293 research outputs found
Nematodes associated with soybean (Glycine max) in upper Egypt
Dix-sept espèces de nématodes phytoparasites ont été récoltées dans les champs de soja des Gouvernorats de Menia, Assiut et Sohag, en Haute Egypte. Les espèces #Helicotylenchus pseudorobustus, Longidorus pisi, Pratylenchoides ritteri, P. variabilis, rotylenchulus parvus et #Tylenchorhynchus annulatus sont signalées pour la première fois en Egypte. #Merlinius brevidens est rencontré avec une fréquence relativement élevée tandis que #Pratylenchus zeae est présent en populations assez denses. #Meloidogyne javanica, M. incognita, Pratylenchus zeae, H. pseudorobustus, R. parvus et #Xiphinema sp. pourraient également avoir une grande importance dans les champs de soja de Haute Egypte. Les populations de #Meloidogyne javanica et #M. incognita sont plus élevées dans les sols sableux que dans les sols sablo-argileux ou argileux. #Pratylenchus zeae et #M. brevidens sont présents en populations élevées dans les trois types de sol, et plus particulièrement dans les sols sableux. Les populations de #H. pseudorobustus sont relativement élevées dans les sols argileux, tandis que pour #R. parvus les sols sablo-argileux sont plus favorables. (Résumé d'auteur
Testing the WEAP Hydrologic Model for Awash Basin, Ethiopia “Soil Moisture Module with Watershed Demand Approach”
The research is financed by the Egyptian Government through the Nile Sector bilateral cooperation project Abstract Currently, there are several hydrological simulation models in use worldwide. Prior to adoption of a model to a specific basin, its feasibility and practicality should be tested. This study highlights on the application of Water Evaluation and Planning system (WEAP) model for hydrologic simulation of Awash river basin in Ethiopia. A monthly time step hydrologic model was developed using the soil moisture rainfall-runoff method incorporated in WEAP with an aim to check the suitability of the model for Awash river basin. For this purpose five selected flow gauge stations located at the upper, middle and lower Awash basin were used as control stations. The model is configured taking into account the effects of development and hence the water abstractions, storage, loss rate, etc. are estimated using the data provided through various kinds of research and survey in Ethiopia. Standard methods are also used to prepare the hydro-metrological and landuse input data for each sub-catchment. Based on data availability, the time period 1986-2005 was selected for the hydrologic simulation. The observed data were split for calibration (1986–1995) and validation (1996–2005) purposes. Initially, the model was set up using the default model parameters. Then, manual calibration is performed to reproduce the observed streamflow. The model-simulated values are compared with those obtained from observations using standard statistical tests on monthly and monthly average basis. From the performance test results, it is observed that the coefficient of determination (R2) and the Index of Agreement (IA) show a good fit. Furthermore, the Nash-Sutcliffe Efficiency (NSE) and the Percent Bias (PBIAS) calibration and validation results show good performance for Upper Awash stations and satisfactory results for the middle and lower Awash control stations. As a conclusion, the main modelling constraints were discussed and possible solutions were also suggested in order to improve the performance of water resources simulation models for the Awash basin. Keywords: Awash Basin, Hydrologic Simulation, Calibration, Validation, Model Performance, WEAP DOI: 10.7176/CER/12-3-07 Publication date:March 31st 202
Planning for Environmental Water Allocations: Hydrology - Based Assessment in the Awash River Basin, Ethiopia
The research is financed by the Egyptian Government through the Nile Sector bilateral cooperation project Abstract With expanding water demand due to rapid socio-economic growth and shrinking supplies due to pollution and climate change impact, there is an increasing strain on the water resources of the Awash river basin. Furthermore, flow alterations due to the existing and the ongoing water resources infrastructure projects may adversely impact the natural life cycle of aquatic ecosystems in the river basin. In order to manage these consequences, compensation releases or allocation of environmental flows may be mandatory and calls for the establishment of environmental flows framework in Ethiopia. In this study, the environmental flows at selected five existing and proposed dam sites in the Awash river basin were investigated using six worldwide used hydrology-based methods, viz.: Desktop Reserve Model (DRM), Global Environmental Flow Calculator (GEFC), Tennant, Tessman, 7Q10 and Q95. The environmental flow volumes from the six methods were compared on mean annual, monthly average and monthly basis and it is found that the predictions from the DRM and GEFC are more reliable than the others. Comparative results indicate that minimum annual average flow rates of 4.4 m3/s (15 % of Mean Annual Flow (MAF)), 10.5 m3/s (19 % of MAF), 16.4 m3/s (22 % of MAF), 2.5 m3/s (17 % of MAF) and 24.2 m3/s (26 % of MAF) are required at the immediate downstream reaches of Melka kuntre, Koka, Awash Compensation, Kesem and Tendaho dams respectively. Accordingly, the annual average environmental flow throughout the basin varies from 15-26 % of the natural MAF. Although preliminary, being the first attempt in the Awash river basin, this study is expected to stimulate dialogue among experts and decision makers in Ethiopia. Keywords: EFR, EFA, Tennant, Tessman, Q95, 7Q10, DRM, GEFC Software, Awash DOI: 10.7176/JEES/9-11-08 Publication date: November 30th 201
The Biomechanical Effect of Different Denture Base Materials on the Articular Disc in Complete Denture Wearers: A Finite Element Analysis
AIM: The objective of the present study was to evaluate the effect of different denture base materials on the stress distribution in TMJ articular disc (AD) in complete denture wearers.MATERIAL AND METHODS: Two three dimensional Finite Element (FEA) models of an individual temporomandibular joint (TMJ) were built on the basis CT scan. The FEA model consisted of four parts: the condyle, the articular disc, the denture base, and the articular eminence skull. Acrylic resin and chrome-cobalt denture base materials were studied. Static loading of 300N was vertically applied to the central fossa of the mandibular second premolar. Stress and strain were calculated to characterize the stress/strain patterns in the disc.RESULTS: The maximum tensile stresses were observed in the anterior and posterior bands of (AD) on load application with the two denture base materials. The superior boundaries of the glenoid fossa showed lower stress than those on the inferior boundaries facing the condyle.CONCLUSIONS: Within the limitations of the present study it may be concluded that: The denture base material may a have an effect in stress-strain pattern in TMJ articular disc. The stiffer denture base material, the better the distribution of the load to the underling mandibular supporting structures & reducing stresses induced in the articular disc
Nucleophilic Addition of Reactive Dyes on Amidoximated Acrylic Fabrics
Seven reactive dyes judiciously selected based on chemical structures and fixation mechanisms were applied at 2% owf of shade on amidoximated acrylic fabrics. Amidoximated acrylic fabric has been obtained by a viable amidoximation process. The dyeability of these fabrics was evaluated with respect to the dye exhaustion, fixation, and colour strength under different conditions of temperature and dyeing time. Nucleophilic addition type reactive dyes show higher colour data compared to nucleophilic substitution ones. FTIR studies further implicate the binding of reactive dyes on these fabrics. A tentative mechanism is proposed to rationalize the high fixation yield obtained using nucleophilic addition type reactive dyes. Also, the levelling and fastness properties were evaluated for all dyes used. Excellent to good fastness and levelling properties were obtained for all samples irrespective of the dye used. The result of investigation offers a new method for a viable reactive dyeing of amidoximated acrylic fabrics
Partial Purification and Characterization of Two Endo-Č•-1, 4-glucanase from Trichoderma sp. (Shmosa tri)
Abstract: Two endoglucanases (EC 3.2.1.4) from Trichoderma sp. (shmosaTri) FJ937359 were purified to homogeneity using ammonium sulfate precipitation and gel filtration. Purity was confirmed by SDS/PAGE. Enzymatic properties and molecular weights were determined. Molecular weights of CMCase I and II were 58 and 34 KDa, respectively. The effect of temperature on the 2 endoglucanase activity was studied and results showed that optimum activity obtained at 50°C for both CMCase I and II. The enzymes withstand 60 min at 50ºC without loss of enzymatic activity. CMCase I and II retained 14.0 and 26.5 % of their original activities at 70°C after 90 min. The optimum pH for CMCase I and II was 5.0. Results also show that CMCase I was active at room temperature after 24 hrs over a broad pH range (3.0-9.0) while CMCase II was relatively stable in pH range (4.0-6.0). Among different kinds of substrates, both enzymes showed a high preference for carboxymethyl cellulose while both CMCase I and II did not show any hydrolytic activity against chitin, starch and cellobiose. On the other hand both CMCase I and II have relatively low hydrolytic activity towards ȕ glucan and xylan. All metallic ions used as well as EDTA and SDS at a concentration of 20 ug/ml of reaction mixture have an inhibitory effect on both CMCase I and II
Bone Height Changes of the Mandibular Edentulous Ridge in Screw Retained Versus Telescopic Restorations for Completely Edentulous Patients
AIM: This study was established to evaluate the amount of bone height changes in the posterior mandibular area of edentulous patients receiving screw-retained prostheses versus removable telescopic implant overdentures.MATERIAL AND METHODS: Every patient received four inter-foraminal implants regarding the mandibular arch and four anterior implants for the maxillary arch, computer guided surgical guides were planned for the insertion of the implants accurately with a flapless technique. Panoramic radiographs were made immediately, six months and twelve months after the prostheses` use proportional area and vertical measurements were applied to determine changes in the bone height of the posterior mandibular edentulous area.RESULTS: After twelve months, a statistically non-significant amount of bone resorption was reported for both groups.CONCLUSION: Up to the limitations of this study both treatment options the screw retained and telescopic overdenture can be used for rehabilitation of completely edentulous patients. These cases must be followed for a longer period to have a definite answer regarding their efficiency in the long run
In Vivo Visualization of Hair Follicles by Ultrasound Biomicroscopy in Alopecia Areata and its Correlation with Histopathology
Ultrasound biomicroscopy (UBM) is a non-invasive imaging technique used in examination of several skin diseases but never in imaging hair and scalp diseases. Main objective of this investigation was assessment of the efficacy of UBM for in vivo visualization of hair follicles in cases of alopecia areata (AA) and correlation of findings with histopathological findings. This study included 30 patients with AA. Two areas, one with AA and a control area, were marked, examined by UBM and then biopsied for histopathological examination. In patients with alopecia totalis (AT) or universalis (AU) only an AA area was examined. Non-echogenic conical shadows reaching the epidermal entrance echo (probably corresponding to the hair follicles) were seen and were wider and fewer in number in areas of AA than in normal control areas. No significant difference was found regarding number and width of hair follicles between UBM and histopathological examination. However, a significant increase in length of follicles in histopathology was detected, indicating that the UBM image was probably unable to reach the deepest part of the follicle. Main limitation of the study is small number of cases. No significant difference was found between UBM and histological measurements of hair follicle number and width in patients with AA, making UBM a useful tool for in vivo visualization of hair follicles. </p
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