Optimal irrigation scheduling under water quantity and quality constraints accounting for the stochastic character of regional weather patterns

In arid countries both water scarcity and salinity represent the key factors which drastically limit crop yield in irrigated agriculture. In addition, relatively poor management practices with pretty low water productivity (WP) seriously aggravate the situation. In order to get “more crop per drop', i.e., to substantially improve water use efficiency, this thesis proposes the novel strategy NEMO (Nested Experimental, Modeling, and Optimization Strategy) for reliably evaluating an optimal irrigation schedule. The proposed methodology relies upon a close interaction between in-depth field investigations and physically based process modeling. It is tailored specifically to fit the requirements in resource-restricted regions. Comprehensive field experiments, on site measurements as well as various laboratory analyses provide a representative database for characterizing the relevant environmental parameters as e.g. the soil properties at the considered location and the prevailing climate. A substantial part of the data obtained from the field experiments provided the input for the internationally recognized SVAT software DAISY1 or APSIM2, both physically based irrigation models which have already been successfully applied in arid regions. APSIM - which is used in the advanced parts of the study - includes not only a process based model for soil moisture transport but also a plant physiological model which describes the plant behavior under specific irrigation scenarios for a selected crop throughout a growing season. The adaption of the irrigation model to local conditions and its preliminary parameterization firstly follows available guidelines and data for areas with similar climate and soil conditions. Reference data and deterministic weather data served to build up DAISY’s basic model files. DAISY is then used within the framework of the custom made and problem oriented optimization software GET-OPTIS for evaluating the corresponding optimal irrigation schedule for a first preliminary series of experiments (IrrEx1). A second series of field experiments (IrrEx2) was accompanied by transient soil moisture measurements, which served for evaluating the soil hydraulic parameters, while the obtained yield was used for calibrating the plant physiological model of APSIM. Taking still into account the stochastic nature of weather phenomena, a stochastic optimization with GET-OPTIS was then applied not only for the traditional full irrigation but also for the most important deficit irrigation and the irrigation with saline water. The obtained optimal irrigation schedules are subsequently used for a final series of rigorous irrigation experiments (IrrEx3) which specifically focused on: (1) full irrigation for high yields with most economic water application, (2) deficit irrigation aiming at a maximum yield with only a limited amount of irrigation water, and (3) full irrigation with saline irrigation water for maximum yield. At the harvesting time, the observed crop yield and the water productivity were compared - together with other plant characteristics - with the corresponding calculated values. The agreement between calculated and measured crop data was excellent. All the field experiments have been performed following a parallel use of the common traditional FAO class A-Pan method and the novel NEMO technology. Based on the outcome of the field experiments, the NEMO applications demonstrated a striking superiority throughout all scenarios as compared to the FAO method as regards economic efficiency and sustainable use of irrigation water in both aspects water quantity and salt accumulation. Contrary to common practice, the optimal NEMO irrigation schedule - which relies on stochastic weather data - has an extended validity. Together with the use of physical data and adequate process models, the developed methodology features a highly promising potential for generalizing the experimental findings for other, environmentally similar, regions. NEMO thus opens wide possibilities for a cost effective and sustainable long-term application to other arid or semi-arid areas

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

First Reported Case of Arrhythmogenic Right Ventricular Cardiomyopathy in Oman

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a rare genetic disorder characterized by fatty degeneration of the right ventricular myocardium with variable involvement of the left ventricle. The condition is associated with exercise-mediated ventricular tachycardia and is one of the recognized causes of sudden cardiac death in the young and in athletes. Here, we report the first confirmed case of ARVC in Oman and present its electrocardiographic, echocardiographic features, and radiological findings on gated, contrast-enhanced cardiac computed tomography. Our patient was a 22-year-old male who had presented to our hospital for evaluation and investigation of syncope and symptomatic palpitations

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

Utility of Magnetic Resonance Imaging T2* in Diagnosing and Monitoring Severe Cardiac and Hepatic Siderosis

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Vascular Anomalies in Children Misdiagnosed with Asthma : Case series

In most asthmatic children, inhaled steroids can relieve and control the symptoms of asthma. Persistent wheezing and respiratory symptoms in young children despite appropriate treatment may indicate other diagnostic considerations. Delays in this diagnosis can result in unnecessary investigations, inappropriate treatment and further complications. We report three patients who presented to Sultan Qaboos University Hospital, Muscat, Oman, in the period between September 2010 and May 2012 with persistent wheezing due to compression of the trachea caused by vascular anomalies. All patients had double aortic arches putting pressure on the trachea, leading to respiratory manifestations and feeding problems. Following surgery, all cases showed improvement and no longer required medication. Without clinical suspicion and appropriate imaging, congenital vascular anomalies may remain undetected for years. Infants and children with chronic wheezing should be evaluated for vascular anomalies as soon as possible. General practitioners should refer all such patients to a tertiary-level hospital for further investigations and management

Prevalence and Associated Factors of Diabetes Mellitus Type 2 Among Tuberculosis Patients in Muscat, Oman, 2017–2020

Objectives: Diabetes mellitus (DM) and tuberculosis (TB) are global public health concerns and leading causes of mortality and morbidity worldwide. Coinfection is known to complicate TB control and outcomes. However, there is no national study regarding the prevalence of DM among TB patients in Oman. The objective of the current study was to assess the prevalence of DM and its associated factors among TB patients in Muscat, Oman. Methods: We conducted an analytical cross-sectional study using secondary data from the electronic system of the Ministry of Health (Al-Shifa 3+). It includes all adult TB patients in Muscat, from 2017–2020. Sociodemographic data, clinical characteristics, and comorbidities of TB patients were collected. SPSS with 95% CI and p-value ≤ 0.05 was used for statistical analysis. Results: Of 426 TB cases, the prevalence of DM was 27.0%. The associated factors of DM were age group 40–54 years (odds ratio (OR) = 9.08, 95% CI: 4.16–19.84) and ≥ 55 years (OR = 11.35, 95% CI: 5.19–24.82), male (OR = 2.35, 95% CI: 1.45–3.81), being married (OR = 13.18, 95% CI: 4.72–36.84), being employed (OR = 2.30, 95% CI: 1.19–4.47), and Bangladeshi (OR = 7.08, 95% CI: 2.50–20.12) or Indian (OR = 6.14, 95% CI: 2.40–15.70) nationality. The absence of Bacillus Calmette–Guérin scar (OR = 2.06, 95% CI: 1.19–3.56), death (OR = 7.08, 95% CI: 1.26–7.82), and cured after TB treatment (OR = 3.02, 95% CI 1.71–5.31) showed significant association. Also, smoking (OR = 2.93, 95% CI: 1.81–4.76), drinking alcohol (OR = 1.79, 95% CI: 1.10–2.91), hypertension (OR = 10.45, 95% CI: 5.29–20.64), heart disease (OR = 8.50, 95% CI: 1.69–42.77), and renal disease (OR = 4.84, 95% CI: 1.71–13.64) contributed to the study’s comorbidities. Old age (adjusted OR = 2.30, 95% CI: 1.72–3.06) and hypertension (adjusted OR = 5.21, 95% CI: 2.28–11.87) were found to be predictors of DM among TB patients. Conclusions: The prevalence of DM among TB patients in Muscat is high. Integrated systematic bidirectional TB-DM screening is needed. Furthermore, special attention is required for associated factors when managing these comorbidities

A service-based system for malnutrition prevention and self-management

Malnutrition is considered one of the root causes for the occurrence of other diseases. It is particularly common in the ageing population, where it requires more efficient handling and management to enable longer home independent living. However, to achieve this, a number of related challenges need to be overcome, especially those related to management of health and disease let alone other social and logistical barriers. This paper presents the design of a distributed system that enables homecare management in the context of self-feeding and malnutrition prevention through balanced nutritional intake. The design employs a service-based system that incorporates a number of services including monitoring of activities, nutritional reasoning for assessing feeding habits, diet recommendation for food planning, and marketplace invocation for automating food shopping to meet dietary requirements. The solution is deployed in a small pilot in 12 elder adult houses that, in early results, demonstrates its holistic user-centred scalable approach for malnutrition self-management

Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world

Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic. Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality. Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States. Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis. Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection

Role of Magnetic Resonance Cholangiopancreatography in the Evaluation of Biliary Disease

Magnetic resonace cholangiopancreatography (MRCP) was introduced in 1991, as a non-invasive method of imaging the biliary tree. Although endoscopic cholongiopancreatography (ERCP) has been the mainstay for diagnosing and treating pancreatico-biliary disease, complications such as pancreatitis, cholangitis, haemorrhage and duodenal perforation have limited its use as a routine diagnostic test. Although ERCP is still the standard of reference for imaging the pancreatico-biliary system, MRCP is the examination of choice in a setting where ERCP is difficult or impossible. It is useful in cases with severe biliary obstruction to evaluate the ducts proximal to the obstruction. MRCP has specific advantages over ERCP as it is non-invasive, cheaper, uses no radiation, requires no anaesthesia and is less operator dependent. When combined with conventional T1- and T2-weighted sequences, it allows detection of extraductal disease. The technology is still evolving to make the MRCP examination faster, sharper and with higher spatial resolution