Frequency of Null Phenotypes of Glutathione S-Transferase M1 and T1 among the Populations of Tabuk (Northwestern Part of Saudi Arabia)

Background: The variability in the distribution of the null phenotypes of GSTM1 and GSTT1, due to total or partial gene deletion resulting in the lack of the active enzyme, has been reported in different populations, especially in ethnically well-defined groups but not in Tabuk. This study investigated the variability in the distribution of the null phenotypes of GSTM1 and GSTT1 in the population of Tabuk (northwestern part of Saudi Arabia). Method: This study was conducted on 200 subjects of Tabuk—northwestern part of Saudi Arabia among which 100 were chronic smokers and 100 were nonsmokers. The subjects were reporting to hospital for routine checkup. All were without past history of any chronic disease and no significant abnormality. GST genotyping was done by multiplex PCR-based methods. The smoker and control groups were compared using a chi-square test with P GSTM1 deletion homozygosity of 14% and 1% was reported among non smokers and smokers, respectively whereas GSTT1 deletion homozygosity of 28% and 6% was reported among non smokers and smokers, respectively. Our results indicate that there are major differences in allelic distribution of GSTM1 and GSTT1 genes between the two groups investigated. Combined analysis of both genes revealed that 15% of smokers and non smokers harbor the deleted genotype of GSTM1 and 34% of smokers and non smokers harbor the deleted genotype of GSTT1 with significant differences. Conclusion: This study enables selecting subgroups among the general population who are more susceptible to DNA damage and will help genetic studies on the association of GST polymorphisms with disease risks and drug effects in Arab population. Studies with a larger sample size are needed to evaluate and confirm the validity of our results.

Seismic Hazard Assessment for Tabuk City, NW Saudi Arabia

Tabuk city is located within the Red Sea and Gulf of Aqaba active tectonic environment where it has ex- perienced considerable earthquakes in the historical and instrumental period. Recently, Tabuk city is ex- pected to become one of the future economic communities in Saudi Arabia. Accordingly, assessment of seismic hazard of Tabuk city plays an important role to minimize earthquake damage and to anticipate the future safe development for the strategic projects. For this purposes, earthquake data were collected from local and regional data centers to construct earthquake catalogue. The earthquake source zones that affect Tabuk city, maximum magnitude and closest distance have been identified. The stochastic approach has been applied through this study for seismic hazard assessment in terms of peak ground acceleration and the response spectra. The results illustrated that, the maximum peak ground acceleration resulted from Tabuk source zone with moment magnitude (Mw) of 7.5. The calculated peak ground acceleration of218 cm/sec2 at distance of10 KmforTabukCityat the bedrock. The response spectra of Pseudo-Spectral Acceleration (PSA) have been calculated at 5% of the critical damping with a value of470 cm/sec2 at10 Kmdistance. The results of the present study are highly recommended to improve Saudi Building Code (SBC) for earthquake resistant design in Tabuk city.

Integrating Geotechnical Investigation with Hydrological Modeling for Mitigation of Expansive Soil Hazards in Tabuk City, Saudi Arabia

Due to global climatic changes, flash floods are followed as a yearly disaster with high magnitude of influence. During the years 1981, 1988, 2010, 2012 and in January 2013, Tabuk city, northwest of Saudi Arabia suffered huge flash floods. These are major factors affecting on the swelling behavior of expansive Tabuk shale. The examined geotechnical properties of the surface and subsurface lithology of the sedimentary deposits distinguished Tabuk city into three zones. The expansive zone is spread in the middle and the non-expansive zones are distributed in the east and west of the city. The Watershed Modeling System (WMS) and Hydrologic Engineering Center (HEC-1) models were used to delineate and identify the drainage system and basin morphometry, where flash floods and accumulation of water might take place. Integration between geotechnical distribution maps of the expansion soil and surface hydrological data in terms of runoff maps was done. It has been identified the whereabouts the soils which have expansion characteristics and areas prone to flooding and surface runoff. They are helpful in defining the hazard zones map. Based on this map, it can be avoided constructions on the risk neighborhoods such as Al Qadsiyah, Al Maseif, Arrwdah, Al Nakhil and Al Rajhi. Also, it can suggest that the western side of Tabuk city is suitable for future urban extension. These results will help planners and citizens to create alternative development scenarios and determine their impact on the future urbanization patterns. Moreover, the direction of surface runoff flow or storm water discharge should be away from the expansion soil areas. Therefore, constructing dams on the outlet of the high-risk basins, south of Tabuk city is an important solution to control flash flood events, as well as increase groundwater recharge.

Power Quality Study of an Isolated Northwest Grid of Saudi Arabia with PV and Storage

One main concern of power quality is harmonics because the distorted waveforms of current and voltage have a huge effect on electrical equipment. Due to the continuous increase of grid connected photovoltaic (PV) and nonlinear loads, as a result of the fast development and growth of power electronics application, power quality becomes more important since it introduces harmonics to the power system. This paper presents a power quality study to the isolated northwest grid of Saudi Arabia in presence of PV system and battery storage. Moreover, the study includes nonlinear loads for more analysis regarding harmonics penetration and the design procedure for passive filters to eliminate the harmonics.

The Impact of Age and Gender on Severity and Types of Periodontal Diseases among Patients from Two Regions in Saudi Arabia

Background: Periodontitis is the predominant disease in the oral cavity and there are alterations in the periodontal tissues associated with the aging and gender of the patient. Objective: The present study was designed to assess the impact of age and gender of the patient on severity and types of periodontal diseases among patients from two regions in Saudi Arabia. Materials and Methods: The current study was done on 600 Saudi patients from Aseer and Tabuk regions in Saudi Arabia (50% males and 50% females) and divided into three equal groups (n = 200) according to the patients age: children and young patients (1 - 24 years old), adults patients (25 - 64 years old) and seniors patients (more than 65 years old). Plaque index (PLI), gingival index (GI), periodontal pocket depth (PPD) and clinical attachment loss (CAL) were recorded from all participants. The data were collected and analyzed with SPSS to determine the mean and standard deviation (±SD) and the values of significance (P ≤ 0.005). Results: The results of the present study revealed that 340 patients (56.7%) were affected with gingivitis dental biofilm induced and 260 patients were affected by periodontitis. Gingivitis dental biofilm-induced is especially detected in children and young patients (33.3%), adult patients (16.7%) and seniors patients (6.7%) whereas periodontitis cases were seen among the adult and seniors patients (16.7%) and (26.6%) respectively. Furthermore, the present study displayed the higher severity and prevalence of gingivitis dental biofilm-induced and periodontitis among females more than males in group II and group III maybe due to hormonal changes. The present study saw that there are statistically significant differences in clinical findings in the comparison between groups of this study (P ≤ 0.005). Conclusion: We conclude that there is a relation between severity and types of periodontal diseases and the ages and genders of Saudi patients in Aseer and Tabuk regions, Saudi Arabia.