What do non-ophthalmic health professionals know about retinoblastoma: a survey in Saudi Arabia

Background: The aim of the study is to estimate the level of knowledge about retinoblastoma (Rb) and its determinants among non-ophthalmic health professionals of Qassim region of Saudi Arabia.Methods: This cross-sectional survey was held in 2016 in primary health centres (PHC) and general hospitals in the study area. In addition to demography like age, gender, education, place of work, participants replied to five questions related to Rb with close-ended questions to respond. They were matched to the expert group's answers to estimate the level of knowledge.Results: One hundred and fifty-two non-ophthalmic doctors participated in the survey. The excellent grade of knowledge of Rb was in 66 [43.3% (95% confidence interval 35.5-51.3)] of participants. Very poor level of knowledge was noted in 13 [8.6% (95% CI 4.1-13.0)] participants. Male gender (P = 0.02) and physician category (P = 0.02) were significantly associated with the excellent grade of Rb related knowledge. The participant’s response by type of questions varied significantly (P<0.001).Conclusions: More than half of the non-ophthalmic health professionals had less than desired knowledge about Rb. Health education about Rb to health professionals could be gender sensitive and based on the type of profession. Increasing the awareness about retinoblastoma among non-ophthalmic health professional is important

MAT-712: MICROSTRUCTURAL INVESTIGATIONS ON THE SELF-HEALING ABILITY OF ENGINEERED CEMENTITIOUS COMPOSITES INCORPORATING DIFFERENT MINERAL ADMIXTURES

The present study investigates the impacts that self-healing has on the microstructure characteristics of microcracked Engineered Cementitious Composites (ECC). These have two contrasting maturity levels and, furthermore, they involve three varying mineral admixtures that have very different chemical constituents. The impact of self-healing on the transport characteristics was examined by employing rapid chloride permeability tests (RCPT). The findings indicated that, if the appropriate mineral admixture type and conditioning were chosen, it would be possible to enhance the majority of the chloride ion penetrability levels following a 30-day period of water curing. As a result, the majority of the findings were in range of the low penetrability level over the 30 days, as set by ASTM C1202. The microstructural indications corroborated the findings from the experiments and provided weight to the notion that the causal factor of the healing was the appearance of calcium carbonate and C-S-H. These served to fill the crack owing to the hydration of the cementitious particles. In summary, the results indicate that the degree of self-healing is subject to variance in accordance with the contrasting chemical compositions that dominate within a certain infrastructure type over the course of its service life

Impact resistance of deflection-hardening fiber reinforced concretes with different mixture parameters

YesThe impact behavior of deflection-hardening High Performance Fiber Reinforced Cementitious Concretes (HPFRCs) was evaluated herein. During the preparation of HPFRCs, fiber type and amount, fly ash to Portland cement ratio and aggregate to binder ratio were taken into consideration. HPFRC beams were tested for impact resistance using free-fall drop-weight test. Acceleration, displacement and impact load vs. time graphs were constructed and their relationship to the proposed mixture parameters were evaluated. The paper also aims to present and verify a nonlinear finite element analysis, employing the incremental nonlinear dynamic analysis, concrete damage plasticity model and contact surface between the dropped hammer and test specimen available in ABAQUS. The proposed modelling provides extensive and accurate data on structural behavior, including acceleration, displacement profiles and residual displacement results. Experimental results which are further confirmed by numerical studies show that impact resistance of HPFRC mixtures can be significantly improved by a proper mixture proportioning. In the presence of high amounts of coarse aggregates, fly ash and increased volume of hybrid fibers, impact resistance of fiberless reference specimens can be modified in a way to exhibit relatively smaller displacement results after impact loading without risking the basic mechanical properties and deflection-hardening response with multiple cracking

Molecular characterization of Leishmania species from stray dogs and human patients in Saudi Arabia

Leishmania major and Leishmania tropica cause cutaneous leishmaniasis in humans and dogs in several parts of the world, with a large number of cases recorded in the Middle East. However, when they occur in sympatry, the role of each species of Leishmania in the epidemiology of cutaneous leishmaniasis (CL) is not clear. To assess the frequency and to identify the species of Leishmania that infect humans and stray dogs in Riyadh and Al-Qaseem (Saudi Arabia), 311 stray dogs and 27 human patients who were suspected for Leishmania infection were examined for CL by a nested polymerase chain reaction (nPCR). Seven (25.9%) out of 27 human patients scored positive for Leishmania spp. (i.e., L. major in five patients from Riyadh and L. tropica in two patients from Al-Qaseem). Out of 311 dogs, five (1.6%) were infected by L. tropica. Data herein presented demonstrate the occurrence of L. tropica in dogs and humans in Saudi Arabia, as well as the occurrence of L. major in humans

Ticks and associated pathogens in camels (Camelus dromedarius) from Riyadh Province, Saudi Arabia

Background: Camel production in Saudi Arabia is severely affected by various diseases and by inadequate veterinary services. Ticks and tick-borne pathogens (TBPs) affect the health and wellbeing of camels consequently diminishing their productivity and performances. In addition, camels may act as hosts for TBPs (e.g. Anaplasma phagocytophilum) causing diseases in humans. The current study aimed to determine the prevalence of ixodid ticks and molecularly investigate the associated pathogens in camels from Saudi Arabia. Methods: Blood and tick samples were collected from camels (n = 170) in Riyad Province of Saudi Arabia. Ticks were morphologically identified, and blood of camels were molecularly screened for apicomplexan (i.e. Babesia spp., Theileria spp., Hepatozoon spp.) and rickettsial parasites (i.e. Ehrlichia spp. and Anaplasma spp.). Results: Of the 170 camels examined, 116 (68.2%; 95% CI: 60.9-75.1%) were infested by ticks with a mean intensity of 2.53 (95% CI: 2.4-2.6). In total of 296 ticks collected, Hyalomma dromedarii was the most prevalent (76.4%), followed by Hyalomma impeltatum (23.3%) and Hyalomma excavatum (0.3%). Of the tested animals, 13 (7.6%; 95% CI: 4.3-12.8%) scored positive to at least one TBP, with Anaplasma platys (5.3%; 95% CI: 2.7-9.9%) being the most prevalent species, followed by Anaplasma phagocytophilum, Anaplasma sp., Ehrlichia canis and Hepatozoon canis (0.6% each; 95% CI: 0.04-3.4%). None of the camels were found to be co-infected with more than one pathogen. All samples tested negative for Babesia spp. and Theileria spp. Conclusions: The present study reveals the occurrence of different tick species and TBPs in camels from Saudi Arabia. Importantly, these camels may carry A. phagocytophilum and A. platys, representing a potential risk to humans.[Figure not available: see fulltext]

MOLECULAR EPIDEMIOLOGICAL STUDIES ON TRYPANOSOMA EVANSI TYPE A AND TYPE B IN CAMELS (CAMELUS DROMEDARIES) FROM FIVE DIFFERENT REGIONS OF SAUDI ARABIA USING THE ITS1 RDNA AND ROTAT 1.2 VSG GENE

Trypanosoma evansi is the most widespread of the pathogenic salivarian trypanosomes and cause a serious disease called (surra) that is affect the domestic animals such camels and horses in Tropical and subtropical countries and often leads to reduced productivity and economic losses. Therefore, the objectives of the present study were to determine the prevalence rates of trypanosomiasis using polymerase chain reaction (PCR) among camels from five different regions of Saudi Arabia and to sequence and characterized the T. evansi from these animals. In the current study, 832 camel blood samples collected from five different regions of Saudi Arabia for detecting T. evansi. A generic ITS1-PCR and RoTat 1.2 VSG gene were applied in this study to analyze camels’ blood samples. Molecular analysis was performed using ITS1-PCR which showed that the highest prevalence of trypanosomes was observed in Al-Qaseem province (50.1%) followed Riyadh province (49%), whereas in Hail and the Northern Borders, there were fewer infections with trypanosomes (28.4% &17.6%), respectively. PCR amplification was carried out targeting RoTat 1.2 VSG gene on TS1-positive samples and some of them were negative for RoTat1.2. The test negative in RoTat 1.2 PCR but ITS1 PCR positive could suggest T. evansi type B. Presence of T. evansi type B is interest to the international community, as this has a message to redesign the existing molecular and serological diagnostic markers. However, to our knowledge this the first study demonstrating T. evansi type B out of Africa. Keywords: Trypanosoma evansi, Camels, ITS1 rDNA , RoTat 1.2, PCR, Saudi Arabia

The Effect of Applied Stress on Environment-Induced Cracking of Aluminum Alloy 5052-H3 in 0.5 M NaCl Solution

The environment-induced cracking (EIC) of aluminum alloy 5052-H3 was investigated as a function of applied stress and orientation (Longitudinal rolling direction—Transverse: LT and Transverse—Longitudinal rolling direction: TL) in 0.5 M sodium chloride solution (NaCl) using a constant load method. The applied stress dependence of the three parameters (time to failure; tf, steady-state elongation rate, Iss, and transition time at which a linear increase in elongation starts to deviate, tss) obtained from the corrosion elongation curve showed that these relationships were divided into three regions, the stress-dominated region, the EIC- dominated region, and the corrosion-dominated region. Aluminum alloy 5052-H3 with both orientations showed the same EIC behavior. The value of tss/tf in the EIC-dominated region was almost constant with 0.57±0.02 independent of applied stress and orientation. The fracture mode was transgranular for 5052-H3 with both orientations in the EIC-dominated region. The relationships between log Iss and log tf for 5052-H3 in the EIC-dominated region became a good straight line with a slope of −2 independent of orientation

Quality of anticoagulation control among patients with atrial fibrillation: An experience of a tertiary care center in Saudi Arabia

Background: Atrial fibrillation (AF) is the most common chronic rhythm disorder. Patients with AF are at an increased risk of ischemic stroke. Therefore, optimal anticoagulation is essential to reduce the risk of stroke. The aim of this study was to assess the level of anticoagulation control achieved in patients with nonvalvular AF receiving medical care in a tertiary care hospital. Methods: This was a retrospective cohort study in ambulatory care clinics at tertiary care hospital in Saudi Arabia. We included 110 nonvalvular AF patients treated with warfarin for at least 3 months at King Abdulaziz Medical City, Riyadh, Saudi Arabia, between May 1, 2012, and July 31, 2012. Thereafter, international normalized ratio results were collected for 1 year. Anticoagulation control was assessed by calculating time within therapeutic range (TTR) as per the Rosendaal method. Results: The mean age was 64.9 ± 16.5 years; 60.9% were female. The mean TTR was 59%. Almost one third of the patients (32.7%) had poor anticoagulation control; TTR of <50%. Poor anticoagulation control was significantly associated with higher CHADS2 (congestive heart failure, hypertension, age, diabetes, stroke) score (p = 0.043). TTR was not significantly different between men and women. Similarly, TTR was not associated with age or duration of anticoagulation. There was no adequate information to assess the effect of other factors such as diet, compliance, and level of education on anticoagulation. Thirty-one patients (28.2%) had a history of prior stroke. The overall quality of anticoagulation was not significantly different between patients with and without stroke, (TTR was 56.3% and 60.1%, respectively; p = 0.46). Conclusion: Quality of anticoagulation in patients with AF receiving medical care in a tertiary care hospital was suboptimal, with nearly 40% of the time spent outside the therapeutic range. Methods to improve anticoagulation control among patients with AF should be implemented

Aviation fuel demand modelling in OECD and developing countries: impacts of fuel efficiency

On the quest for reducing the fuel consumption per passenger per flight for economical and environmental reasons, commercial aircraft manufacturers are implementing new strategies for optimising aircraft performance by using new lighter and stronger materials and enhancing engines' efficiencies in terms of fuel consumption and maintenance requirements. With the rising and falling of economies, whether in the Organization for Economic Cooperation and Development (OECD) countries or other developing countries, the aviation industry has been affected by multiple factors such as passenger traffic, freight traffic, airport capacities and oil prices. Aircraft manufacturers have worked on improving the engine efficiency of their newly built airplanes (e.g. Airbus's A-380 and Boeing's B-787), and many airports in the world have increased the number of their runways to face the increasing demand for air traffic in the world. Aviation efficiency can also be achieved through better load management, which in return enables airliners to cope with higher oil prices or rising costs. Aviation fuel demand is modelled in OECD North America, Europe and Pacific regions and some selected developing countries. Price elasticities of fuel demand in all regions are low, while income elasticities are high. The elasticity of aviation fuel demand on passenger kilometre performed (PKP) is considerably low. One per cent increase in PKP leads to less than half a per cent increase in aviation fuel demand, confirming an ongoing fuel efficiency in aviation industry. Copyright 2009 The Authors. Journal compilation 2009 Organization of the Petroleum Exporting Countries.