the TRPV4 V342F variant was weakly expressed on the cell surface in comparison to TRPV4 WT and therefore the maximum response to a synthetic agonist, GSK1016709A, was decreased. A higher basal activity and an increased response to hypotonic conditions were detected in mutant TRPV4 channels
So far, researchers have created TRPV4 knockout (KO) mouse models and transgenic mouse models, where mutated genes are overexpressed alongside a wild-type (WT) background. We have characterised a TRPV4 V620A mouse model, which was generated by ENU mutagenesis, and is the first knock-in TRPV4 mutant mouse.
Our findings revealed significant changes in spine curvature, vertebral angle, tibia and femur length, as well as several trabecular bone parameters in TRPV4 mutant mice compared to WT mice as well as TRPV4 KO mice. The phenotype observed in the TRPV4 V620A mouse is milder compared to the more severe phenotype of the TRPV4 V620I transgenic mouse. Moreover, the TRPV4 V620A mouse exhibits a less pronounced phenotype than the human TRPV4 V620I condition. In contrast to the findings in the transgenic model (V620I mutant), where skeletal malformations were observed in the mutant model compared to WT mice, the TRPV4 V620A mice in this study exhibited no significant alterations when compared to WT mice.
Experiments on the stimulation of the TRPV4 WT, TRPV4 KO, TRPV4V620A/+, and TRPV4V620A/V620A chondrocytes indicated less calcium influx in response to GSK101 stimulation in homozygous mutant chondrocytes compared to WT and heterozygous chondrocytes. Although TRPV4V620A/+, and TRPV4V620A/V620A chondrocytes showed higher constitutive intracellular calcium than WT and KO, after normalization, all mutant and WT chondrocytes and even KO showed a normal peak in response to hypotonicity. However, increased level of [Ca2+]i remained lower in heterozygous and even much lower in homozygous and KO compared to WT, but this level in TRPV4V620A/+ cells reached the same level as WT in sustained phase over the time course. TRPV4 KO and homozygous mutant chondrocytes did not respond to hypotonicity stimulation, while the heterozygous mutant TRPV4 has a reduced response compared to WT. The V620A heterozygous variant showed no significant effect on the response of PAR1 and 2 channels when stimulated with PAR1 and PAR2 agonists.
Experiments to explore the mechanism by which V620I and V620A variants in TRPV4 could disrupt ion channel function in HEK293 cells indicated that TRPV4 WT transfected HEK cells as well as mutant channels responded to agonist GSK101 but non-transfected cells did not respond to the treatment. However, the maximum response to GSK101 was low in both mutant TRPV4 than WT. Same as chondrocytes, in which TRPV4 WT, TRPV4V620A/V620A and TRPV4V620A/+ indicated proper response to GSK101 stimulation, HEK cells transfected with TRPV4 WT, TRPV4 p.620A and TRPV4 p.620I had favorable response towards GSK101 stimulation. HEK cells transfected with TRPV4 p.V620I had a lower maximum response as well as decreased sustained [Ca2+]i level compared to cells expressing WT, subsequent to the adjustment of the leading basal action. This shows that the mutant V620I channels have a low hypotonicity sensitivity than the WT channel. However, cells transfected with TRPV4 p.V620A did not respond to hypotonicity stimulation. The results indicated that PAR1 peak responses in both TRPV4 p.V620A and TRPV4 p.V620A expressing HEK cells. However, the peak response to PAR1 agonist treatment was a little lower in the TRPV4 p.V620A cells compared to the TRPV4 p.V620A expressing cells. The peak responses were typical in TRPV4 WT expressing HEK cells. Same pattern of baseline and peak responses were observed when cells were treated with PAR2 agonist treatment. Therefore, PAR2 stimulates the activation of TRPV4, allowing an influx of calcium.
In conclusion, this research aimed to investigate the role of TRPV4 genetic mutations on the calcium metabolism in different models that might be associated with bone and cartilage abnormalities. Our data on the effect of TRPV4 620A variant on the pathologic presentations of the mouse indicated that this variant was associated with larger thoracolumbar kyphosis and cervicothoracic lordosis, but shorter tibia and femur length, suggest abnormalities during endochondral ossification. Likewise, the larger bone volume fraction and the smaller trabecular number of the trabecular bone, as well as the smaller trabecular separation of the femoral head in the TRPV4V620A/+ and TRPV4V620A/V620A mice compared to WT group, confirmed the hypothesis that this variant has harmful effects on bone development. In addition, TRPV4 620A variant in mouse chondrocytes was associated with an impaired response to the synthetic agonist triggering and hypotonicity stimulation. Putting these observations together, TRPV4 V620A variant is associated with impaired channel function that is probably mirrored in raising pathologic bone and cartilage presentations. On the other hand, the behaviors of HEK cells transfected with TRPV4 620A and TRPV4 620I were not similar to each other. As a consequence, our results on Trpv4 620A variant in mice partly resemble the phenotype of the V620I variant in human Brachyolmia
Nursing Students’ Perception and Attitude towards Objective Structured Clinical Examination in Oman
No full textObjectives: This study aimed to explore undergraduate nursing students’ perception and attitude towards the Objective Structured Clinical Examination (OSCE). Methods: This cross-sectional descriptive study was conducted between April–May 2020 among undergraduate nursing students at the College of Nursing at Sultan Qaboos University, Muscat, Oman. Two self-administered questionnaires were utilised to obtain data on students’ perception and attitude towards OSCE. Students’ feedback on OSCE was collected using open-ended questions about OSCE strengths, weaknesses and recommendations for improvement. Survey responses were based on a five-point ordinal scale, ranging from strongly disagree to strongly agree. Students’ feedback on OSCE was analysed as descriptive data by identifying the common themes and categorising them in groups. Results: A total of 160 students completed the study questionnaires. Most did not find the atmosphere of OSCE to be pleasant (66.3%) and preferred more modes of practical examination (40.6%). Moreover, 64.4% believed the time limitation to be inadequate. The data depict that 33.1% of the examinees deemed the OSCE more stressful than the full practical examination. In addition, a few students confirmed that the OSCE improved their communication skills and confidence in nursing skills. Conclusion: The findings of this study appear alarming in regard to students’ perception regarding the overall process and validity of OSCE as an assessment method. Nursing educators must consider further evaluation and improvement of the OSCE in order to improve students’ acceptance and appreciation of OSCE as an important form of clinical learning and assessment.
Keywords: Clinical Competence; Nursing Education; Baccalaureate; Evaluation; Attitude; Nursing Students; Practical Nursing; Oman
Study the Behavior of Vortex-Antivortex Bundles in He II
No full textAbstract: We present a numerical simulation to compute the evolution of vortex filaments bundle in superfluid helium. We show that the vortex-antivortex bundles with sinusoidally have stable structures and each bundle rotates about its common center. Because of they have circulation in opposing directions, the two vortex bundles move down together parallel to each other. A three dimensional periodic cube is used. Thus, the vortex filament points move through one side of the periodic volume and re-entering on the other side. The two bundles move for long time without reconnection. We found that our results are in agreement with the finding of Koplik and Levine [Phys. Rev. Lett. 71, 137
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