مراجعة كتاب الكتابة التحليلية

This work addresses a review of a book Writing Analytically. The book presents a number of issues related to improving the writing of scientific research and academic work in light of the requirements of academic stages and various fields of scientific publishing. This book is primarily concerned with providing rich material for academic writing in English.في هذه المراجعة يتم استعراض كتاب الكتابة التحليلية، الكتاب من تأليف ديفيد روزن واسر وجيل استيفن من كلية مولن بيرج، تم نشره بواسطة مؤسسة وادسورث عام ٢٠١٢، وهذا هو الإصدار السادس للكتاب. في هذه الورقة سيتم مراجعة الكتاب في ضوء مبادئ الكتابة التحليلية المذكورة في جميع أنحاء الكتاب نفسه. الكلمات الدلالية: الكتابة التحليلية، تعليم الكتاب

A Survey on Usage of Rubber Dam during Composite Restorative Procedures by General and Specialist Dental Practitioners in Saudi Arabia

Aim: The purpose of this study was to quantify the usage of rubber dam (RD) among general and specialty dental practitioners during composite restorative procedures in SaudiArabia. Materials and methods: A cross-sectional questionnaire-based study was conducted from March to April 2012 in association with Saudi Dental Society on 306 general dental practitioners (GP), dentists specialized in operative dentistry (OD) and other specialty dentists (OSD). The collected data were analyzed using Microsoft Excel 2010 program and descriptive statistics were obtained. Results: For isolation during composite restorative procedures in anterior teeth, 21.2% of GP, 57.1% of OD and 29.6% of OSD use RD; 77.5% of GP, 42.9% of OD and 68.5% of OSD use cotton rolls and 1.3% of GP and 1.9% of OSD use methods other than RD or cotton rolls. For isolation during composite restorative procedures in posterior teeth, 28.8% of GP, 62.5% of OD and 40.7% of OSD use RD; 68.7% of GP, 35.7% of OD and 57.4% of OSD use cotton rolls and 2.5% of GP, 1.8% of OD and 1.9% of OSD use other methods. Conclusion: There is under-usage of RD during placement of composite restorations by dentists in the study population. Majority of the dentists practicing RD are those who have specialized in OD

EFFECT OF THE POSITIONING OF MULTIPLE CHARGING STATIONS FOR ELECTRIC VEHICLES ON GRID PERFORMANCE IN SAUDI ARABIA: THE CASE OF JEDDAH CITY

Electric vehicles (EV) have several advantages over traditional internal combustion vehicles, including lower local pollution, increased energy efficiency, and reduced reliance on oil. However, in many countries, such as Saudi Arabia (SA), considerable impediments to EV exist, including a lack of charging stations. What will happen as the future government strategy is to add a large number of charging stations in this country, and what effect will this have on the grid, particularly during the charging phase? The purpose of this research is to determine the power grid's capability in Saudi Arabia to house extra demand for EV charging. This research should aid in maintaining system stability and better planning for the future EV charging infrastructure. This paper aims to outline the effect of charging EVs on the grid and predict the possible number of charging stations that can be installed for a shopping mall parking space in Jeddah city. The data were collected from daily energy consumption and energy peak demand records from a shopping mall substation, and a total of eight EV charging scenarios were simulated. The load profile was analyzed for all scenarios, and as a result, 100% and 41% charging capacities are recommended for slow and fast charging methods, respectively

DESIGN, EXPRESSION AND PURIFICATION OF FUNCTIONAL HUMAN CANNABINOID RECEPTOR 2

Cannabinoid receptors (CB1 and CB2) are GPCRs that belong to the rhodopsin-like family. Recent studies have demonstrated a role for CB2 in attenuating bone cancer-induced pain, reducing microglial activation in Alzheimer’s disease, and regulating bone mass in osteoporosis. As such, there is an urgent need for the development of new therapeutic agents targeting CB2. However, structure- or fragment-based in silico drug design is hampered by the absence of 3D structural information on CB2, because of its inherent structural complexity. Recently, it has been shown that specific residues of CB2 (in transmembrane helices III, V, VII and extracellular loop 2) play crucial roles in the binding of the vast majority of cannabinoid ligands. In this report, we performed computer modeling along with site-directed mutagenesis studies and the results suggest that four residues that lie within these regions have a novel importance for receptor recognition of compound XIE95-26, a discovered CB2 inverse agonist in our lab, and known cannabinoid ligands CP-55940 (agonist) and SR144528 (inverse agonist). These mutant CB2 receptors were characterized by western blot, and ligand binding studies. Moreover, functional assays were performed for some mutant CB2 receptor to illustrate the role of altered residues in downstream signaling. Next, we’ve taken further steps to provide a genetically modified functional CB2 for biophysical and biochemical studies with the goal of improving the current purification methodology for the production of chimeric CB2 fusion proteins from the baculovirus system. By introducing a fusion protein and rational modifications to the chimeric receptor, investigators endeavoring to purify other GPCRs have overcome the challenge of obtaining sufficient stable protein for structural studies. Thus, different generations of truncated CB2 receptor were obtained to assess any improvements in receptor expression. Receptor expression and ligand binding capacity were assessed as criteria for pilot scale purification and for detergent selection. The best constructs were subjected to the optimal purification scheme using immobilized metal affinity, anti-M2 affinity, and size exclusion chromatography steps. Collectively, results from this study will provide insights into the structure and functional mechanisms of CB2 and facilitate the design of small molecules that influence CB2 signaling behavior

Development of a new actinometric method for polychromatic light irradiation. Application to photochromes, drugs and stilbenoids

The photostability data of chemical species is usually described based upon models using equations applicable to standard zero-, first- or second-order kinetics (classical thermal order kinetics) and other such models. These thermal order kinetic models have certain limitations, however, regarding parameter representation of the photoreaction and the reproducibility of associated results. The other models available in the literature use approximation and expansion methods to solve the photochemical rate law but are unfortunately unable to provide robust models to describe the photochemical reaction itself. This research resolves many of the drawbacks typically encountered within the photokinetics domain by improving upon an existing model and designing new models that describe photochemical reactions in solution. These models are the Φ- and n-order kinetics. The former reduces the number of elucidation method steps whilst the latter is designed to describe photochemical reactions under irradiation by polychromatic light for three chosen AB reaction systems. In the development of the above-mentioned methodologies, this research selects species based on their photochemical reaction mechanisms to study their photodegradation, starting from a simple to a complex mechanism. These compounds are: C-DAE for unimolecular AB 〖(1Φ)〗_(ε_(B=0) ), nifedipine and dacarbazine for unimolecular AB〖(1Φ)〗_(ε_(B≠0) ), and the stilbenoids group, axibinib and O-DAE for photoreversible AB (2Φ) reactions. The results obtained in this research show that the Φ-order kinetics approach offers a good description of the photodegradation of these species under continuous monochromatic irradiation. It has been established that both the forward (Φ(A→B)) and reverse (Φ(B→A)) quantum yields increased with increasing irradiation wavelength according to a sigmoid pattern. Additionally, this study presents a methodology to calculate the β factor, which is used to obtain the photoreactivity of the species, in a method that offers a much simpler and faster approach to this determination than traditional methods. The stilbenoids group shows higher photoreactivity than the other species studied according to the β factor ranking scale. Other methods were designed to overcome the drawbacks to describing a photochemical reaction under irradiation by polychromatic light. The validity of the new mathematical models (Φ- and n-order) were verified using simulation studies through numerical integration methods (NIMs) to generate simulated cases for each photochemical reaction system considered. In addition, the Φ- and n-order models were examined and validated using experimental HPLC and spectrophotometry photodegradation data obtained for different species under irradiation by polychromatic light. Results obtained in this study confirm the model’s predictions, as both photoreaction rate constant and initial reaction velocity (υ(0)) were observed to remain constant with variable initial concentrations of the species considered. Furthermore, actinometric methods were developed and applied to study the photochemical reaction of species in solution under irradiation by monochromatic and polychromatic light. The former and latter were developed to determine the light intensity of unknown light sources. Monochromatic light has a much smaller wavelength distribution than polychromatic, which are determined based on the associated β factors. The results show that each method can be used independently to quantify the light intensities from different light sources

Students' and teachers' perspectives towards the use of social media technologies as a supportive learning tool in English language classes: A case study from a university in Saudi Arabia

This study examined students’ and English language instructors' attitudes towards using social media technologies to support English language learning and teaching at the University of Bisha, Blagran campuses, College of Science and Arts in Saudi Arabia. While this phenomenon has been researched for many years, relatively little is known about the role of social media technologies to support English language learning from both the students' and English instructors' lenses; or, about the factors that may influence the use of these technological tools, and the conditions required for the successful use of these tools. Through a review of the current empirical and theoretical literature, this research aims to provide a clear understanding for the Ministry of Education in Saudi Arabia of some potential roles that social media technologies could play in enhancing the English language learning environment within the kingdom. The participants in this study were English language undergraduate students, along with their English language instructors. Mixed methods were used to gather the data (survey, focus groups, interviews). Two hundred and twenty-two students completed the survey (101 male and 121 female). Forty students (20 male and 20 female) participated in the focus groups. The survey and focus groups were used convergently to provide a rich understanding of the students' attitudes. Semi-structured interviews were used with the English language instructors, a total of eighteen (8 male- 10 female), to examine their attitudes in-depth and allow them to reveal their stances on using such technological tools in supporting English language teaching. The findings from the survey indicated that the students showed positive attitudes to use social media technologies to support English language learning with a mean (M=4.09, SD =.93). There was a significant difference between male and female students' attitudes in using social media technologies to support English language learning. Females mean scores were all higher than males and exhibited less dispersion as illustrated by the standard deviations. The difference in overall mean scores by gender was significant (p<0.05). Also, YouTube was the most social media technologies used by the students to support their English language learning. All the suggested predictors, including Perceived Usefulness, Perceived Ease of Use, Subjective Norms, and Gender were significant determinants of the students' attitudes. Also, overall the students stated that social media technologies could be useful tools in supporting their English language learning. These technological tools could be seen as a reference tool to familiarise the students with new vocabulary and English varieties. Also, the students stated that using these technological tools to support English learning could make the language learning process more comfortable and enjoyable because it can suit different language learning preferences and reduce classroom anxiety. The students also stated that using social media allowed them to socialise and speak English with people around the world. As far as the instructors' responses are concerned, their overall attitudes were positive. They stated that social media are familiar tools to the students, can make learning English more comfortable, and could create an enjoyable learning environment. However, some potential concerns were raised, such as losing control of the classes, cultural norms effect, language complexity, and a possible negative impact on learning motivation. The majority of the instructors agreed that technology competence could be an obstacle facing some instructors in terms of using social media technologies to support their English language teaching. They also agreed that they often lack administrative support and the college's infrastructure administration could be barriers to adopting social media technologies. Future suggestions included using social media technologies as supportive or scaffolding tools in English learning and the integration of some activities from social media into the English curriculum were made by the instructors for successful adoption of social media to support English language teaching. Some tentative implications might be drawn from this study. It provided a rich insight into the use of social media technologies to support English language learning and teaching via student and teacher lenses. These insights have practical benefits for educational administrators and instructors in Saudi Arabia. However, more research on exploring students' and instructors' attitudes is needed with a greater consideration of the impact of gender and age differences

Simultaneous estimation of cinnamaldehyde and eugenol in essential oils and traditional and ultrasound-assisted extracts of different species of cinnamon using a sustainable/green HPTLC technique

A wide range of analytical techniques are reported for the determination of cinnamaldehyde (CCHO) and eugenol (EOH) in plant extracts and herbal formulations either alone or in combination. Nevertheless, sustainable/green analytical techniques for the estimation of CCHO and EOH either alone or in combination are scarce in the literature. Accordingly, the present research was carried out to establish a rapid, highly sensitive, and sustainable high-performance thin-layer chromatography (HPTLC) technique for the simultaneous estimation of CCHO and EOH in the traditional and ultrasound-assisted methanolic extracts of Cinnamomum zeylanicum, C. burmannii, and C. cassia and their essential oils. The simultaneous estimation of CCHO and EOH was performed through NP-18 silica gel 60 F254S HPTLC plates. The cyclohexane/ethyl acetate (90:10, v v−1) solvent system was optimized as the mobile phase for the simultaneous estimation of CCHO and EOH. The greenness score of the HPTLC technique was predicted using AGREE software. The entire analysis was carried out at a detection wavelength of 296 nm for CCHO and EOH. The sustainable HPTLC technique was observed as linear in the range 10–2000 ng band−1 for CCHO and EOH. The proposed technique was found to be highly sensitive, rapid, accurate, precise, and robust for the simultaneous estimation of CCHO and EOH. The content of CCHO in traditional methanolic extracts of C. zeylanicum, C. burmannii, and C. cassia was found to be 96.36, 118.49, and 114.18 mg g−1, respectively. However, the content of CCHO in ultrasound-assisted methanolic extracts of C. zeylanicum, C. burmannii, and C. cassia was found to be 111.57, 134.39, and 129.07 mg g−1, respectively. The content of CCHO in essential oils of C. zeylanicum, C. burmannii, and C. cassia was found to be 191.20, 214.24, and 202.09 mg g−1, respectively. The content of EOH in traditional methanolic extracts of C. zeylanicum, C. burmannii, and C. cassia was found to be 73.38, 165.41, and 109.10 mg g−1, respectively. However, the content of EOH in ultrasound-assisted methanolic extracts of C. zeylanicum, C. burmannii, and C. cassia was found to be 87.20, 218.09, and 121.85 mg g−1, respectively. The content of EOH in essential oils of C. zeylanicum, C. burmannii, and C. cassia was found to be 61.26, 79.21, and 69.02 mg g−1, respectively. The amounts of CCHO and EOH were found to be significantly higher in ultrasound-assisted extracts of all species compared to its traditional extraction and hence ultrasound extraction has been proposed as a superior technique for the extraction of CCHO and EOH. The AGREE analytical score of the present analytical technique was predicted as 0.75, suggesting excellent greenness profile of the proposed analytical technique. Based on all these observations and results, the proposed sustainable HPTLC technique can be successfully used for the simultaneous estimation of CCHO and EOH in different plant extracts and herbal products

Nesting Biology of the Leafcutting Bee Megachile minutissima (Hymenoptera: Megachilidae) in Central Saudi Arabia

The leafcutting bee Megachile (Eutricharaea) minutissima Radoszkowski is a widely distributed species in the Middle East and a promising pollinator of alfalfa. We provide information on the nest architecture, foraging behavior, phenology, and host plants of a wild population of M. minutissima studied between March 2010 and September 2012 in Amariah, a typical desert in central Saudi Arabia. Bees nested in preexisting cavities in the sandy, dry, and loose soil, and built between 2 and 14 leaf-lined brood cells per nest. Females built and provisioned 1-2 cells per day, each consisting of a large oval piece from which the cell cup was made and a small semiround piece that was used as cell cap; however, occasionally small oval pieces were also used in the latter. Cells were built from leaves of Ricinus communis L. (Euphorbiaceae), a locally abundant plant. Both sexes were captured from March to October at flowers of 11 species (10 families), indicating some degree of polylecty as well as either bivoltinism or multivoltinism. We also provide comparative taxonomic comments that will assist bee researchers to easily recognize this species

A new species of Chalicodoma from Saudi Arabia with modified facial setae (Hymenoptera, Megachilidae)

Some bees and pollen wasps have independently evolved simple, stiff, erect, apically-curved, curly or hooked facial setae as adaptations to collect pollen from nototribic flowers. A distinctive new species of Chalicodoma Lepeletier de Saint Fargeau subgenus Pseudomegachile Friese from Saudi Arabia with such morphological adaptations, C. riyadhense sp. n., is described and figured. The species was captured visiting flowers of Blepharis ciliaris (L.) (Acanthaceae). The occurrence of modified facial setae is documented and discussed for the first time in eight other species of Pseudomegachile, and a key to the genera and subgenera of Megachilini currently confirmed for Saudi Arabia is provided