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- الأعداد السابقة
- الأعداد السابقة
QScience Connect - الأعداد السابقة
المجلد 2014, العدد 1
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Automatic seizure detection based on Teager Energy Cepstrum and pattern recognition neural networks
المؤلفون: Chandrakar KamathAbout 1–3% of the world population suffers from epilepsy. A long term inpatient/ambulatory electroencephalogram (EEG), lasting from a few hours to several days, which definitely contains hallmarks of epilepsy, is required clinically to diagnose, monitor and localize the epileptogenic zone. The traditional method relies on well-trained neurophysiologists who visually inspect the entire lengthy EEG signals, which is tedious and time-consuming. Therefore, many automated epileptic detection systems have been developed and such systems significantly reduce the time taken to review off-line the long-term EEG recordings and facilitate the neurologist to diagnose and treat more patients in a given time. There are not many studies that have explored, to a sufficient depth, the features used in other domains of signal processing, for example, the Teager energy cepstrum (TECEP), attempted use in seizure detection. Epileptic seizures are abnormal sudden discharges in the brain with signatures manifesting in the EEG recordings by frequency changes and increased amplitudes. These changes, in this work, are captured through static and dynamic features derived from TECEP. We compared the performance of the baseline TECEP and its two composite vectors with those of the traditional cepstrum (CEP) and its corresponding two composite vectors, in EEG epileptic seizure detection. The first composite vector includes velocity cepstral coefficients and the second includes velocity, as well as, acceleration cepstral coefficients. The comparison is tried on eight different classification problems which encompass all the possible discriminations in the medical field related to epilepsy, using pattern recognition neural network (PRNN). In this case, it is found that the overall performance of both the Teager energy composite vectors excels those of traditional cepstral composite vectors. The static and dynamic features derived from TECEP outperform those derived from CEP, suggesting their suitability in epilepsy seizure detection.
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Characterisation of thermal diffusivity and tensile properties of ultrasonically washed woven fabrics
المؤلفون: Muhammet UzunLaundering of textile garments is taken for granted worldwide, employing conventional washing machines to provide the physical effort exerted to remove dirt and debris from garments. In this study, the conventional washing technique and the advanced ultrasonic washing technique were analysed and compared by using several different types of fabrics. The thermal diffusivity, tensile strength and the breaking extension properties of the fabrics were tested and analysed to determine the laundering effects on the selected fabric properties. Both the conventional and the ultrasonic washed fabrics under dry and wet state were directly analysed and compared. It was observed that, the dry state of the fabrics reflected superior thermal diffusivity values in comparison to the wet state of the fabrics. The tensile strength and breaking extension of the washed fabrics were strongly affected by both washing processes. There is a significant decrease in their strength and breaking extension properties when the fabrics were washed.
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In vitro effect of the adding of an exogenous enzyme blend (Natuzyme®) on rumen microbial fermentation and methane production of diets containing different NDF concentrations
المؤلفون: A. Faramarzi-Garmroodi, M. Danesh Mesgaran, E. Parand and A.R. VakiliThe objective of the present study was to evaluate the effect of an exogenous enzyme blend (Natuzyme®) on the fermentation responses of diets differing in neutral detergent fiber (NDF) concentrations, using a proposed gas production technique. Diets contained different ratios of alfalfa hay to wheat straw, to provide different NDF concentration, such as 320 (D1), 340 (D2) and 360 (D3) g/kg dry matter (DM). Two hundred fifty mg of milled and dried experimental diets in three runs and four replicates were weighed into a 125-ml serum bottle for an in vitro gas production trial. A solution of Natuzyme® was added 12 hours prior to the commencement of the incubation (96 h), to make a treatment of 1.68 (g/kg DM). Serum bottles containing substrates without enzyme were considered as the control. Gas production parameters at 96 h incubation were estimated and half time of gas production (t1/2) was calculated. Another gas test was run according to t1/2. All the incubations for each treatment were terminated at t1/2, then gas and methane volumes recorded. Apparent dry matter degradability (ADMD) was assessed by centrifugation and ‘ml methane per mg dry matter apparently degraded’ was calculated. Results showed that level of alfalfa hay incorporation and elevation of NDF concentration in the diets significantly increased the fractional constant rate. Enzyme supplementation significantly increased the ADMD of the diets at t1/2, whereas gas production and produced methane per mg of DM at t1/2 (MD) of the experimental diets, was decreased at t1/2. Increasing the NDF content of the diet showed a significant contribution in altering the fermentation parameters at t1/2. Enzyme addition is an appropriate way to control the methane emission and to improve the dry matter degradability in the ruminant gut.
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Developing an agro-climatic zoning model to determine potential growing areas for Camelina sativa in Argentina
المؤلفون: SL Falasca, MC del Fresno and C WaldmanThe purpose of this paper was the development of an agro-climatic zoning model to determine potential growing areas for Camelina sativa in Argentina.
Camelina (Camelina sativa L.) is a promising and sustainable alternative energy crop that belongs to the Brassicaceae (mustard) family. Camelina sativa oil contains around 40% fatty acids, of which only a small percentage are saturated. Camelina sativa derived biokerosene used in aviation has shown 84% reduction in greenhouse gas emissions during its life cycle, compared to petroleum kerosene. It has the potential of becoming the renewable fuel of choice for air navigation in the future.
Agro-climatology is a valuable tool in the identification of agro-climates with favorable conditions for the introduction of new crops. Agro-climatic zoning permits identifying areas with different potential yields, as per their environmental conditions. It was necessary to evaluate the requirements, limits and bio-meteorological tolerance and conditions for these species, taking into account the climatological characteristics of native areas and regions for their successful cultivation around the world.
In order to define this crop's agroclimatic aptitude in Argentina, climatic data was analyzed from meteorological stations, corresponding to the period 1981-2010.
Finally, Camelina's potential growing areas were obtained with 5 differentiated suitability classes.
Based on international bibliography, the authors outlined an agro-climatic zoning model to determine potential growing areas in Argentina for Camelina sativa. This model may be applied to any part of the world, using the agroclimatic limits presented in this paper. This is an innovative work, made by the implementation of a Geographic Information System that can be updated by the further incorporation of complementary information, with the consequent improvement of the original database.
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Effect of green marketing on consumer purchase behavior
المؤلفون: Narges Delafrooz, Mohammad Taleghani and Bahareh NouriIn recent years, concern about the environment has been highlighted in many areas of life. Our limited resources are damaged, the future of human life disturbs this planet, thus leaders and thinkers have to create a solution. The influence of green marketing tools have been analysed in this study, namely the eco-label, eco-brand and environmental advertisement. The sampling used was available cluster sampling. Tehran city is divided into four parts, North, South, East and West. The western and northern areas of the city were selected and we distributed our questionnaire. The sample size was 384 people. Formulae and data was analysed using the Spearman correlation test and multiple regression analysis. The results show that environmental advertisement had the most significant effect on consumer purchasing behavior and eco-brand had the least effect.
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So, can teaching grammar work?
المؤلفون: Dina El-DakhsTeaching grammar has been a major area of debate and controversy in language teaching and second language acquisition for some time. Harsh criticism of traditional grammar teaching has continued over the last few decades, which has resulted in great confusion and lack of confidence among language teachers. This paper aims to encourage second language (L2) teachers and second language acquisition (SLA) researchers to reconsider the role of grammar instruction, through examining an alternative approach to grammar teaching, known as “form-focused instruction” (FFI), that reconciles with communicative language teaching (CLT). To this end, the paper reviews a number of studies in favor and against the direct teaching of grammar, and presents a brief discussion of four FFI options; namely, structured input, explicit instruction, production practice and negative feedback. Finally, the paper shows that grammar teaching is necessary to help students possess greater command of the target language. However, more input from L2 teachers and SLA researchers is needed to define the most effective FFI instructional options and strategies.
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An efficient algorithm on time-fractional partial differential equations with variable coefficients
المؤلفون: Jamshad Ahmad and Syed Tauseef Mohyud-DinIn this paper, a fractional complex transform (FCT) is used to convert the given fractional partial differential equations (FPDEs) into corresponding partial differential equations (PDEs), and subsequently reduced differential transform method (RDTM) is applied on the transformed PDEs. The results obtained are re-stated by making use of inverse transformation that yields in terms of original variables. It is observed that the proposed algorithm is highly efficient and appropriate for solving time fractional PDEs arising in mathematical physics, hence can be extended to other diverse problems.
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New application perspective for tetrahedral amorphous carbon coatings
المؤلفون: Stéphane NeuvillePresently various carbon-based materials are used to achieve different surface functions and coatings for anti-corrosion and electrochemical application. These are in the form of homogeneous composite materials and chemically modified polymers, with many patent pending in this field. However, association of performing anticorrosion, adherence crosslinking and hydrophobic solutions with other surface functions are more often required, including additional simultaneous tribologic, antiwear, electrochemical, optical and optoelectronic properties. Among the wide range of diamond-like and related coating materials, tetrahedral amorphous carbon (ta-C), combines many interesting, simultaneous and superior material properties compared with first generation hard carbon coatings. Especially when ta-C can be modified and adapted for its properties to a specific application by doping with multilayer and gradient configuration, thus offering many new and interesting perspectives of application. We review and discuss common coatings, by comparison and deduction. The corresponding updated and recently developed fundamentals are also considered to show the potential for better performing and up-scaled anti-corrosion and electrochemical solutions.
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Heat wave hazard modelling: Qatar case study
Heat waves are considered to be the major cause of environmental and weather-related fatalities. Heat waves also have a severe impact on people with chronic cardiac and respiratory diseases, such as asthma. With climate change and global warming processes taking place, general global climatic models predict that heat wave events will increase in frequency, duration, and intensity. Therefore, heat wave modelling has attracted considerable attention from scientists and decision-makers alike. Yet it remains challenging, complex, and an imperative problem. This complexity is introduced mainly by land surface and atmospheric spatial variability, such as land use and air pollution concentration.
This study addresses this spatial complexity by using remotely sensed thermal data in the form of Land Surface Temperature (LST) images, along with meteorological data to model heat waves in Qatar. Multi-criteria/multi-parameters/multi-layer analysis is carried out using Geographic Information System (GIS) by combining many complex parameters that influence or determine heat waves in the region. Gumble statistical frequency analysis is carried out on time series data to predict heat wave events.
Results from the model show that a high portion of the population's vulnerable age groups are likely to be severely affected by future heat wave events in Qatar- based on a five year return period. The analysis revealed that at least 87% of children aged 4 or under would be exposed to a very high intensity level of heat wave events, while more than 86% of elderly people, over 65 years of age, would be exposed to the same intensity level of hazard.
The study proves that thermal satellite imaging improves heat wave hazard modelling, as it addresses the complex spatial variability of land surface. The developed model is applicable at a local, as well as regional, scale, making an original contribution to heat wave modelling.
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On a recurrence relation
المؤلفون: Reza Mostafaei and Narges RastegarIn this paper, we investigate the nature of the solutions to the following difference equation:
where the initial values , parameters α, β, B, C are positive and k ∈ {1,2,3,…} is fixed.We study the boundedness nature and global behavior of its solutions. Also, we investigate the analysis of the semi-cycles under special conditions.
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Solvent-free synthesis, spectral studies, antimicrobial activities of some (E)-N-(substituted benzylidene)-9-ethyl-9H-carbazole-3-amine derivatives
المؤلفون: P. Mayavel, K. Thirumurthy, S. Dineshkumar and G. ThirunarayananBackground: This study aims to synthesis a series of (E)-N-(substituted benzylidene)-9-ethyl-9H-carbazole-3-amines, using solvent-free fly-ash:perchloric acid catalyst under microwave irradiation. To then characterize them using analytical, physical and spectroscopic data. Methods: Solvent-free microwave assisted (E)imines were adopted for the synthesis of (E)-N-(substituted benzylidene)-9-ethyl-9H-carbazole-3-amine, using fly-ash:perchloric acid as a catalyst. They were characterized by IR, NMR and mass spectroscopic data. The IR and NMR spectral data was correlated with substituent constants, F and R parameters using Hammett equation to study the effect of the substituents. Results: The yield of the synthesized imines were more than 75%. The spectral data of these (E)-N-(substituted benzylidene)-9-ethyl-9H-carbazole-3-amines had been correlated using single and multi-regression analysis. These gave a satisfactory or fair degree of correlation, with some parameters. Conclusion: Easy handling, non-hazardous and an environmentally safe method had been adopted for the synthesis of (E)-imines, using fly-ash:perchloric acid as catalyst, with better yields. Some of the Hammett spectral correlations were found to be satisfactory with the observed spectroscopic data.
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Cyproheptadine for central hypertension?
المؤلفون: Guido Filler, Lara Hart, April Chan, Elizabeth Cairney and Asuri N PrasadBackground: Approximately one-fifth of paediatric intracranial tumors result in hypertension. The condition is difficult to treat in this population, particularly if it is refractory, since there is little guidance on patient management beyond first-line therapy with IV labetalol. Methods: A 20-month-old patient was hospitalized with cerebral herniation-induced loss of consciousness and a posterior fossa mass was found. Although several first-line treatments including IV labetalol, furosemide, amlodipine, clonidine, and atenolol were administered, the patient's hypertension persisted. With few options left, positive findings from previously published case reports led the team to administer cyproheptadine. Results: Cyproheptadine resulted in improved blood pressure and allowed for a dose reduction in other antihypertensives, but elevated liver transaminases and suspected hepatotoxicity several weeks later resulted in the discontinuation of this treatment. Conclusions: Despite the safety concerns associated with using cyproheptadine to treat paediatric central hypertension, this treatment holds promise for persistent refractory hypertension as a last-line agent when all other treatment options are exhausted. Clinical use of this agent should be investigated in future studies, under careful supervision.
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Studying the impact of presence of point mutation, insertion mutation and additional chromosomal abnormalities in chronic myeloid leukemia patients treated with imatinib mesylate in the State of Qatar
المؤلفون: Nader I Al-Dewik, Andrew P Jewell, Mohammed A Yassin, Hanadi R El-Ayoubi and Hisham M MorsiBackground: Imatinib is failing as a first line treatment in more than 40% of chronic myeloid leukemia (CML) patients in Qatar. We thus investigated ABL1 kinase domain mutations and additional chromosomal abnormalities (ACAs) as underlying mechanisms to explain this high rate of treatment failure. Methods: Between November 2006 and December 2011, all CML patients in Qatar were studied for BCR-ABL1 kinase domain mutations and ACAs. Total RNA was extracted and cDNA was produced via reverse transcriptase polymerase chain reaction (RT-PCR). PCR was used with special precautions to avoid amplification of wild type ABL1; the ABL1 kinase domain was then screened for mutations by direct DNA sequencing technology to detect the emergence of mutant clone.
Cytogenetic analysis of bone marrow (BM) metaphases and fluorescence in situ hybridization (FISH) of peripheral blood (PB) and BM interphases were performed according to standard protocols. European Leukemia Net (ELN) response criteria were employed to identify the failing cases. Results: 26 out of 33 CML patients were eligible for the study, 22 CP and 4 AP. 14 failed Imatinib treatment, 2 had BCR-ABL1 kinase domain mutations; one patient had the G1739A mutation which leads to the exchange of glutamic acid at position 459 to lysine (E459K) (rs1064156) in the c-terminal loop while the other patient had a unique insertion of three nucleotides (AAG) at position 1432 which adds an amino acid Lysine to position 356 of the catalytic domain and a complex karyotyping at diagnosis, 6 had additional chromosomal abnormalities as an underlying mechanism of resistance, 4 patients had no identifiable cause of resistance and 2 patients were intolerant to treatment. There was a significant difference in median overall survival between patients with Ph chromosome only and patients with ACAs. Conclusions: In this study as we continued observing CML patients for nearly 5 years, the Imatinib failure reached as high as 54%. The resistance rate observed in Qatar is still higher than that reported by the IRIS study which is as high as 35%. In our cohort of CML patients, point mutation and unique tri-nucleotide insertions were identified. However, these mutations could explain only 14% of treatment failure. Additional chromosomal abnormalities were the most common cause of Imatinib failure in our patients' cohort and were documented in 50% of cases. 14% of patients stopped IM due to intolerance; and the mechanisms of resistance remained unknown in 28% of patients. Other causes such as patients' adherence to Imatitinb is being prospectively investigated.
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Endogenous knowledge and human disturbance impact on abundance of two underutilized wild edible tree species in southern Benin
This study assessed endogenous knowledge and impact of human disturbance on the abundance of two underutilized wild fruit tree species: Drypetes floribunda (Müll. Arg.) Hutch. (Euphorbiaceae) and Mimusops andongensis Hiern. (Sapotaceae) in the Lama Forest Reserve (LFR) in southern Benin. A survey was conducted with 145 randomly selected people amongst the surrounding communities of LFR in order to assess the endogenous knowledge of the species. One hundred square plots were established in the forest for characterizing species abundance in different habitats according to human disturbance degree. Results indicated that this species has multiple uses and either local knowledge on their uses or their organ plant uses depend on social factors. A densities assessment suggests a negative effect of human disturbance on the abundance of both species. Results support the need to envisage conservation and sustainable use strategies as perspective policies.
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A stability analysis of a self-gravitating optically thick magnetized quantum plasma including the effects of black body radiation
المؤلفون: V. Shrivastava, A.K. Patidar and R.K. PensiaWe have discussed the effect of black body radiation on self-gravitational instability of infinite homogeneous, optically thick quantum plasma carrying a uniform magnetic field. With the help of relevant linearized perturbation quantum magneto-hydrodynamic equations of the problem, using normal mode technique, a general dispersion relation is obtained with black body radiation, quantum correction and magnetic field. Discussed when propagation vectors are longitudinal and transverse to the magnetic field, separately. The new Jeans condition of instability due to quantum correction, magnetic field and black body radiation is discussed. We find that in transverse mode of propagation the condition of Jeans instability of gaseous plasma is modified by quantum correction, magnetic field and black body radiation. In the case of longitudinal mode, it is unaffected by a magnetic field, as this mode provides the Alfven mode separately with the gravitational mode. From the curves we found that the effects of quantum correction, black body radiation and magnetic field have a stabilizing influence.
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Removal of mercury in fixed-bed continuous upflow reactors by mercury-resistant bacteria and effect of sodium chloride on their performance
المؤلفون: Jaysankar De, Johannes Leonhäuser and Lilit VardanyanUrgent need to reduce the amount of toxic mercury compounds in the wastewater of industries and subsequent reuse of metal ions, has led to an increasing interest in microbial bioremediation. Two Pseudomonas aeruginosa strains, namely, isolate CH07 and isolate Bro12, and a genetically engineered strain P. putida (KT 2442 mer::73) were used to study the kinetics of mercury removal from liquid M9 medium, considering the potential of the bacteria in volatilizing ionic mercury to its gaseous form. The P. aeruginosa strains were further used to remove toxic mercury from synthetic wastewater in fixed-bed, continuous upflow reactors and thereafter to recover the toxic metal from the reactor beds. We also studied the effect of sodium chloride on the kinetics of mercury removal by the isolate CH07 from marine sediment, as well as the other two non-marine bacteria. After a successful run of over a month, the bioreactors were able to retain the toxic metal, which resulted in a recovery of approximately 64% of the influent mercury. No major alteration in the retention capacity of the bioreactors occurred during drastic changes in concentration of inflowing metals or salt concentration.
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Synthesis, antimicrobial, antioxidant and insect antifeedant activities of some aryl bicyclo[2.2.1]heptene-2-yl-methanones
المؤلفون: Ganesamoorthy ThirunarayananBackground: The aim of this study was to synthesize aryl heptene[2.2.1]methanone derivatives, including 2-naphthyl-based heptene[2.2.1]methanones, by an aqueous phase fly-ash catalyzed [4+2] cycloaddition Diels-Alder reaction of cyclopentadiene and aryl chalcones: to evaluate their antimicrobial, antioxidant and insect antifeedant activities. Methods: Green solvent ethanol-assisted aqueous phase fly-ash catalyzed [4+2] cycloaddition Diels-Alder reaction, was adopted for the synthesis of aryl heptene[2.2.1]methanone derivatives. These methanones were characterized by IR, NMR and mass spectroscopical data. The antimicrobial and antioxidant activities of the synthesized methanones were evaluated using E. coli, S. aureus, P. aeruginosa, K. pneumonia, P. vulgaris and E. faecalis bacteria, fungal species, DPPH radical scavenging and 4th instar larvae Achoea Janata L castor leaf disc, bio-assay methods. Results: Yields of the synthesized aryl heptene[2.2.1]methanone derivatives were over 60%. All compounds resulted in a 20–24 mm zone of inhibition for at least one bacterial strain. Methanones 13, 14, 16, 18 and 19 resulted in maximal antifungal activities against C. albicans, Penicillium sp. and A. niger fungal species. Compound 17 shows significant anti- oxidant activity against DPPH radical scavenging activity. Ketone 13 resulted in maximal insect antifeedant activities of methanones (compounds 11–19). Conclusion: A series of methanone derivatives have been synthesized by aqueous-phase fly-ash-catalyzed Diels-Alder [4+2] cycloaddition of cyclopentadiene and aryl E-chalcones. The parent, halogen and dimethylamino substituted compounds shown significant antibacterial activity against P. vulgaris, E. coli, S. aureus, P. aeruginosa, K. pneumonia and E. faecalis bacterial strains. Methanone that possesses dimethylamino, halogens, methoxy and nitro substituents shows significant antifungal activities against C.albicans, Penicillium sp. and A. niger fungal strains. Antioxidant activities were measured; the compounds containing hydroxy and methoxy substituents showed antioxidant activity. Compound 13 shows insect antifeedant activity against the 4th instar larvae Achoea Janata L.
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Uniform stabilization of the telegraph equation with a support by fuzzy transform method
المؤلفون: Rajib Ghosh, Sanchita Chowdhury, Ganesh Chandra Gorain and Samarjit KarWe consider the vibrations of electrical waves or telecommunication signals. The uniform stabilization of such vibrations is directly established with an explicit form of exponential energy decay estimate. Using the fuzzy transform method, a closed form numerical scheme is constructed to support the stability result.
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Investigating the country-of-origin image on willingness to buy foreign products
المؤلفون: Hossein Pourahmadi and Narges DelafroozToday, the international business market is extremely competitive and there are many new ideas used to attract customers. Customers have many options when buying products. However, there are many elements that affect the success of the product and the customer's willingness to buy it. In this paper, based on a deductive method and using the structural equation modeling (SEM) the authors investigate country-of-origin image and how it is focused on the customer's willingness to purchase. The statistical sample, n = 400, Master's students from the University of Guilan in Iran, data was collected via questionnaires. The results show that attitude and country-of-origin image can have a significant impact on students' willingness to purchase.
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