Physiological Intracranial Calcifications in Children: A computed tomography-based study

Objectives: Physiological intracranial calcifications (PICs) are benign in nature and related to aging. We aimed to study the frequency of physiological intracranial calcifications (PICs) in pediatric population using computed tomography (CT). Methods: The brain CT scans of consecutive patients (age range, 0-15 years) who had visited Sultan Qaboos University Hospital from January 2017 to December 2020 were retrospectively assessed for the presence of PICs. The presence of calcifications was identified using 3 mm thick axial images, and coronal and sagittal reformats. Results: A total of 460 patients were examined and the mean age was 6.54 ± 4.94 years. The frequency of PIC in boys and girls was 35.1% and 35.4%, respectively. PICs were most common in choroid plexus with 35.21% (age range 0.4 -15 years; median, 12 years), followed by the pineal gland in 21.08% (age range 0.5 -15 years; median, 12 years) and the habenular nucleus in 13.04% of subjects (2.9 -15 years; median, 12 years). PICs were less common in falx cerebri with 5.86% (age range 2.8-15 years; median, 13 years) and tentorium cerebelli in 3.04% (age range 7-15 years; median, 14 years) of subjects. PICs increased significantly with increasing age (p<0.001). Conclusion: Choroid plexus is the most frequent site of calcification. Choroid plexus and pineal gland calcifications may be present at less than 1 year of age. Recognizing PICs is clinically important for radiologists as they can be mistaken for hemorrhage or pathological entities like neoplasms or metabolic diseases. Keywords: Calcification; Pineal gland; Dura Mater; Brain; Computed Tomograph

Radiologic Assessment of Orbital Dimensions among Omani Subjects: Computed tomography Imaging-based study at a single tertiary center

Objectives: A sound knowledge of the normal orbital dimensions is clinically essential for successful surgical outcomes. Racial, ethnic, and regional variations in the orbital dimensions have been reported. This study aimed to determine the orbital dimensions of Omani subjects who had been referred for computed tomography (CT) images at a tertiary care hospital. Methods: A total of 273 Omani patients referred for a CT scan of the brain were evaluated retrospectively, using electronic medical records database. The orbital dimensions were recorded using both axial and sagittal planes of CT images. Results: The mean orbital index (OI) was found to be 83.25±4.83, and the prevalent orbital type was categorized as mesoseme. The mean orbital index was 83.34±5.05 and 83.16±4.57 in males and females, respectively, with their difference being statistically not significant (p=0.76). A statistically significant association was observed between the right and left orbits regarding horizontal distance (p<0.05) and vertical distance (p<0.01) of orbit and OI (p<0.05). No significant difference between the OI and age groups was observed in males and females. The mean interorbital distance and interzygomatic distance were found to be 19.45±1.52 mm and 95.59±4.08 mm, respectively. These parameters were significantly higher in males (p<0.05). Conclusions: Results of the present study provide reference values of orbital dimensions in Omani subjects. The prevalent orbital type of Omani subjects is mesoseme, which is a hallmark of the white race.  Keywords: Computed Tomography, Ethnicity, Orbit, Oman, Variation, Hypertelorism

Contribution of citizen science to improve knowledge on marine biodiversity in the Gulf Region

Monitoring marine biodiversity is costly and practical solutions have to be implemented to identify species and their preferred habitats, particularly in this era of rapid global change. Citizen science has proven to be effective and with high potential for monitoring efforts, and has been extensively applied to biodiversity. We have used the citizen science approach to engage the general public and stakeholders to contribute improving the current knowledge of sea snake biodiversity in Qatar and the Gulf Region. Logistic regression analysis using demographic data from interview surveys conducted in Qatar has indicated that the people having seen more sea snakes are older than 30 years and are Qatari citizens and/or fishermen from India. Of the ten species of sea snakes listed in the literature to be present in the Gulf Region, most of them have been reported for Qatar, Bahrain, United Arab Emirates and Saudi Arabia. However, the number of species present is often assumed based on their occurrence within the Arabian Gulf rather than on actual captures and appropriate identification. The creation of marine reference biological scientific collections to properly identify the species and make accurate biodiversity inventories is an urgent priority for the countries in the Gulf region. To this end, contributions by stakeholders and the general public for this study have proven to be very useful. However a larger networking with local and international scientists and stakeholders is still needed to adequately survey the country''s current biodiversity, identify research priorities and eventually provide the scientific input needed to assist biodiversity management related to renewable resource management and marine conservation in the Arabian Gulf Region

Tuberculosis suspicion and knowledge among private and public general practitioners: Questionnaire Based Study in Oman

<p>Abstract</p> <p>Background</p> <p>Early detection of smear positive TB cases by smear microscopy requires high level of suspicion of TB among primary care physicians. The objective of this study is to measure TB suspicion and knowledge among private and public sector general practitioners using clinical vignette-based survey and structured questionnaire.</p> <p>Methods</p> <p>Two questionnaires were distributed to both private and public GPs in Muscat Governorate. One questionnaire assessed demographic information of the respondent and had 10 short clinical vignettes of TB and non-TB cases. The second questionnaire had questions on knowledge of TB, its diagnosis, treatment, follow up and contact screening based on Ministry of Health policy. TB suspicion score and TB Knowledge score were computed and analyzed.</p> <p>Results</p> <p>A total of 257 GPs participated in the study of which 154 were private GPs. There was a significant difference between private and public GPs in terms of age, sex, duration of practice and nationality. Among all GPs, 37.7% considered TB as one of the three most likely diagnoses in all 5 TB clinical vignettes. Private GPs had statistically significantly lower TB suspicion and TB knowledge scores than public GPs.</p> <p>Conclusion</p> <p>In Oman, GPs appear to have low suspicion and poor knowledge of TB, particularly private GPs. To strengthen TB control program, there is a need to train GPs on TB identification and adopt a Private Public Mix (PPM) strategy for TB control.</p

Numerical Model‐Software for Predicting Rock Formation Failure‐Time Using Fracture Mechanics

Real‐time integrated drilling is an important practice for the upstream petroleum industry. Traditional pre‐drill models, tend to offset the data gathered from the field since information obtained prior to spudding and drilling of new wells often become obsolete due to the changes in geology and geomechanics of reservoir‐rocks or formations. Estimating the complicated non‐linear failure‐time of a rock formation is a difficult but important task that helps to mitigate the effects of rock failure when drilling and producing wells from the subsurface. In this study, parameters that have the strongest impact on rock failure were used to develop a numerical and computational model for evaluating wellbore instability in terms of collapse, fracture, rock strength and failure‐time. This approach presents drilling and well engineers with a better understanding of the fracture mechanics and rock strength failureprediction procedure required to reduce stability problems by forecasting the rock/formation failuretime. The computational technique built into the software, uses the stress distribution around a rock formation as well as the rock’s responses to induced stress as a means of analyzing the failure time of the rock. The results from simulation show that the applied stress has the most significant influence on the failure‐time of the rock. The software also shows that the failure‐time varied over several orders of magnitude for varying stress‐loads. Thus, this will help drilling engineers avoid wellbore failure by adjusting the stress concentration properly through altering the mud pressure and well orientation with respect to in‐situ stresses. As observed from the simulation results for the failure time analysis, the trend shows that the time dependent strength failure is not just a function of the applied stress. Because, at applied stress of 6000–6050 psi there was time dependent failure whereas, at higher applied stress of 6350–6400 psi there was no time dependent strength failure

A modified empirical criterion for strength of transversely anisotropic rocks with metamorphic origin

A modified empirical criterion is proposed to determine the strength of transversely anisotropic rocks. In this regard, mechanical properties of intact anisotropic slate obtained from three different districts of Iran were taken into consideration. Afterward, triaxial rock strength criterion introduced by Rafiai was modified for transversely anisotropic rocks. The criterion was modified by adding a new parameter α for taking the influence of strength anisotropy into consideration. The results obtained have shown that the parameter α can be considered as the strength reduction parameter due to rock anisotropy. The modified criterion was compared to the modified Hoek–Brown (Saroglou and Tsiambaos) and Ramamurthy criteria for different anisotropic rocks. It was concluded that the criterion proposed in this paper is a more accurate and precise criterion in predicting the strength of anisotropic rocks

Herd immunity against severe acute respiratory syndrome coronavirus 2 infection in 10 communities, qatar

We investigated what proportion of the population acquired severe acute respiratory syndrome coronavirus 2 (SARSCoV- 2) infection and whether the herd immunity threshold has been reached in 10 communities in Qatar. The study included 4,970 participants during June 21-September 9, 2020. Antibodies against SARS-CoV-2 were detected by using an electrochemiluminescence immunoassay. Seropositivity ranged from 54.9% (95% CI 50.2%-59.4%) to 83.8% (95% CI 79.1%-87.7%) across communities and showed a pooled mean of 66.1% (95% CI 61.5%-70.6%). A range of other epidemiologic measures indicated that active infection is rare, with limited if any sustainable infection transmission for clusters to occur. Only 5 infections were ever severe and 1 was critical in these young communities; infection severity rate of 0.2% (95% CI 0.1%-0.4%). Specifi c communities in Qatar have or nearly reached herd immunity for SARS-CoV-2 infection: 65%-70% of the population has been infected.This study was supported by the Hamad Medical Corporation, Ministry of Public Health, and the Biomedical Research Program and the Biostatistics, Epidemiology, and Biomathematics Research Core, both atScopu