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11.
Human bocavirus (HBoV) is predominantly found in the respiratory tract infections and in the stool of patients with gastroenteritis symptoms. However, data on the prevalence of HBoV genotypes in environmental samples are limited. Here we addressed the prevalence of HBoV in sewage collected from three different wastewater treatment plants in Egypt. HBoV-1, HBoV-2, and HBoV-3 were detected, whereas none of the samples were positive for HBoV-4. The median concentration of HBoV in influent samples was 8.5 × 103 GC/l for HBoV-1, 3.0 × 104 GC/l for HBoV-2, and 2.5 × 104 GC/l for HBoV-3. The concentration was reduced but not completely removed in the effluent samples. The median concentration in the outlet samples was 2.9 × 103 GC/l for HBoV-1, 4.1 × 103 GC/l for HBoV-2, and 2.1 × 103 GC/l for HBoV-3. Moreover, no seasonality pattern of HBoVs was found. The high incidence of HBoV in sewage samples provided an evidence of its circulation in the local population. Although the role of HBoV in respiratory or gastro-intestinal infections still remains to be fully elucidated, the risk of infection via contaminated water should be taken into consideration.  相似文献   
12.
In this study, several bio-source-fuels like fresh and waste vegetable oil and waste animal fat were tested at different injector pressures (120, 140, 190, 210 bar) in a direct-injection, naturally aspirated, single-cylinder diesel engine with a design injection pressure of 190 bar. Using 2k factorial analysis, the effect of injection pressure (Pi) and fuel type on three engine parameters, namely, combustion efficiency (etac), mass fuel consumption (mf), and engine speed (N) was examined. It was found that Pi and fuel type significantly affected both etac and mf while they had a slight effect on engine speed. Moreover, with diesel and biodiesels, the etac increased to a maximum at 190 bar but declined at the higher Pi value. In contrast, higher Pi had a favorable effect on etac over the whole Pi range with all the other more viscous fuels tested. In addition, the mass fuel consumption consistently decreased with an increase in Pi for all the fuels including the baseline diesel fuel, with which the engine consistently attained higher etac and higher rpm compared to all the other fuels tested.  相似文献   
13.
The ratio of organic mass (OM) to organic carbon (OC) in PM(2.5) aerosols at US national parks in the IMPROVE network was estimated experimentally from solvent extraction of sample filters and from the difference between PM(2.5) mass and chemical constituents other than OC (mass balance) in IMPROVE samples from 1988 to 2003. Archived IMPROVE filters from five IMPROVE sites were extracted with dichloromethane (DCM), acetone and water. The extract residues were weighed to determine OM and analyzed for OC by thermal optical reflectance (TOR). On average, successive extracts of DCM, acetone, and water contained 64%, 21%, and 15%, respectively, of the extractable OC, respectively. On average, the non-blank-corrected recovery of the OC initially measured in these samples by TOR was 115+/-42%. OM/OC ratios from the combined DCM and acetone extracts averaged 1.92 and ranged from 1.58 at Indian Gardens, AZ in the Grand Canyon to 2.58 at Mount Rainier, WA. The average OM/OC ratio determined by mass balance was 2.07 across the IMPROVE network. The sensitivity of this ratio to assumptions concerning sulfate neutralization, water uptake by hygroscopic species, soil mass, and nitrate volatilization were evaluated. These results suggest that the value of 1.4 for the OM/OC ratio commonly used for mass and light extinction reconstruction in IMPROVE is too low.  相似文献   
14.
The 2017 Gulf crisis is one of the most challenging episodes faced by Qatar since its independence in 1971, with major economic, social, and political impacts on the Arab Gulf nation. Its economic prognosis has been brought into doubt, the map of regional alliances has been redrawn, and any prospects of deeper regional integration have been dashed. This paper analyses the little-documented impact of the crisis on Qatar's humanitarian sector, which has unfolded as the small, gas-rich emirate has striven to become a major humanitarian donor. It concludes that while there have been disruptions to humanitarian operations and regional coordination, the Gulf crisis has triggered and in some cases accelerated already intended reforms across the Qatari humanitarian sector. In the long term, the reorganisation and adaptation implemented to weather the storm of the crisis may help Qatar to emerge from the crisis with a more sustainable and resilient humanitarian sector.  相似文献   
15.
This paper examines the siege of the Gaza Strip, a self-governing Palestinian territory, since 2007. Research on sieges tends to concentrate on the coping strategies of besieged communities, humanitarian issues associated with the impacts, humanitarian access, and the prioritisation of needs, with little or no attention paid to reconstruction. However, Gaza is unusual as a siege environment within which reconstruction has become a high priority in the aftermath of its three destructive wars with Israel. Following an overview of research on sieges in contemporary warfare and a brief contextualisation of Gaza, this paper examines why reconstruction outcomes have varied over time through the application of a theoretical framework that stipulates the importance of four key factors: time; needs; scarcity; and political context. Based on an analysis of these variables, Gaza was found to be a most-likely case for reconstruction under siege. Nonetheless, the large-scale reconstruction necessary to transform Gaza has not been actualised.  相似文献   
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