27 research outputs found

    DOES SILICON ALLEVIATE the INJURIES of NITROGEN DEFICIENCY and FENOXAPROP–P–ETHYL HERBICIDE in WHEAT (Triticum aestivum, L.)?

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    Si application alleviates influence of some abiotic stresses on crop plants. Meanwhile, scarce information is avaiable about the significance of Si for helping the plants to overcome the injuries of N deficiency and herbicides pressure. Thus, two–year 2–field experiments were carried out in wheat. Experiment I involved three Si concentrations (Si0ppm, Si250ppm and Si500ppm) and two N levels(N100% and N50%). Experiment II examined four combinations of fenoxaprop–p–ethyl and Si: fenoxaprop–p–ethyl+Si250ppm and fenoxaprop–p–ethyl+Si500ppm (each either in sequence or in tank mixture), fenoxaprop–p–ethyl alone, hand weeding and weedy check. Under N deficiency (N50%), Si500ppm increased plant height as compared to the control. No significant differences in SPAD values were detected amongst Si concentrations under each of the two tested N levels. Si can partially alleviate negative N deficiency effect on wheat yield, causing its increase to level obtained under normal N supply. Si has no effect on weed biomass when applied with fenoxaprop–p–ethyl either in sequence or in tank mixing. The most promising treatment for maximizing wheat grain yield was the application of 100 kg N ha–1 (N50%) x fenoxaprop–p–ethyl+Si250ppm in sequence", which also, in the same time, means reducing both cost of crop production and environment pollution

    TRA-954: SOLUTION MODEL FOR URBAN TRAFFIC CONGESTION: EGYPTIAN CASE STUDY

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    Traffic congestion is a major problem in many cities around the world resulting in massive delays, increased fuel wastage, environmental impact and other negative consequences affecting the daily life of each individual. From a transportation engineering point of view, making the correct decision to eliminate such congestion problems can be very difficult for decision-makers who carry the burden of analyzing large quantities of data which could be vague and conflicting in nature. Therefore, an effective and consistent system is required to simplify the decision-making process of the traffic congestion control. Traffic simulation could be that tool. The seriousness of traffic congestion in Egypt is the main motive for the study presented herein. The study aims at developing a model that sets guidelines on how to approach an urban congested traffic area, be able to tackle the problem and choose the effective engineering solution in terms of either geometry and/or structure. Sectors of El Nasr Road, Cairo with a total length of 2.4 km is chosen as a typical example of an urban area with traffic congestion hotspots. It serves as an excellent location to implement the traffic solution model on. The model is developed and implemented as follows: collection of traffic data, diagnosis of the congestion problems in terms of social, commercial, cultural, and behavioral aspects. The analysis of the data finger points out the flag areas by conducting total and peak traffic volume counts, simulation of the existing traffic conditions to get the delayed travel times of vehicles in that area. The analysis of the output would finally help decide whether such problem would be solved by geometric adjustments of the surface or the problem requires a multi-layered intersection

    SOWING DATE AND IRRIGATION EFFECTS ON PRODUCTIVITY AND WATER USE EFFICIENCY IN SUNFLOWER

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    Abiotic stresses represent a major impediment to crop productivity, especially in arid regions. Thus, over two years of 2014 and 2015, a field experiment was undertaken at El Nubaria region, Egypt to assess the productivity and water use efficiency (WUE) of sunflower as affected by planting dates (April 21, May 21, and June 21) and  irrigation levels (ET100%, ET85% and ET70%,). Results clarified that leaf chlorophyll a content was higher by sowing in May than in either April or June sowings, while leaf carotenoides of plant sown in May or June surpassed those sown in April. The minimal value of proline was obtained with sowing in May. Sowing in May increased plant height by 52.2 and 22.3 as well as LAI by 19.3 and 73.1% than sowing in April and June, respectively. The reductions in seed yield, oil yield and WUE amounted to 10.5 and 12.8, 13.7 and 18.3 as well as 11.8 and 9.8 % with April and June sowings, respectively, compared to May sowing. ET100% showed superiority over than ET85% and ET70% in improving sunflower yields and its attributes, but WUE did not affect. Sunflower sown in May and irrigated with ET100% gave the maximum values of seed yield and its attributes and WUE surpassing other interaction treatments. In June, WUE value increased under severe water deficit i.e. ET70% comparing to moderately water–stressed (ET85%) or well–watered conditions (ET100%)

    Comparative evaluation of INNO-LiPA HBV assay, direct DNA sequencing and subtractive PCR-RFLP for genotyping of clinical HBV isolates

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    Genotypes (A to H) of hepatitis B virus (HBV) influence liver disease progression and response to antiviral therapy in HBV-infected patients. Several methods have been developed for rapid genotyping of HBV strains. However, some of these methods may not be suitable for developing countries. The performance of INNO-LiPA HBV Genotyping assay (LiPA), direct DNA sequencing and subtractive PCR-RFLP of genotype-specific HBV genome regions were evaluated for accurately determining the HBV genotypes by analyzing sera (n = 80) samples from chronic HBV patients. Both, LiPA and DNA sequencing identified 63, 4 and 13 HBV strains as belonging to genotype D, genotype A and mixed genotype A and D, respectively. On the contrary, the PCR-RFLP-based method correctly identified all 4 genotype A but only 56 of 63 genotype D strains. Seven genotype D strains yielded indeterminate results. DNA sequence comparisons showed that a single nucleotide change in the target region generated an additional restriction site for Nla IV that compromised the accuracy of this method. Furthermore, all the mixed genotype A and D strains were identified only as genotype A strains. The data show that the PCR-RFLP-based method incorrectly identified some genotype D strains and failed to identify mixed genotype infections while LiPA and DNA sequencing yielded accurate results

    Molecular analysis of HBV genotypes and subgenotypes in the Central-East region of Tunisia

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    <p>Abstract</p> <p>Background</p> <p>In Tunisia, country of intermediate endemicity for Hepatitis B virus (HBV) infection, most molecular studies on the virus have been carried out in the North of the country and little is known about other regions. The aim of this study was to determine HBV genotype and subgenotypes in Central-East Tunisia. A total of 217 HBs antigen positive patients were enrolled and determination of genotype was investigated in 130 patients with detectable HBV DNA. HBV genotyping methods were: PCR-RFLP on the pre-S region, a PCR using type-specific primers in the S region (TSP-PCR) and partial sequencing in the pre-S region.</p> <p>Results</p> <p>Three genotypes (D, B and A) were detected by the PCR-RFLP method and two (D and A) with the TSP-PCR method, the concordance between the two methods was 93%. Sequencing and phylogenetic analysis of 32 strains, retrieved the same genotype (D and A) for samples with concordant results and genotype D for samples with discordant results. The sequences of discordant genotypes had a restriction site in the pre-S gene which led to erroneous result by the PCR-RFLP method. Thus, prevalence of genotype D and A was 96% and 4%, respectively. Phylogenetic analysis showed the predominance of two subgenotypes D1 (55%) and D7 (41%). Only one strain clustered with D3 subgenotype (3%).</p> <p>Conclusions</p> <p>Predominance of subgenotype D7 appears to occur in northern regions of Africa with transition to subgenotype D1 in the East of the continent. HBV genetic variability may lead to wrong results in rapid genotyping methods and sequence analysis is needed to clarify atypical results.</p

    WEED MANAGEMENT UNDER DIFFERENT PATTERNS OF SUNFLOWER-SOYBEAN INTERCROPPING

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    Two field experiments were conducted at the Experimental Farm of the National Research Centre at Shalakan, Kalubia Governorate, Egypt during the 2005 and 2006 seasons to study the effect of three weed management {hand hoeing twice, butralin+prometryn and unweeded check} as well as six intercropping patterns {two pure stand crops, besides intercropping sunflower: soybean {sun: soy} alternating ridges 1:1, 1:2, 2:1 as well as side: side}. Results showed that the lowest light intensity was recorded with sole soybean. Hoeing achieved the lowest dry weights of the grassy, broad-leaved and total weeds, but statistically leveled with those of butralin+prometryn in grassy and broad-leaved weeds. The lowest dry weight of grasses was recorded with 1:1 and 1:2 intercropping patterns. Hoeing was the best treatment for promoting sunflower and soybean seed yields/fed. Among the intercropping systems, the pattern of side: side appeared the highest significant sunflower seed yield than the rest of other intercropping ones and could recover maximum of its sole sunflower yield (81.3 %). The highest LER values, i.e. 1.376 and 1.198 recorded when sunflower and soybean intercropped in side: side and 1:2, respectively. The Aggressivity values indicated that sunflower component was the dominated, while soybean was the dominant one

    Investigation of a 5 kJ conical Z-pinch discharge

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    A conical 5 kJ Z-pinch experiment with 35 Οs discharge time was constructed and operated. Preliminary results showed that the total circuit parameters are 287 nH inductance and 13 mΊ total resistance. The cone plasma inductance has its maximum value at the pinch. It has been determined that the pinching time is inversely proportional to the deposited energy. Moreover, a calculated delay time of about 2.1 Οs is required for the pinch to occur and the calculated sheath velocity ranges between 1 and 11.5 cm/Οs. Erosion of the pin electrode could potentially explain the difference between the mass of helium gas inside the cone and the calculated swept mass. The main product of the ionization process is a singly-ionized helium atom
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