989 research outputs found

    Market Reaction To Changes In Dividend Payments Policy In Jordan

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    The purpose of this paper is to examine empirically the signalling theory for a sample of firms listed at Amman Stock Exchange (ASE) during the period 2001 to 2006. The sample consists of 215 observations. The Event Study Methodology (ESM) is employed to examine the market reaction to dividend change announcements. The naïve model is used to classify the sample under four sub samples; Dividend Increase, Dividend Decrease, Dividend No Change and No Dividend No Change. The market model, mean adjusted model, market adjusted model, market model adjusted with Scholes and Williams and market model adjusted with Fowler and Rorke models are used to generate the expected returns. Also, the t-test, ZD test and Corrado’s non-parametric test are used to examine the significance of the mean and cumulative abnormal returns. Overall, the results show that the market reacts positively to dividend increase, dividend decrease and dividend no change announcements. In addition, the results indicate that there is no significant market reaction to dividend no change sample with zero distributions. This result indicated that there is little value-relevance to dividend change announcements. The interpretation of the positive market reaction is related to dividend release announcements rather than dividend changes. Therefore, there is some support to the signalling hypothesis to dividend release. Furthermore, applying thin trading models and non-parametric tests leads to the same conclusion

    Mixture and Non-Mixture Bayesian Hierarchical Study of Seizure Count Data Using New Generalized Poisson Model

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    In this paper Bayesian methods is performed on a medical trial Seizure count data set by introducing the new three parameter generalized Poisson model GPM(α,β,l) as an alternative model to the standard Poisson model SPM(l) which is considered on an earlier work for the generalized linear mixed model. The new model is developed by introducing two more parameters α and β called indicator parameters. The main advantage of an indicator parameter is that it gives the new Poisson model the mixture (when α>0,β=1,2) and non-mixture (when α=0) options. Another feature of proposed new model is that it generalize the posterior of the parameters to predict the behavior of the Seizure counts data, in agreement with generalized linear mixed model. Unlike earlier authors, who confined and limited their work only on standard Poisson model SPM(l), to analyze the counts data in generalized linear mixed model, which make the new model more resilience and litheness. The parameters of the new model will be estimated using Bayesian approach that serves as a subtle tool for model selection and identification. An illustration is provided using the Seizure count data. The posterior summaries using Markov Chain Monte Carlo (MCMC) Gibbs sampling approach are presented for the new model for different values of the parameters. The study of the estimated parameters would help the users to have more prospect and clarity about the role of the new model. It is found that using proposed new model in generalized linear mixed model has more resiliency than standard Poisson model considered earlier. The proposed model is fully adaptive to the available data and gives scientists another option for modeling the data

    DEVELOPMENT AND VALIDATION OF ANALYTICAL SPECTROPHOTOMETRIC AND RP-HPLC METHODS FOR THE SIMULTANEOUS ESTIMATION OF HYDROQUINONE, HYDROCORTISONE AND TRETINOIN TERNARY MIXTURE IN TOPICAL FORMULATION

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    Objective: Development and validation of spectrophotometric and RP-HPLC methods for the simultaneous determination of Hydroquinone (HQ), Hydrocortisone (HC) and Tretinoin (TRT) ternary combination in pharmaceutical preparation. Methods: The proposed spectrophotometric method was able to determine TRT directly from its absorption spectrum at 362 nm, however, HQ and HC from their first derivative spectra at 284 nm and 252 nm, respectively, without any separation step. The RP-HPLC method was developed using a C18 Sunfire© waters column with a mobile phase composed of acetonitrile: phosphate buffer (adjusted to pH 6.1 using ortho-phosphoric acid) in the ratio of 30:70 %, v/v, respectively at a flow rate of 0.8 ml/min. Quantification was based on measuring peak areas at 260 nm. Results: The spectrophotometric method was able to selectively quantify each of HQ, HC and TRT in the ranges of 10-50 µg/ml, 2-10 µg/ml and 0.5-5 µg/ml, respectively. The RP-HPLC method was able to produce well-resolved peaks after 3.0, 8.2 and 20.2 min, in the ranges of 2-10 µg/ml, 0.1-1 µg/ml and 0.05-2 µg/ml, for HQ, HC and TRT, respectively. The obtained A, D1 or peak areas values plotted against the concentration of each of the three components showed linear response in the stated ranges. Both methods were validated in terms of linearity, LOD, LOQ, precision, accuracy and selectivity. Conclusion: Both developed proposed methods were applied for the determination of the active ingredients in the pharmaceutical formulation and the common excipients did not interfere in the analysis. The RP-HPLC method proved to be more sensitive when compared to the applied spectrophotometric method. However, the applied spectrophotometric methods, considered as green analytical chemistry, is a simple, time-saving method that requires minimal use of a hazardous solvent

    The Affective Domain in English language Primary Stage Reading Texts in Jordan: A Content Analysis

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    هدفت هذه الدراسة الى الكشف عن المجال العاطفي (الوجداني ) المتضمن في كتب اللغة الانجليزية (في الصفوف الثلاثة الاولى).لجمع بيانات الدراسة , قامت الباحثة بتحليل محتوى الكتب في ضوء معايير ( Bloom et al., 1956)  وهي الاستقبال، الاستجابة، التقدير، التنظيم والاستيعاب. ولقد أظهرت النتائج درجات تضمين عالية للمجال العاطفي (الوجداني). حيث جاء كتاب Action Pack 3 في المرتبه الاولى ، وAction Pack 2 في المرتبة الثانية، وAction Pack 1 في المرتبة الثالثة.        This study aimed at exploring the affective domain as embedded in EFL textbooks (1st grade through 3rd). To collect data, a content analysis sheet was tailed in light of (Bloom et al., 1956) affective domain categories, namely, receiving, responding, valuing, organizing, and internalization.  The results showed that Action Pack textbooks are loaded with the affective domain criteria; as Action Pack 3 came on top with 649 occurrences, Action Pack 2 ranked second with 544 occurrences, and Action Pack 1 ranked third with 527 occurrences

    Bioremoval of chromium from wastewater of tannery factory in Iraq

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    Bioremoval of chromium from wastewater of tannery factory in Iraq was studied. The bacteria Proteus vulgaris 7E showed an enhanced capability in biosorping chromium when its concentration increased in the solution, reaching a maximum of 476,7 mg/ ml out of 492 mg/ ml under optimum conditions at pH 6 and 50°C at one hour contact time and biomass of 1 mg/ml. The present results showed that dead cells of P. vulgaris 7E biosorbed 87.41 mg/ml of chromium in comparison with91.18 mg/ml of chromium biosorbed by living cells, this indicates the insignificant effect of physiological state of cells. It was found that the above biosorption is physico-chemical process depends upon electrostatic attraction forces. The results has illustrated that the most efficient eluting solution was 0.1M HCL which recovered 85% of biosorbed chromium. P. vulgaris 7E was able to remove completely all chromium from the waste water taken from tannery factory

    Design of Cationic Multi-Walled Carbon Nanotubes as Efficient siRNA Vectors for Lung Cancer Xenograft Eradication

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    Polo-Like Kinase (PLK1) has been identified as a potential target in cancer gene therapy via chemical or genetic inhibitory approaches. The biomedical applications of chemically functionalized carbon nanotubes (f-CNTs) in cancer therapy have been studied due to their ability to efficiently deliver siRNA intracellularly. In this study, we established the capacity of cationic MWNT-NH3+ to deliver the apoptotic siRNA against PLK1 (siPLK1) in Calu6 tumor xenografts by direct intratumoural injections. A direct comparison with cationic liposomes was made. This study validates the PLK1 gene as a potential target in cancer gene therapy including lung cancer, as demonstrated by the therapeutic efficacy of siPLK1:MWNT-NH3+ complexes and their ability to significantly improve animal survival. Biological analysis of the siPLK1:MWNT-NH3+ treated tumors by RT-PCR and Western blot, in addition to TUNEL staining confirmed the biological functionality of the siRNA intratumourally, suggesting that tumor eradication was due to PLK1 knockdown. Furthermore, by using a fluorescently labelled, non-coding siRNA sequence complexed with MWNT-NH3+, we established for the first time that the improved therapeutic efficacy observed in f-CNT-based siRNA delivery is directly proportional to the enhanced siRNA retention in the solid tumor and subsequent uptake by tumor cells after local administration in vivo

    Evaluación de un protector antipolvo electrostático de carga automática para aplicaciones de células solares en el clima exterior de Bagdad

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    Introduction: It is well known that the biggest problem facing the utilizing of solar cell Panels in Baghdad is the unpredictable dusty weather through the days of year. This big problem is not easy to overcome due to the frequent dust accumulations and the high cost of cleaning and other maintenance problems. Dust problems are increasing due to global warming. In Baghdad city, where solar radiation is intense and available almost throughout the year, Deposition of dust on the panels could severely minimize solar-to power output efficiency. There are many methods for dust removing from surfaces like the natural dust removal of wind, mechanical dust removing, super-hydrophobic on solar panel surface, and the electrostatic method which is adopted in this work. The dust particles will be charged statistically by rolling on the surface of the solar panels they will have the same electric charge and the electrostatic forces between them are repulsion. Hence, the dust particles will float away from the solar panels. Materials and Methods: A self-charging transparent conductive glass is prepared by spraying a thin film (141 nm thickness) of a Tin dioxide (SnO2) solution on a glass substrate (12x12 cm2). The dust shield is connected to an electronic charging circuit. The shield is located on the top of a silicon solar cell. The novel idea is that the shield is electrically supplied by the solar cell itself whereas D.C. current from the solar cell itself is used to charge the conductive glass, which is located on the top surface of the cell. Results and Discussion: A test was done for dust removing from a Silicon solar cell by electrostatic repulsion method, considering matching the spectral response region of the Siliconsolar cells with the film transmittance spectral region (400 -700 nm). The transmittance value is between (92 – 95)% and results are compared withan identical reference solar cell. Results show a good response as the calculated clearing factor value increases due to the cell efficiency increment.Also, the clearing factor is discussed as a function of outdoor temperature to show a direct proportionality, while the environmental humidity showed an inverse proportionality. Conclusions: A self-cleaning method for a solar cell is successfully introduced via a conductive glass. tests were carried outdoor in Baghdad city. Results showed that there is a direct proportionality between both: the clearing factor and the efficiency gain with the ambient temperature. The ambient humidity showed indirect proportionality with system efficiency (clearing factor and efficiency gain show reduction as the humidity percentage increases)

    IDENTIFICATION AND QUANTIFICATION OF PHOSPHODIESTERASE-5 INHIBITORS AS ADULTERANTS IN DIETARY SUPPLEMENTS MARKED FOR SEXUAL ENHANCEMENT IN THE LEBANESE MARKET

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    Objective: Ultraviolet Visible spectrophotometric was adopted to identify and quantify any adulteration with PDE-5 inhibitors (Sildenafil and Tadalafil) in selected dietary supplements used for sexual enhancement in the Lebanese market Methods: Nine dietary supplements, randomly collected from Lebanese pharmacies, were screened for Sildenafil and Tadalafil using UV-spectrophotometry for both qualitative and quantitative detection. Results: Tadalafil was detected in one sample at a dose of 59 mg/dosage unit, with the maximal recommended dose being 20 mg. Sildenafil was detected in five samples at doses ranging from 11.7 to 188.2 mg/dosage unit, with the maximal recommended dose being 100 mg. Conclusion: This study demonstrates that regular analysis of supposed dietary supplements is needed for more effective quality control and health promotion. The method described for the extraction, identification and quantification of Tadalafil and Sildenafil would be useful for regulatory detection of adulterations

    NOVEL SELECTIVE SPECTROPHOTOMETRIC METHODS FOR THE DETERMINATION OF METHIMAZOLE IN PURE FORM AND IN PHARMACEUTICAL FORMULATION

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    Objective: To develop and validate new, selective spectrophotometric colorimetric analytical methods for the quantification of methimazole in its pure form and in its pharmaceutical preparations. Methods: Method A is based on the oxidation of methimazole with potassium permanganate in alkaline medium, the manganate ion produced was measured at λmax= 610 nm. Method B is a kinetic determination of methimazole using fixed-time method based on the oxidation of methimazole using known excess of cerium (IV) nitrate in acidic medium and assessing the unreacted Ce (IV) by adding a fixed amount of methyl orange and measuring the absorbance of the resultant solution at λmax=507 nm which is equivalent to the unreacted methyl orange. The reaction conditions and analytical parameters are investigated and optimized. Method validation was carried out according to ICH guidelines in terms of linearity, LOD, LOQ, precision, and accuracy. Results: Beer’s law is obeyed in the range of 1.50–15.00 μg/ml for method A and 0.25–3.00 μg/ml for method B. The developed methods were subjected to the detailed validation procedure. The proposed spectrophotometric methods were applied for the determination of the methimazole in its pure form and in its pharmaceutical formulation. The percentage recoveries were found to be 100.82 % and 99.85 % in the pharmaceutical formulation for the two proposed methods, respectively. Conclusion: Both developed spectrophotometric methods, considered as green analytical chemistry, were found to be novel, highly selective and can be applied for the quality control of methimazole in its pure form and in its pharmaceutical formulation based on the simplicity, applicability of the parameters, accessibility of the reagents employed and reasonably low time of analysis

    RP-HPLC AND CHEMOMETRIC METHODS FOR THE DETERMINATION OF TWO ANTI-DIABETIC MIXTURES; METFORMIN HYDROCHLORIDE-CANAGLIFLOZIN AND METFORMIN HYDROCHLORIDE-GLICLAZIDE IN THEIR PHARMACEUTICAL FORMULATION

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    Objective: To develop and validate novel more sensitive analytical methods for the concurrent quantification of metformin-canagliflozin and metformin-gliclazide in their bulk forms and in their pharmaceutical preparations. Methods: Two methods were developed based on several chemometric assisted spectrophotometric methods and a Reversed-Phase High-Performance Liquid Chromatography (RP-HPLC). The first method applies different spectrophotometric chemometric assisted methods, including ratio difference, derivative ratio and extended ratio subtraction method, while the second method describes a RP-HPLC separation of metformin hydrochloride-canagliflozin and metformin hydrochloride-gliclazide binary mixtures using a C18 column with a mobile phase consisting of acetonitrile: potassium dihydrogen phosphate (adjusted to pH 3) with sodium lauryl sulphate as additive in the ratio of 30:70 (%v/v) in isocratic elution mode at 1 ml/min. Results: The proposed methods were able to quantify each of the studied drugs in their binary mixtures with high percentage recoveries in both methods. The spectrophotometric methods were able to quantify each of metformin, canagliflozin and gliclazide in the ranges of 2.0-20.0 μg/ml, 1.5-40.0 μg/ml and 2.0-30.0 μg/ml, respectively. The RP-HPLC method produced well-resolved peaks at a retention time of 3.92, 6.92 and 9.10 min in the concentration ranges of 50.0-300.0 μg/ml, 5.0-50.0 μg/ml and 10.0-100.0 μg/ml for metformin, canagliflozin and gliclazide, respectively. The proposed methods were optimized and validated in accordance to the International Conference of Harmonisation (ICH) guidelines in terms of linearity, LOD, LOQ, precision and accuracy. Conclusion: The developed methods were found to be sensitive and reproducible methods for the simultaneous determination of anti-diabetic binary mixtures; metformin hydrochloride-canagliflozin and metformin hydrochloride-gliclazide. And thus were successfully employed for the quality control analysis of the pharmaceutical formulations of the studied binary mixtures
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