101 research outputs found

    Focal Mechanism Analyses of the 1993, 1995 Northern red Sea Sequences Activity

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    On August 3rd, 1993, a sequence of earthquakes began in the central part of the Gulf of Aqaba, northern Red Sea at the Aragonese Deep. The largest event (MD = 5.5) on August 3rd had an origin time of 12:42:43.22 GMT, a latitude of 28.628° N and longitude 34.644° E. This event was followed by more than 15000 events greater than 2 magnitude with some felt earthquakes. On the same spot, another sequence of earthquakes began late 1995. The largest event (MD = 5.9) on November 22 had an origin time of 04:15:12.30 GMT, a latitude of 28.8° N and longitude 34.7° E. This event was followed by more than 8000 aftershocks (1.5 D° N – 29.3° N and 34.6° E – 34.9° E. Focal mechanism were investigated by using data set obtained from the Seismic Network of the Seismic Studies Center, King Saud University, Riyadh, Saudi Arabia and the National Seismic Network at Institute of Astronomy and Geophysics Researches, King Abdulaziz City for Science and Technology. The data set included P-wave first motions of significant earthquake activity in this sequences mainly. A total of 67 events was selected for focal mechanism analysis. The P-wave data from the surrounding seismic networks were also utilized additionally. The structural picture revealed fi-om the focal mechanism solutions shows that the area in general characterized by strike-slip and dip-slip faulting. The mechanism of the first consistent with left-lateral strike-slip on N-NE trending faults of the Dead Sea Transform System. The second consistent with normal faults that generally trend E-W. The main objective of this work is to study the focal mechanism of the recent Northern Red Sea sequences of August 1993 and November 1995 and to associate these sequences with faulting types that were found before using different methods

    Contribution of 3-D electrical resistivity tomography for landmines detection

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    Landmines are a type of inexpensive weapons widely used in the pre-conflicted areas in many countries worldwide. The two main types are the metallic and nonmetallic (mostly plastic) landmines. They are most commonly investigated by magnetic, ground penetrating radar (GPR), and metal detector (MD) techniques. These geophysical techniques however have significant limitations in resolving the non-metallic landmines and wherever the host materials are conductive. In this work, the 3-D electric resistivity tomography (ERT) technique is evaluated as an alternative and/or confirmation detection system for both landmine types, which are buried in different soil conditions and at different depths. This can be achieved using the capacitive resistivity imaging system, which does not need direct contact with the ground surface. Synthetic models for each case have been introduced using metallic and non-metallic bodies buried in wet and dry environments. The inversion results using the L1 norm least-squares optimization method tend to produce robust blocky models of the landmine body. The dipole axial and the dipole equatorial arrays tend to have the most favorable geometry by applying dynamic capacitive electrode and they show significant signal strength for data sets with up to 5% noise. Increasing the burial depth relative to the electrode spacing as well as the noise percentage in the resistivity data is crucial in resolving the landmines at different environments. The landmine with dimension and burial depth of one electrode separation unit is over estimated while the spatial resolutions decrease as the burial depth and noise percentage increase

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

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    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

    Impact of diabetes continuing education on health care professionals’ attitudes towards diabetes care in a Yemeni city

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    Purpose: To evaluate the impact of a continuing education (CE) program on the attitudes of health care professionals (HCPs) towards diabetes care in Yemen.Methods: A pre- and post-intervention study was carried out in Mukalla City, Hadramout, Yemen and was offered to all physicians, pharmacists, and nurses registered in the Health Office in the Mukalla City. The HCPs were invited to attend a CE program. All participants filled out a questionnaire before the intervention (pre-test) that measured the attitudes of the participants towards diabetes. An interventional program was given in the form of a seminar, and participants were requested to complete the same questionnaire after the seminar.Results: A total of 73 HCPs attended the CE, including 19 pharmacists (26 %), 37 physicians (50.7 %), and 17 (23.3 %) nurses. The pre- and post-intervention changes in the questionnaire responses were significant only for attitude toward the values of blood glucose levels (p = 0.009) and attitude toward autonomy of diabetes patients (p = 0.023).Conclusion: HCPs in Mukalla City have positive attitudes toward diabetes. Physicians were more aware of the sequelae of diabetes than other healthcare professional groups with nurses showing the least understanding. Therefore, more emphasis should be placed upon designing education programs for diabetes specifically tailored for nurses and pharmacists.Keywords: Diabetes, Continuing education, Attitude, Health care professional

    210Po Log-normal distribution in human urines: Survey from Central Italy people

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    The death in London of the former secret service agent Alexander Livtinenko on 23 November 2006 generally attracted the attention of the public to the rather unknown radionuclide 210Po. This paper presents the results of a monitoring programme of 210Po background levels in the urines of noncontaminated people living in Central Italy (near the Republic of S. Marino). The relationship between age, sex, years of smoking, number of cigarettes per day, and 210Po concentration was also studied. The results indicated that the urinary 210Po concentration follows a surprisingly perfect Log-normal distribution. Log 210Po concentrations were positively correlated to age (p < 0.0001), number of daily smoked cigarettes (p = 0.006), and years of smoking (p = 0.021), and associated to sex (p = 0.019). Consequently, this study provides upper reference limits for each sub-group identified by significantly predictive variables

    Association between exposure to environmental tobacco smoke and biomarkers of oxidative stress among patients hospitalised with acute myocardial infarction

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    Objective To determine whether exposure to environmental tobacco smoke was associated with oxidative stress among patients hospitalised for acute myocardial infarction.&lt;p&gt;&lt;/p&gt; Design An existing cohort study of 1,261 patients hospitalised for acute myocardial infarction.&lt;p&gt;&lt;/p&gt; Setting Nine acute hospitals in Scotland.&lt;p&gt;&lt;/p&gt; Participants Sixty never smokers who had been exposed to environmental tobacco smoke (admission serum cotinine ≄3.0 ng/mL) were compared with 60 never smokers who had not (admission serum cotinine ≀0.1 ng/mL).&lt;p&gt;&lt;/p&gt; Intervention None.&lt;p&gt;&lt;/p&gt; Main outcome measures Three biomarkers of oxidative stress (protein carbonyl, malondialdehyde (MDA) and oxidised low-density lipoprotein (ox-LDL)) were measured on admission blood samples and adjusted for potential confounders.&lt;p&gt;&lt;/p&gt; Results After adjusting for baseline differences in age, sex and socioeconomic status, exposure to environmental tobacco smoke was associated with serum concentrations of both protein carbonyl (beta coefficient 7.96, 95% CI 0.76, 15.17, p = 0.031) and MDA (beta coefficient 10.57, 95% CI 4.32, 16.81, p = 0.001) but not ox-LDL (beta coefficient 2.14, 95% CI −8.94, 13.21, p = 0.703).&lt;p&gt;&lt;/p&gt; Conclusions Exposure to environmental tobacco smoke was associated with increased oxidative stress. Further studies are requires to explore the role of oxidative stress in the association between environmental tobacco smoke and myocardial infarction.&lt;p&gt;&lt;/p&gt

    Evaluation of metals that are potentially toxic to agricultural surface soils, using statistical analysis, in northwestern Saudi Arabia

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    © 2015, Springer-Verlag Berlin Heidelberg. Heavy metals in agricultural soils enter the food chain when taken up by plants. The main purpose of this work is to determine metal contamination in agricultural farms in northwestern Saudi Arabia. Fifty surface soil samples were collected from agricultural areas. The study focuses on the geochemical behavior of As, Cd, Co, Cr, Cu, Hg, Pb and Zn, and determines the enrichment factor and geoaccumulation index. Multivariate statistical analysis, including principle component analysis and cluster analysis, is also applied to the acquired data. The study shows considerable variation in the concentrations of the analyzed metals in the studied soil samples. This variation in concentration is attributed to the intensity of agricultural activities and, possibly, to nearby fossil fuel combustion activities, as well as to traffic flows from highways and local roads. Multivariate analysis suggests that As, Cd, Hg and Pb are associated with anthropogenic activities, whereas Co, Cr, Cu and Zn are mainly controlled by geogenic activities. Hg and Pb show the maximum concentration in the analyzed samples as compared to the background concentration

    Groin wound infection after vascular exposure ( GIVE ) multicentre cohort study

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    Surgical site infections (SSIs) of groin wounds are a common and potentially preventable cause of morbidity, mortality, and healthcare costs in vascular surgery. Our aim was to define the contemporaneous rate of groin SSIs, determine clinical sequelae, and identify risk factors for SSI. An international multicentre prospective observational cohort study of consecutive patients undergoing groin incision for femoral vessel access in vascular surgery was undertaken over 3 months, follow‐up was 90 days. The primary outcome was the incidence of groin wound SSI. 1337 groin incisions (1039 patients) from 37 centres were included. 115 groin incisions (8.6%) developed SSI, of which 62 (4.6%) were superficial. Patients who developed an SSI had a significantly longer length of hospital stay (6 versus 5 days, P = .005), a significantly higher rate of post‐operative acute kidney injury (19.6% versus 11.7%, P = .018), with no significant difference in 90‐day mortality. Female sex, Body mass index≄30 kg/m2, ischaemic heart disease, aqueous betadine skin preparation, bypass/patch use (vein, xenograft, or prosthetic), and increased operative time were independent predictors of SSI. Groin infections, which are clinically apparent to the treating vascular unit, are frequent and their development carries significant clinical sequelae. Risk factors include modifiable and non‐modifiable variables
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