1,104 research outputs found
Seasonal biodiversity and ecological studies on the epiphytic microalgae communities in polluted and unpolluted aquatic ecosystem at Assiut, Egypt
A qualitative and quantitative study on epiphytic microalgae was carried out seasonally from November 2015 to August 2016 to follow up their community structures on aquatic macrophytes related to some physico-chemical properties of two polluted and unpolluted water bodies at Assiut, Egypt. A total of 169 species related to 64 genera of epiphytic microalgae were recorded. The most dominant algal group was Bacillariophyceae (43.2%), followed by Chlorophyceae (34.91%), Cyanophyceae (20.71%) and Euglenophyceae (1.18%). The total number of epiphytic algae fluctuated between 11.1 × 104 ind.g-1 plant dry wt. on Phragmites australis in summer at Nazlet Abdellah (polluted site) and 10.02 × 107 ind.g-1 plant dry wt. on Myriophyllum spicatum in winter at El-Wasta (unpolluted site). Some epiphytic microalgae were dominant as Pseudanabaena limnetica, Calothrix braunii, Scenedesmus acutus, and Ulnaria ulna. Others were specific on certain macrophytes as Aphanocapsa thermalis and Ulothrix sp., which grow on Phragmites australis, while Synechocystis minuscula attached itself on Myriophyllum spicatum. Analysis of PERMANOVA showed that the most important factors that induced the variation in epiphytic microalgae were the temporal variation and host plant. Water temperature, pH, nitrate, chloride, phosphate and total dissolved salts were the highest abiotic factors correlated with the variation in composition of epiphytic microalgae
Nature and Disposition of the Garnet-Biotite Boundary at Balquhidder, Perthshire, Scotland
The metamorphic rocks at Balquhidder are polyphase deformed and polymetamorphosed with the D1 - D4 sequential development of structures and the M1 - M4 development of minerals generally corresponding to that expressed in nearby areas. Garnet is found throughout the area and the Barrovian garnet-isograd must have been at least 2Km above the present topography. There is no garnet-biotite boundary present. The incoming of garnet was controlled by the bulk rock composition so that garnetiferous and non-garnetiferous schists can occur in the same, or adjacent outcrops. Textural studies have shown that two phases of garnet growth occurred. The more prominent of these was during M2 when three different types were formed (G2A, G2B, G2C), two only lithologies of the Pitlochry Schist (G2A, G2C) and the other (G2B) only in the Ben Lui Schist. Growth of garnet was related to particular mineral reactions, non-instantaneous nucleation and reaction partitioning. This has been substantiated by the determination, using the electron microprobe of chlorite, muscovite, garnet, biotite, albite and hornblende compositions. Garnet-biotite and garnet-hornblende pairs permit temperatures of M2 metamorphism to be determined: 530 C - 482 C for type G2A (almandine), 423 - 410 C for type G2B (almandine) and 370 C for type G2C (spessartine-rich). The 530 C estimate for G2A is considered to represent climactic conditions and, when considered with a pressure estimate of 7Kb based on the biotite-muscovite-chlorite-quartz geobarometer, indicates a typical Barrovian heat flow of c. 27 C/Km and mid-amphibolite-facies conditions. On the basis of regional correlation of structures, the M2 metamorphism (and D1 - D2) is related to the pre-590Ma Grampian Orogeny and was followed by elevation of temperature to its peak during crustal thickening during D1 (Tay Nappe formation). A second phase of garnet growth took place post-D2 - pre-D4 (possibly post-D2 - pre-D3). Temperature of development of G2-4 (?G2-3) was 377 C for a spessartine-rich type, i. e. in the green schist facies. The elevation of temperature is related to the c. 500Ma event demonstrated elsewhere in the Highlands on the basis of isotopic studies and during which crustal thickening is postulated. Previous interpretations of the presence of an inverted garnet isograd are not substantiated by this investigation. The structural development does not permit inversion of M2 or M2-4 geotherms by tectonic activity, while the distribution of garnet throughout the area does not permit the presence of any isograd to be demonstrated. Rather the whole area is within the garnet zone. Two of the previous interpretations, which suggest an inverted zonal distribution, recognized neither the composition - nucleation - reaction partitioning controls nor the polyphase development of garnet. One sets out a position for a "garnet isograd" that corresponds to the prominent development of G2A and G2C garnets in particular flat-lying units of the Pitlochry Schist. The other sets out a position for a "garnet isograd" that corresponds to the prominent development of G2B and G2-4 garnets in particular units of the Ben Lui Schist. These interpretations are rejected on the basis of the detailed evidence set out here. D4 and post-D4 mineralogical expressions only result in minor modifications to the earlier formed features. D4 is correlated with the regionally expressed c. 460Ma period of uplift and post-D4 mineral growth was both prograde and retrograde. The deformation and metamorphic history in the Balquhidder area generally corresponds to, and may be representative of, Caledonian activity in at least considerable parts of the SW Highlands
Biochemical composition and antioxidant properties of some seaweeds from Red Sea coast, Egypt
The current study investigated the biochemical composition and antioxidant properties of four seaweeds: Laurencia sp. (Rhodophyta), Cystoseira myrica, Hydroclathrus clathratus and Padina pavonica (Ochrophyta). The highest amount of carbohydrates was (215.78 mg/g dry wt.) in Laurencia sp. and proteins content was maximum (50 mg/g dry wt.) in Laurencia sp. and Cystoseira myrica. The highest values of free amino acid content were recorded in the brown seaweed species Cystoseira myrica (4.01 mg/g dry wt.). The pressurized hot water extract of Cystoseira myrica has the highest total phenolic content (1.61 mg GAE/g dry wt.). Cystoseira myrica contained the highest amounts of flavonoids (3.35 mg/g dry wt.), ascorbic acid (9.07 mg/g dry wt.) and α-tocopherol (27.25±0.00 abs. at 520 nm/g dry wt.). Furthermore, the ethyl alcohol extract of Cystoseira myrica showed high antioxidant capacities (541.6 mg/g dry wt.) and achieved the most powerful reducing ability among all of the different extracts of algal species. Statistical evaluation by Spearman correlation between the TAC assay and the total phenolic contents was found to be significant, but the correlation was nonsignificant between FRAP assay and the total phenolic contents. The composition of elements of the studied seaweed species was also analyzed. The most significant macro-elements present in the studied seaweeds were K, Na and Ca, representing that the seaweeds are good sources of these elements. Since, these seaweeds are widespread in the Egyptian waters, their biochemical composition and antioxidant capacities made them promising candidates for industrial, nutritional and pharmaceutical applications.
DOI: http://dx.doi.org/10.5281/zenodo.147886
A SHALLOW NEURAL NETWORK MODEL FOR URBAN LAND COVER CLASSIFICATION USING VHR SATELLITE IMAGE FEATURES
Recently, image classification techniques using neural networks have received considerable attention in sustainable urban development, since their applications have an extreme effect on building distribution, infrastructural networks, and water resource management. In this research, a back-propagation shallow neural network model is presented for very high resolution satellite image classification in urban environments. Workflow procedures consider selecting and collecting data, preparing required study areas, extracting distinctive features, and applying the classification process. Visual interpretation is performed to identify observed land cover classes and detect distinctive features in the urban environment. Pre-processing techniques are implemented to present the used images in a more suited form for the classification techniques. A shallow neural network model (supported by MathWorks MATLAB environment) is successfully applied and results are evaluated. The proposed model is tested for classifying both WorldView-2 and WorldView-3 multispectral images with different spatial and spectral characteristics to check the model’s applicability to various kinds of satellite imagery and different study areas. Model outcomes are compared to two well-known classification methods; the Nearest Neighbour object-based method and the Maximum Likelihood pixel-based classifier, to validate and check the model stability. The overall accuracy achieved by the proposed model is 86.25% and 83.25%, while the nearest neighbour approach has obtained 84.50% and 82.75%, and the maximum likelihood classifier has accomplished 82.50% and 80.25% for study area 1 and study area 2 respectively. Obtained results indicate that the developed shallow neural network model achieves a promising accuracy for urban land cover classification in comparison with the standard techniques
Vibration Signature of Roller Bearing’s Faults
Centrifugal pumps are widely used in many industrial applications. Defective pumps cause higher rate of energy loss with related overall performance degradation. Mechanical components fail due to decrease in pump’s strength or an increase in the force acting on it. Rolling bearings are one of the major components of the centrifugal pumps. Bearings are critical mechanical components in industrial machines. Bearing failure is often attributed to be one of the major causes of breakdown. Early detection of undesired conditions during the operation of the centrifugal pump has become very important in order to avoid consequential damages. Early detection is also vital for increasing availability and reliability. Automated health monitoring can reduce the outage time and repair costs. Using vibration analysis technique to monitor and evaluate the health of the machines has become an important technique in this field. In this research, we studied the vibration signatures of healthy and faulty conditions of the bearings of a pumping system. The pumping system consists of centrifugal pump and electrical motor. The vibration signatures analyze the bearing status with respect to the normal operation. The paper shows how to identify if there is a problem in the outer race of the Bearing Pass Frequency Outer Race (BPFO)
Radioprotective and anti-diabetic effects of Costus speciosus and carnosine
Purpose: To evaluate the possible radioprotective effect of Costus speciosus and carnosine as natural antioxidants in order to control the hyperglycemia developed in male albino rats exposed to acute oxidative stress induced by gamma radiation.
Methods: Twenty-eight adult male albino rats were divided into four groups. The first group was taken as a control group, while the three other groups were exposed to Ɣ irradiation at a single 7.5 Gy dose. Furthermore, the rats in the second and third groups were i.p. injected with Costus speciosus root powder and carnosine, respectively. On the 3rd day, after irradiation, the serum levels of glucose, insulin, C peptide, copper, iron, calcium, total antioxidant capacity (TAC) and malondialdehyde (MDA) were measureded.
Results: The results revealed that exposure to Ɣ irradiation induced significant increases in serum glucose, iron, and malondialdehyde. However, the levels of serum calcium, copper, total antioxidant capacity and insulin significantly decreased (p < 0.05). A significant decrease was observed in Cpeptide in the exposed group, compared to control group. All the test parameters indicate improvement after treatment with Costus speciosus and carnosine (p < 0.05).
Conclusion: Costus speciosus and carnosine ameliorate the effect of gamma radiation, indicating their role as antidiabetic agents and radioprotectors; however, Costus speciosus was critically more efficient than carnosine.
Keywords: Costus speciosus, Carnosine, Diabetes, Insulin, Gamma radiation protectio
Long noncoding RNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1): A molecular predictor of poor survival in glioblastoma multiforme in Egyptian patients
Background: Long noncoding RNAs (lncRNAs) are a recently discovered class of transcribed RNA molecules with a length of more than 200 nucleotides. Recent studies have shown that lncRNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) could play an important role in carcinogenesis and cancer progression in several types of malignancies.Objective: As little is known about the role and clinical significance of lncRNA MALAT1 in glioblastoma multiform (GBM) patients in Egyptian population, this study aimed to investigate the expressions of lncRNA-MALAT1 in human GBM samples and to correlate these expressions with the available clinicopathological features including patient survival data.Subjects and methods: The relative expression of MALAT1 was determined in 37 human glioblastoma formalin-fixed paraffin embedded (FFPE) tissue samples and 10 FFPE non-neoplastic brain tissues using quantitative reverse transcription polymerase chain reaction (qRT-PCR) technology.Results: The current results revealed that lncRNA MALAT1 expression was down-regulated in all tumor specimens compared to normal tissues. A receiver operating characteristic (ROC) curve analysis showed high diagnostic performance; area under curve (AUC) =0.925 ± 0.038 (P <0.001), 95% CI= 0.850–1.00, with 94.6% sensitivity, and 72.7% specificity. Lower MALAT1 expression was associated with poor prognosis; higher frequency of recurrence (P < 0.044), lower overall survival (P <0.005), and shorter disease-free survival (P < 0.004).Conclusion: Taken together, we could postulate that MALAT1 might have a tumor-suppressive function in GBM in Egyptian population and this specific type of lncRNAs may be included in the lists of both potential prognostic biomarkers and the future therapeutic targets for glioblastomas
Enhancing the Performance of Power System under Abnormal Conditions Using Three Different FACTS Devices
In this paper, a comparison between Flexible Alternating Current Transmission System (FACTS) devices including Static Synchronous Compensator (STATCOM), Static Synchronous Series Compensator (SSSC) and Unified Power Flow Controller (UPFC) for providing a better adaptation to changing operating conditions and improving the usage of current systems. The power system using FACTS devices is presented under different conditions such as single phase fault and three phase fault. A digital simulation using Matlab/Simulink software package is carried out to demonstrate the better performance including the voltage and the current of the presented system using FACTS that located between buses B1 and B2 under different faults types. The results obtained investigate that the presented system gives better response with FACTS as compared to not using them under abnormal conditions besides, the UPFC gives better performance of power system under several faults as compared to STATCOM or SSSC as It can absorb reactive power in a manner which significantly reduced the fault current. It is demonstrated that UPFC can reduce the peak fault current at bus B1 to 63.85% of its value without using FACTS devices under line to ground fault and 79.18% under three line to ground fault whereas STATCOM and SSSC reduce it to (75.21, 94.35%) and (75.40, 94.68%), respectively
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