Asthma Control Impact on the Quality of Life and Parent's Educational Degree Effect on Asthma Control among Pediatric Patients in Saudi Arabia, Riyadh City

Asthma is Common, Chronic, and Serious respiratory disease which affect all age groups, especially children, Asthma according to GINA 2016 now days affecting 1-18 % of the population of many different countries around the world. (1) in 2013 a study has been conducted in Saudi Arabia, findings showed that those diagnosed with asthma in KSA do not have good control over their condition; incidence of asthma attacks and referral to hospitals for asthma management were considerably high. (2) The objective of this study is to be able to describe in detail the level of Asthma control among participant and to find the correlation between the control level of the disease and the impact on the pediatric asthmatic patients' quality of life, Also, as a secondary objective we were looking for any correlations with the control of asthma with the parents' education degree. This study was carried out from 5 October 2017 until 3 November 2017, cross-sectional study with a questionnaire which was disturbed. A total 559 child who was diagnosed by asthma were included in the study, For the asthma control test (see figure 1), we found the majority had uncontrolled asthma (45.1%), Most of the children scored 'Never' in Quality of Life Questionnaire when asked in nearly all twelve aspects of the child life. Our results suggest that uncontrolled asthma associated with low quality of life, we did not find any association between asthma control level and Educational degree of the parents. Keywords: Asthma, Asthma control, prevalence of asthma, Saudi arabia, chronic airway diseas

Highly Selective Au/ZnO via Colloidal Deposition for CO2 Hydrogenation to Methanol: Evidence of AuZn Role

Gold, Au nanoparticles were deposited on ZnO, Al2O3, and Ga2O3 via colloidal method in order to investigate the role of support for CO2 hydrogenation to methanol. Au/ZnO was also produced using impregnation method to investigate the effect of colloidal method to improve methanol selectivity. Au/ZnO produced via sol immobilization showed high selectivity towards methanol meanwhile impregnation method produced Au/ZnO catalyst with high selectivity towards CO. The CO2 conversion was also influenced by the amount of Au weight loading. Au nanoparticles with average diameter of 3.5 nm exhibited 4% of CO2 conversion with 72% of methanol selectivity at 250 °C and 20 bar. The formation of AuZn alloy was identified as active sites for selective CO2 hydrogenation to methanol. Segregation of Zn from ZnO to form AuZn alloy increased the number of surface oxygen vacancy for CO2 adsorption to form formate intermediates. The formate was stabilized on AuZn alloy for further hydrogenation to form methanol.  The use of Al2O3 and Ga2O3 inhibited the formation of Au alloy, and therefore reduced methanol production. Au/Al2O3 showed 77% selectivity to methane, meanwhile Au/Ga2O3 produced 100% selectivity towards CO. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

The effect of corporate governance mechanisms on earnings management practices in Saudi listed companies

The main objective of this thesis is to examine the impact of corporate governance mechanisms on earnings management practices in Saudi Arabia. To achieve this aim, the study first analyses the relationship between the level of compliance with the Saudi Corporate Governance Code (SCGC) and earnings management practices by employing a self-constructed corporate governance index (i.e., the compliance-index model), derived mainly from the 2017 Saudi Corporate Governance Code. Second, the study examines the association between a number of individual corporate governance mechanisms (i.e., the equilibrium-variable model) and earnings management practices in Saudi listed firms. Third, it examines the influence of family ownership on the association between corporate governance mechanisms (measured by a comprehensive governance index) and earnings management practices in Saudi listed firms. Through use of a sample of 112 Saudi listed firms between 2006 and 2017 (i.e., 994 firm-year observations) together with insights from agency theory, the compliance index model produces results showing a statistically significant and negative association between the Saudi Corporate Governance Index (SCGI) and the level of earnings management practices. However, this result does not hold for firms with high family ownership, since the results reveal that the effectiveness of corporate governance (measured by the SCGI) in constraining earnings management is reduced in Saudi firms with high family ownership. In a series of sensitivity analyses, this evidence is robust to (i) alternative earnings management models, (ii) endogeneity, and (iii) alternative proxy for family control. Regarding the equilibrium-variable model, the results indicate that Saudi firms are likely to have lower levels of earnings management practices if they have a high percentage of strictly independent directors on the boards, a larger board size, and audit committees that meet more often. Additionally, the results show that Saudi firms with higher government ownership, institutional ownership and family ownership have lower levels of earnings management practices. In contrast, the current study did not find any evidence that the strict independence of audit committee index, percentage of directors with multiple directorships, percentage of family directors on the board and percentage of blockholders ownership have any significant relationship with the extent of earnings management practices in the Saudi firms. Also, the study found that non-strict board/audit independence is not effective in reducing earnings management practices in Saudi firms. These results are moderately robust to (i) alternative earnings management models, (ii) endogeneity, and (iii) alternative proxies for strict board independence. Finally, the findings of this study indicate the effectiveness of the governance provisions provided in the 2017 Saudi Corporate Governance Code in improving governance practices in the Saudi context

High temperature stress on cereal photosynthesis: a re-evaluation

Under natural conditions, crop plants are likely to experience high leaf temperatures that reduce plant growth, reproduction, and photosynthesis, which impact dramatically on crop yield. Some wild plants such as Agave can withstand prolonged periods of Tleaf in excess of 55⁰C but the mechanisms of thermotolerance are unclear at present. To establish whether there is sufficient genetic diversity to be exploited for developing heat tolerant crops, a comparative study was conducted to assess the effects of high leaf temperatures (Tleaf) on two barley lines (C3, Optic and Local) and two maize lines (C4, Sundance and Katumani) that are routinely grown in temperate and sub-tropical regions, respectively, in addition to the obligate C3 plant Yucca filimentosa that is endemic to hot arid habitats. Gas exchange measurements show light saturated CO2 assimilation rates (Asat) and the carboxylation coefficient (the efficiency of CO2 fixation, CO2) were irreversibly suppressed to approximately 20% of their pre-treatment levels immediately after raising Tleaf to 38.0 (± 0.2 ⁰C) for 3 hours in all lines regardless of their origins (temperate or sub- tropical), and this inhibition was not attributed to stomatal closure. In contrast, Y. filimentosa showed a close correspondence between Asat and stomatal conductance (gs) in response to leaf temperatures between 36° to 40°C with a marked suppression immediately after heat stress and rapid full recovery following one hour of release from stress. Above 40°C however, stomata respond differently by opening and increase gs. This pattern suggested the response of stomata in Y. filimentosa is regulated by temperature. There is a general consensus that the primary site of thermal injury to CO2 assimilation is RuBisCO Activase but this is contentious. In this study the effects of high leaf temperatures (Tleaf) on photosynthetic efficiency of barley were re-investigated. Parallel measurements using a range of techniques confirmed that the suppression of Asat was not attributable to Maximum Quantum Efficiency of PSII (ФPSII), or changes in the light harvesting capacity (leaf absorbance, Chla fluorescence excitation spectra), or in vitro electron transport rates. Metabolomics profiling of heat stressed and control leaves showed that carbon flow between Ribose 5-phosphate (Ri5P) and 3-phosphoglycerate (3-PGA) was severely impaired by heat stress, consistent with the assertion that Asat was suppressed by inhibition of RuBisCO activity. Surprisingly, enzyme-linked assays on RuBisCO prepared from leaves exposed to 38.0° (± 0.2°C) for 3 hours showed unequivocally that RuBisCO activity was not affected suggesting the substrates for RuBisCO (CO2 and/or RuBP), rather than RuBisCO activity itself, accounted for the decrease in carbon flow from Ri5P to 3-PGA. These studies also showed that the standard procedures for isolating RuBisCO from cereal leaves lead to a partial re-activation of RuBisCO resulting in false conclusions on the in vivo activation state of the enzyme. The implications of these results are discussed. In intact barley leaves, the suppression in Asat was not reversed by increasing external CO2 (Ca) to 1000 μmol CO2. mol-1 air suggesting chloroplast CO2 levels were not limiting. In vitro assays demonstrated the activities of Ri5P isomerase and phosphoribulose kinase (PRK) were not affected by these heat stress treatments. In contrast, measurements on leaf ATP levels and in vivo electron transport rate (ETR) showed a parallel and dramatic decline (>75%). Post-illumination chlorophyll fluorescence relaxation (light-to-dark transition) was used to assess the magnitude of the proton motive force (pmf) across the thylakoid membrane of control and heat stressed leaves. Heat stress increased the relaxation half time (t½) from 45 to 180 seconds suggesting a decrease in proton conductance through the ATP synthase, and thus a decrease in leaf ATP levels1. Taken together these results suggest high leaf temperatures lead to a decrease in chloroplast ATP levels and this suppresses the synthesis of Ribulose 1,5-Bisphosphate by the C3 Cycle; carbon flow through RuBisCO is impaired and thus whole leaf photosynthesis rates decline severely

Optimisation of a propagation model for last mile connectivity with low altitude platforms using machine learning

This thesis was submitted for the award of Doctor of Philosophy and was awarded by Brunel University LondonOur related research review on propagation models reveals six factors that are significant in last mile connectivity via LAP: path loss, elevation angle, LAP altitude, coverage area, power consumption, operation frequency, interference, and antenna type. These factors can help with monitoring system performance, network planning, coverage footprint, receivers’ line-of-sight, quality of service requirements, and data rates which may all vary in response to geomorphology characteristics. Several competing propagation models have been proposed over the years but whilst they collectively raise many shortcomings such as limited altitude up to few tens of meters, lack of cover across different environments, low perdition accuracy they also exhibit several advantages. Four propagation models, which are representatives of their types, have been selected since they exhibit advantages in relation to high altitude, wide coverage range, adaption across different terrains. In addition, all four have been extensively deployed in the past and as a result their correction factors have evolved over the years to yield extremely accurate results which makes the development and evaluation aspects of this research very precise. The four models are: ITU-R P.529-3, Okumura, Hata-Davidson, and ATG. The aim of this doctoral research is to design a new propagation model for last-mile connectivity using LAPs technology as an alternative to aerial base station that includes all six factors but does not exhibit any of the shortcomings of existing models. The new propagation model evolves from existing models using machine learning. The four models are first adapted to include the elevation angle alongside the multiple-input multiple-output diversity gain, our first novelty in propagation modelling. The four adapted models are then used as input in a Neural Network framework and their parameters are clustered in a Self-Organizing-Map using a minimax technique. The framework evolves an optimal propagation model that represents the main research contribution of this research. The optimal propagation model is deployed in two proof-of-concept applications, a wireless sensor network, and a cellular structure. The performance of the optimal model is evaluated and then validated against that of the four adapted models first in relation to predictions reported in the literature and then in the context of the two proof-of-concept applications. The predictions of the optimised model are significantly improved in comparison to those of the four adapted propagation models. Each of the two proof-of-concept applications also represent a research novelty.The Royal Saudi Embassy and the Saudi Cultural Bureau in London, and Taif University in the Kingdom of Saudi Arabia

Behavioral Problems Associated with Attention Deficit/Hyperactivity Disorder Among Students as Perceived by Elementary School Teachers in Riyadh

This study was aimed at measuring the differences of elementary school teachers’ perceptions of behavioral problems that appear in pupils with attention deficit hyperactivity disorder (ADHD). The study focused on measuring any statistically significance differences of some variables and their relationship to the extent of realization of teachers. These variables included gender, level of education, years of experience, teacher's current position, previous experience in teaching pupils with ADHD, and training. This research applied the descriptive approach, using a questionnaire. The study sample included 304 male elementary school teachers and 301 female elementary school teachers. The study found several results; no statistically significant differences at the 0.05 level or less regarding teachers’ perceptions of behavioral problems in pupils with ADHD and level of education. The study also showed statistically significant differences between the perceptions of teachers and gender, years of experience, teacher's current position, previous experience in teaching pupils with ADHD, and training

Design of a Model of Forearm Bone Fractures for Educational Purposes

This work explore new approach to demonstrate possible forearm fractures in humans as an educating means for student radiographers. The Design of abnormal bones are not normally available as phantoms, the manufacturer usually produce normal human musculoskeletal models for educational purpose. Hence fractures and abnormalities are usually first time observed by the students in clinical practice at the hospital, the author believe that this work can positively improve the clinical skill laboratories sessions at an earlier stage prior to the hospital training. With the help of such phantom, it can be considered as foundation practical sessions added to radiographic techniques, clinical practice and pathology courses to students radiographers and technologist. Moreover, a model was developed with high quality and low cost produced by local materials for medical education purposes. The present result indicated that the use of models for education and training purposes where interactive training tools will improve the learning experience, and reduces the time on task for students and the material costs as well. Keywords: Forearm, Fractures, Educational Purpose

Sleep disorders and its effect on community

The main aim of this paper is to analysis the effect of sleep disorders on the community. This study is quantitative. The questionnaire was designed and distributed among the student in school in the city of Riyadh high and intermediate school. The sample of this study consist 100 students. The researcher visited a school in the city of Riyadh high and intermediate school sections and that on December 10 to 11 to measure the impact of sleep disorders through a questionnaire that measures the effects of lack of sleep and then make them aware of the benefits of sleep and harm of lack of sleep from the physical and psychological effects, and it gave a lecture educate the students and then distribute them brochure contain the benefits and harmful effects of sleep. SPSS 21 was used to analysis that data. The results of the study indicated that lack of sleep limits a person's ability to think and solve the problem effectively, which means that people who wake up for a long time influence them to learn at an effective level. Lack of sleep affects the ability of thinking and can limit your ability to accurately interpret events, which can be difficult to respond correctly to situations in which effective decision-making is intelligent. The lack of sleep, even for one night can lead to swelling of the eyes and turn the skin into pale skin. Keywords: Sleep disorders, community

AN OVERVIEW OF PHARMACODYNAMIC PROPERTIES OF INHALED CORTICOSTEROIDS

This article was aimed to review the pharmacodynamic of inhaled corticosteroids, by conducting search throughout the literature, using the PubMed and Medline, including all relevant studies that were published to beginning of 2022. The PK and PD properties of ICSs used to treat asthma, as well as the significance of their interactions, have been studied. When prescribing an ICS to an asthmatic patient, the differences in PK and PD must be considered because a better understanding of the PK/PD interrelationship of ICSs may be important to better fit with the between-patient variability and within-patient repeatability in the response to ICSs, which frequently complicate the therapeutic approach to the asthmatic patient