Assessment of Heavy Metal Contamination in the Soils of the Gulf of Aqaba (Northwestern Saudi Arabia): Integration of Geochemical, Remote Sensing, GIS, and Statistical Data

Ghrefat, H.; Zaman, H.; Batayneh, A.; El Waheidi, M.M.; Qaysi, S.; Al-Taani, A.; Jallouli, C., and Badhris, O., 2021. Assessment of heavy metal contamination in the soils of the Gulf of Aqaba (Northwestern Saudi Arabia): Integration of geochemical, remote sensing, GIS, and statistical data. Journal of Coastal Research, 37(4), 864872. Coconut Creek (Florida), ISSN 0749-0208. Rock and soil sample geochemical analysis was conducted to investigate the extent and causes of soil contamination in the Gulf of Aqaba region in NW Saudi Arabia. The inductively coupled plasma mass spectrometry was used to determine the concentrations of Pb, Zn, Cu, Co, Cr, Mn, Fe, Hg, Mo, and Cd in 23 soil samples and 25 samples from granitic and Cenozoic marine sedimentary formations. The geochemical results have been integrated with remote sensing, GIS, and statistical analysis to assess the severity of soil pollution in the area. The concentrations of heavy metals (ppm) in the collected soil samples were as follows: Fe (2259.70), Mn (101.85), Zn (20.15), Pb (10.74), Cr (8.67), Cu (6.10), Co (1.35), Mo (0.69), Hg (0.30), and Cd (0.17). A significant variation in the mean metal concentrations was observed for the rock samples. The correlation analysis results showed that different degrees of positive and negative relationships exist among different metals in the area. Two factors (PC1 and PC2) were identified using the principal component analysis (PCA) and were responsible for about 60% of the total variance in the data. The studied metals were separated and classified into two factors based on their geochemical features and source. In contrast, the hierarchical cluster analysis grouped the identified metals into different groups based on the similarity of their characteristics. The principal component (PC2) applied to the Sentinel-2A image classified the land cover in the area into three classes: vegetation, barren rocks, and urban area. The enrichment factor shows a relatively higher percentage of enriched Mo; however, the indices of geo-accumulation and potential ecological risk generally reveal no substantial metallic contamination in the study area. The main sources of soil contamination with metals are rock-weathering processes and various agricultural works that are widely practiced in the area

Conceptual Design of a Single DOF Human-Like Eight-Bar Leg Mechanism

Abstract Legs are the most important elements for accomplishing human physical work including transportation or displacement. The article presents a mechanical reproduction of the human walking apparatus. Using design rules, a final mechanism configuration is achieved such that the crank is a binary link connected to a binary ground link. The resulting linkage is a single degree-of-freedom (DOF) eight-bar mechanism. The mechanism exemplifies the shape and movement of a human leg. The mechanism is simulated and tested to verify the proposed synthesis

Allergic Rhinitis and Self- Reported Allergic Diseases in Doctor- Diagnosed Attention Deficit Hyperactivity Disorder (ADHD) Paediatric Patients

Allergic rhiniti

Multivariate statistical analysis of urban soil contamination by heavy metals at selected industrial locations in the Greater Toronto area, Canada

A good understanding of urban soil contamination with metals and the location of pollution sources due to industrialization and urbanization is important for addressing many environmental problems. The results are reported here of an analysis of the metals content in urban soils samples next toindustrial locations in the Greater Toronto Area (GTA) in Ontario, Canada. Theanalyzed metals are Cr, Mn, Fe, Ni, Cu, Zn, and Pb. Multivariate geostatistcalanalysis (correlation matrix, cluster analysis, principal component analysis) is used to estimate soil chemical content variability. The correlation matrix exhibits a positive correlation with Mn, Fe, Cu, Zn, Cd, and Pb. The principal component analysis (PCA) displays two components. The first component explains the major part of the total variance and is loaded heavily with Cr, Mn, Fe, Zn,and Pb, and the sources are industrial activities and traffic flows. The second component is loaded with Ni, and Cd, and the sources could be lithology andtraffic flow. The results of the cluster analysis demonstrate three major clusters: 1) Mn-Zn, 2) Pb-Cd-Cu and Cr, 3) Fe-Ni. The geo-accumulation index and the pollution load index are determined and show the main I geovalues to be in the range of 0-1.67; the values indicate that the soil samples studied for industrial locations in the GTA are slightly to moderately contaminated with Cr, Fe, Cu, Zn, and Cd, and moderately contaminated with Pb,while Ni, and Mn fall in class "0". Regarding the pollution load ingindex (PLI), the lowest values are observed at stations 6, 7, 9, 10, 11, 12,25, 27 and 28, while the highest values are recorded for stations 1, 5, 6, 13,14, 16, 17, 18, 20, 22 and 24, and very high PLI readings are seen for stations 5, 13, 16, 17, 18, 22 and 24. These data confirm that the type of industries, especially metallurgical and chemical related ones, in the study area, in addition to high traffic flows, are the main sources for soil pollution in the GTA

Synthesis, Characterization, and Assessment of Anti-Cancer Potential of ZnO Nanoparticles in an In Vitro Model of Breast Cancer

Advanced innovations for combating variants of aggressive breast cancer and overcoming drug resistance are desired. In cancer treatment, ZnO nanoparticles (NPs) have the capacity to specifically and compellingly activate apoptosis of cancer cells. There is also a pressing need to develop innovative anti-cancer therapeutics, and recent research suggests that ZnO nanoparticles hold great potential. Here, the in vitro chemical effectiveness of ZnO NPs has been tested. Zinc oxide (ZnO) nanoparticles were synthesized using Citrullus colocynthis (L.) Schrad by green methods approach. The generated ZnO was observed to have a hexagonal wurtzite crystal arrangement. The generated nanomaterials were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), UV-visible spectroscopy. The crystallinity of ZnO was reported to be in the range 50–60 nm. The NPs morphology showed a strong absorbance at 374 nm with an estimated gap band of 3.20 eV to 3.32 eV. Microscopy analysis proved the morphology and distribution of the generated nanoparticles to be around 50 nm, with the elemental studies showing the elemental composition of ZnO and further confirming the purity of ZnO NPs. The cytotoxic effect of ZnO NPs was evaluated against wild-type and doxorubicin-resistant MCF-7 and MDA-MB-231 breast cancer cell lines. The results showed the ability of ZnO NPs to inhibit the prefoliation of MCF-7 and MDA-MB-231 prefoliation through the induction of apoptosis without significant differences in both wild-type and resistance to doxorubicin

Symptomatic dry eye disease among university students

Background: Dry eye disease (DED) is a multifactorial condition often characterized by a reduction in tear film quantity or quality. This study aimed to determine the frequency of DED and its associated subjective symptoms among students of Mu’tah University. Methods: In this cross-sectional study conducted at Mu’tah University, Mu’tah, Jordan, from January to April 2022, 489 students completed an online patient-reported DED symptom questionnaire and the ocular surface disease index (OSDI) questionnaire. Moreover, 106 participants underwent clinical examinations using the Schirmer test I and fluorescein tear breakup time (TBUT). Results: Approximately 74.6% of the students self-reported experiencing DED symptoms, and 72.6% had an OSDI score > 12, which is considered the threshold for an abnormal ocular surface. Clinical examinations revealed low Schirmer test scores (< 10 mm) in 26.4% (n = 28) and 25.5% (n = 27) of the right and left eyes, respectively. We observed low TBUT scores (< 5 s) in 19.8% (n = 21) and 18.9% (n = 20) of the right and left eyes, respectively. We noted significant differences between the self-reported DED symptoms and the Schirmer test scores (P = 0.003 for both right and left eyes), TBUT (P < 0.001 for both right and left eyes), and OSDI score (P < 0.001 for each self-reported DED symptom). We observed a weak significant positive correlation between Schirmer test scores and TBUT in the right (r = + 0.30; P = 0.002) and left (r = + 0.34; P < 0.001) eyes; a negligible significant inverse correlation between OSDI scores and Schirmer test scores in the right (r = - 0.24; P = 0.013) and left (r = - 0.23; P = 0.019) eyes; and a negligible significant inverse correlation between the OSDI score and TBUT of the left eye (r = - 0.25; P = 0.011) but not of the right eye (r = - 0.17; P = 0.077). Conclusions: The frequency of DED symptoms in this study was higher than that previously reported based on foreign statistics. The presence of self-reported DED symptoms was significantly associated with higher OSDI scores. Self-reported DED symptoms were more frequent than the abnormalities detected using objective methods. Therefore, a combination of subjective and objective measures may provide a higher diagnostic yield for DED. Further studies are required to confirm this hypothesis

Association between early childhood caries and poverty in low and middle income countries

Background: The aim of this study was to assess the relationship between early childhood caries (ECC) in 3–5-year-old children, seven indicators of poverty and the indicator of monetary poverty in low- and middle-income countries (LICs, MICs). Methods: This ecologic study utilized 2007 to 2017 country-level data for LICs and MICs. Explanatory variables were seven indicators of poverty namely food, water, sanitation, health, shelter, access to information, education; and monetary poverty. The outcome variable was the percentage of 3–5-year-old children with ECC. A series of univariate general linear regression models were used to assess the relationship between the percentage of 3–5 year-old children with ECC and each of the seven indicators of poverty, and monetary poverty. This was followed by multivariable regression models to determined the combined effect of the seven indicators of poverty, as well as the combined effect of the seven indicators of poverty and monetary poverty. Adjusted R2 measured models’ ability to explain the variation among LICs and MICs in the percentage of 3–5-year-old children with ECC. Results: Significantly more people had food, sanitation, shelter, access to information, education and monetary poverty in LICs than in MICs. There was no difference in the prevalence of ECC in 3–5-year-old children between LICs and MICs. The combination of the seven indicators of poverty explained 15% of the variation in the percentage of 3–5-year-old children with ECC compared to 1% explained by monetary poverty. When the seven indicators of poverty and the indicator for monetary poverty were combined, the amount of variation explained by them was 10%. Only two of the poverty indicators had a direct relationship with the percentage of children with ECC; there was a higher percentage of ECC in countries with higher percentage of population living in slums (B = 0.35) and in those countries with higher percentage of the population living below poverty lines (B = 0.19). The other indicators had an inverse relationship. Conclusion: The use of multiple indicators to measures of poverty explained greater amount of variation in the percentage of 3–5-year-olds with ECC in LICs and MICs than using only the indicator for monetary poverty.publishedVersio

Governance, maternal well-being and early childhood caries in 3-5-year-old children

BACKGROUND: This study assessed the direct, indirect and total effect of distal - political - risk indicators (affecting populations), and proximal risk indicators (affecting women) on the global prevalence of early childhood caries (ECC) in 3-5 year old children. METHODS: Data on global ECC prevalence were obtained from a prior study. Data for distal risk indicators (voice and accountability; political stability/absence of terrorism; control of corruption) were obtained from the World Bank Governance indicators, 2016. Data for proximal risk indicators (women's opportunity for leadership; percentage of female legislators, top officials and managers; basic employability status of women; ability of women to afford time off work to care for newborns; gross national income (GNI) per capita for females) were derived from the Human Development Index, 2016. Associations between variables were assessed with path analysis. RESULTS: Voice and accountability (β = - 0.60) and GNI per capita for females (β = - 0.33) were directly associated with a lower ECC prevalence. Political stability/absence of terrorism (β =0.40) and higher percentage of female legislators, senior officials and managers (β = 0.18) were directly associated with a higher ECC prevalence. Control of corruption (β = - 0.23) was indirectly associated with a lower ECC prevalence. Voice and accountability (β = 0.12) was indirectly associated with a higher ECC prevalence. Overall, voice and accountability (β = - 0.49), political stability/absence of terrorism (β = 0.34) and higher female GNI (β = - 0.33) had the greatest effects on ECC prevalence. CONCLUSION: Distal risk indicators may have a stronger impact on ECC prevalence than do proximal risk indicators.. Approaches to control ECC may need to include political reforms

Impact of Protracted War Crisis on Dental Students: A Comparative Multicountry Cross-sectional Study

BACKGROUND: The impact of conflict and war crisis on dental students is poorly understood. Given the prolonged conflicts and political instability in the Arabic-speaking countries, it is crucial to investigate the effect of these conditions on dental students. This study aimed to assess the impact of protracted war on dental students by comparing the personal, university, and wider context challenges they face across war-affected and unaffected countries. METHODS: A cross-sectional study was conducted including a convenience sample of dental students from 13 universities in 12 Arabic-speaking countries. Respondents were those at entry and exit points of their undergraduate dental training. A self-administered paper questionnaire collected anonymized data on sociodemographics, and personal, university, and wider context challenges that students were facing. Multivariable Poisson regression analyses were carried out. RESULTS: The overall response rate was 64.8%. The mean age was 21.2 (standard deviation = 2.1) years, with 68% of participants being female. After adjusting for age and sex, dental students in Arabic-speaking countries affected by protracted war crisis were significantly more likely to report wider context challenges compared to their counterparts in unaffected countries (n = 2448; beta = 1.12; 95% confidence interval: 1.10-1.13; P < 0.001). DISCUSSION: Dental students in Arabic-speaking countries affected by protracted war crisis were more likely to suffer from wider context challenges such as difficulties in attendance due to the deterioration of security and lack of flexibility of teaching time to accommodate the different circumstances induced by the war crisis. Supporting dental students in areas affected by protracted war crises is needed and may include developing online dental education programs

Knowledge of dental academics about the COVID-19 pandemic: a multi-country online survey

Background: COVID-19 is a global pandemic affecting all aspects of life in all countries. We assessed COVID-19 knowledge and associated factors among dental academics in 26 countries. Methods: We invited dental academics to participate in a cross-sectional, multi-country, online survey from March to April 2020. The survey collected data on knowledge of COVID-19 regarding the mode of transmission, symptoms, diagnosis, treatment, protection, and dental treatment precautions as well as participants’ background variables. Multilevel linear models were used to assess the association between dental academics’ knowledge of COVID-19 and individual level (personal and professional) and country-level (number of COVID-19 cases/ million population) factors accounting for random variation among countries. Results: Two thousand forty-five academics participated in the survey (response rate 14.3%, with 54.7% female and 67% younger than 46 years of age). The mean (SD) knowledge percent score was 73.2 (11.2) %, and the score of knowledge of symptoms was significantly lower than the score of knowledge of diagnostic methods (53.1 and 85.4%, P &lt; 0.0001). Knowledge score was significantly higher among those living with a partner/spouse than among those living alone (regression coefficient (B) = 0.48); higher among those with PhD degrees than among those with Bachelor of Dental Science degrees (B = 0.48); higher among those seeing 21 to 30 patients daily than among those seeing no patients (B = 0.65); and higher among those from countries with a higher number of COVID-19 cases/million population (B = 0.0007). Conclusions: Dental academics had poorer knowledge of COVID-19 symptoms than of COVID-19 diagnostic methods. Living arrangements, academic degrees, patient load, and magnitude of the epidemic in the country were associated with COVD-19 knowledge among dental academics. Training of dental academics on COVID-19 can be designed using these findings to recruit those with the greatest need