Background: The coronavirus disease (COVID-19) pandemic is an international public health threat. This study aimed to evaluate COVID-19-related knowledge, preventive behaviors, and risk perception among Saudi Arabian medical students and interns. Materials and Methods: This cross-sectional study was conducted among fourth- and fifth-year medical students and interns between June and August 2020 at three colleges of medicine in Qassim Region, Saudi Arabia. A previously validated questionnaire was distributed as an online survey. Results: The total mean knowledge score was 12.5/15 points; 83.9% achieved a high score. The mean score of self-reported preventive behavior was 8.40; 94.1% achieved a high score. The overall mean risk perception score was 5.34/8 points; 31.6% achieved a high score. Conclusion: Medical students assessed in this study displayed sufficient knowledge and preventive behaviors regarding the COVID-19 pandemic and an average level of risk perception. Lower scores by younger medical students suggest that they must improve their COVID-19 knowledge and risk perception, as they are a potential source of health information in their communities.

The oxidation of NO, CO and hydrocarbons (HC) individually, in mixtures, and with NO2 were investigated over a monolith‐supported Pt/Al2O3 catalyst under oxidising conditions. Although competitive adsorption and inhibition by other species on oxidation reactions is a relatively well‐known phenomenon, this study represents a more comprehensive examination of such effects between key components in vehicle exhaust gases. NO2 was completely reduced by CO and C3H6, under NO2 limited conditions, at temperatures as low as 110°C and at temperatures above 140°C with dodecane and m‐xylene. NO2 was then again observed once the extent of oxidation of the other species by oxygen was significant. Under the conditions tested, NO, CO and HC oxidation was inhibited by NO2 in the feed gas mixture. HC were also found to inhibit the oxidation of NO and other HC species due to site adsorption competition. For CO, HC did not change the onset of oxidation, but did inhibit the extent after their light off began. At low temperatures, CO was initially found to inhibit NO oxidation, but at higher temperatures, once CO oxidation was significant, CO promoted NO conversion to NO2. The observed inhibition effects of the different gases on HC oxidation were not additive, indicating one species would cause inhibition, but once its inhibition ended, another species could still then cause inhibition. The combined effect of C3H6, NO and NO2 on CO conversion was found to be additive. This is because CO oxidation started prior C3H6. © 2011 Canadian Society for Chemical Engineering

a b s t r a c tThe Gulf Cooperation Council (GCC) countries are situated in one of the most arid regions in the world, with extremely poor endowment of freshwater resources. Despite the water scarcity, the GCC countries have done well in providing water for their ever-increasing population and rapidly expanding economic base. However, this has been achieved only by resorting to relatively very expensive and costly investments in water supply sources and infrastructures manifested by desalination, water treatment, dam constructions, as well as groundwater overdrafting. Being an important vector for socioeconomic development, there is a need for the establishment of an efficient and sustainable water management system to ensure that the water sector can continue to serve the countries' development needs. However, currently the GCC countries are facing several major challenges that are threatening the water sector sustainability. These include increasing water scarcity, increasing costs for infrastructure and service delivery, resources deterioration, increasing environmental and economic externalities, and many others. The main driving forces of these challenges are population growth and changing consumption patterns, low supply efficiencies, lower rates of water reuse and recycling, and low energy efficiency in the water sector. The intensity of these challenges is expected to increase in the future due to the additional driving force of the impacts of climate change. Realizing these challenges, the GCC Supreme Council has issued in its 31st summit (2010) the directive of "serious and speedy steps should be taken and endorsed by the GCC Supreme Council toward a long-term comprehensive Gulf water strategy". In 2016, a GCC Unified Water Strategy, 2016-2035 (GCC UWS) has been finalized by the GCC Secretariat General and approved by the GCC Supreme Council. This paper presents the main challenges facing the sustainability of the water sector in the GCC countries, the formulated GCC UWS (main themes and strategic objectives and their policies, key performance indicators and targets), the potential financial, economic, and environmental benefits from its implementation, and its expected overall contribution to the water sector sustainability in the GCC countries.

No abstract

No abstract