1,885 research outputs found

    Prediction distribution of generalized geometric series distribution and its different forms

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    The prediction distribution of generalized geometric series distribution (GGSD) and of its truncated and size-biased forms is derived and studied under the non-informative and beta prior distributions. The prediction distributions for all the models are beta distribution, but the parameters of the prediction distributions depend on the choice of the prior distribution as well as the model under consideration

    Electromechanical resonators as measuring transducers

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    With the increasing use of digital computers for data acquisition and digital process control, frequency domain transducers have become very attractive due to their virtual digital output. Essentially they are electrically maintained oscillators where the sensor is the controlling resonator.They are designed to make the frequency a function of the physical parameter being measured. Because of their high quality factor, mechanical resonators give very good frequency stability and are widely used as sensors. For this work symmetrical mechanical resonators such as the tuning fork were considered, to be the most promising. These are dynamically clamped and can be designed to have extensive regions where no vibrations occur.This enables the resonators to be robustly mounted in a way convenient for various applications. Designs for the measurement of fluid density and tension have been produced. The principle of the design of the resonator for fluid density measurement is a thin gap (trapping a lamina of fluid) between its two members which vibrate in antiphase.An analysis of the inter­ action between this resonator and the fluid lamina has carried out.In gases narrow gaps are needed for a good sensitivity and the use of the material fused quartz, because of its low density and very low temperature coefficient, is ideally suitable. In liquids an adequate sensitivity is achieved even with a wide lamina gap. Practical designs of such transducers have been evolved. The accuracy for liquid measurements is better than 1%. For gases it was found that, in air, a change of atmospheric pressure of 0.3% could be detected. In constructing a tension transducer using such a mechanical sensor as a wire or a beam, major difficulties are encountered in making an efficient clamping arrangement for the sensor. The use of dynamically clamped beams has been found to overcome the problem and this is the basis of the transducer investigated

    On Some Properties of Quasi-Negative-Binomial Distribution and Its Applications

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    The quasi-negative-binomial distribution was applied to queuing theory for determining the distribution of total number of customers served before the queue vanishes under certain assumptions. Some structural properties (probability generating function, convolution, mode and recurrence relation) for the moments of quasi-negative-binomial distribution are discussed. The distribution’s characterization and its relation with other distributions were investigated. A computer program was developed using R to obtain ML estimates and the distribution was fitted to some observed sets of data to test its goodness of fit

    Life Testing Analysis of Failure Censored Generalized Exponentiated Data

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    A generalized exponential distribution is considered for analyzing lifetime data; such statistical models are applicable when the observations are available in an ordered manner. This study examines failure censored data, which consist of testing n items and terminating the experiment when a pre-assigned number of items, for example r ( \u3c n), have failed. Due to scale and shape parameters, both have flexibility for analyzing different types of lifetime data. This distribution has increasing, decreasing and a constant hazard rate depending on the shape parameter. This study provides maximum likelihood estimation and uniformly minimum variance unbiased techniques for the estimation of reliability of a component. Numerical computation was conducted on a data set and a comparison of the performance of two different techniques is presented

    On Some Negative Integer Moments of Quasi-Negative-Binomial Distribution

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    Negative integer moments of the quasi-negative-binomial distribution (QNBD) are investigated. This distribution includes recurrence relations which are helpful in the solution of many applied statistical problems, particularly in life testing and survey sampling, where ratio estimators are useful. Results study show the negative-binomial distribution when the parameter θ2 is zero and also indicate the mean of the QNBD model when its parameters are changed

    Antidiarrheal and antispasmodic activities of adiantum capillus-veneris are predominantly mediated through ATP-dependent K+ channels activation

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    The study was tempted to explore the scientific basis for the medicinal use of Adiantum capillus-veneris L. in diarrhea using the in vivo and in vitro assays. The crude extract of dried leaves of A. capillus-veneris exhibited antidiarrheal effect against castor oil-induced diarrhea in mice at 300 and 500 mg/kg, similar to the effect loperamide. It was also found safe up to administered dose of 7 g/kg in mice. In isolated rabbit jejunum, extract of A. capillus-veneris showed a concentration-dependent relaxation of spontaneous and low K+ (25 mM)-induced contractions and had weak inhibitory effect on high K+ (80 mM), similar to the activity pattern of cromakalim, an ATP-dependent K+ channel opener. Interestingly, its inhibitory effect on spontaneous contractions was potentiated in the presence of atropine. These data demonstrates that A. capillus-veneris possesses antidiarrheal and antispasmodic properties mediated possibly through ATP-dependent K+ channels activation, thus providing scientific basis to its folk use in abdominal colic and diarrhea

    A New Generalization of Negative Ploya-Eggenberger Distribution and its Applications

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    A new generalization of negative Polya-Eggenberger distribution (GNPED) has been obtained by mixing the negative binomial distribution with generalized beta distribution-Π defined by Nadarajah and Kotz (2003). Some special cases and properties of GNPED have been studied. Further, the proposed model has been fitted to two data sets (used by Gupta & Ong, 2004) that provide a satisfactory fit and better alternative as compared to negative binomial and some of its mixture models and extensions. Also, the negative Polya-Eggenberger distribution (NPED), obtained by mixing negative binomial with beta distribution of I-kind, has been fitted to the same data sets for comparison

    Fiber-free white flour with fructose offers a better model of metabolic syndrome

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    BACKGROUND: The metabolic syndrome (MS) is a combination of metabolic abnormalities that lead to an increased risk of cardiovascular diseases. Due to its rising incidence and demanding life-long use of multiple drugs, there is a growing interest in testing and developing new allopathic, complementary and alternative therapies for controlling or curing disorders of MS. The discovery of new therapeutic modalities requires animal models of disease and currently available models have limitations. Developing an appropriate animal model for MS to achieve various therapeutic targets remains a challenge and this study aims to develop a rat model which closely depicts MS in humans. METHODOLOGY: Rat model of MS was developed by replacing 60% of diet with fructose. Four groups of Sprague-Dawley rats were either given whole wheat or refined flour with and without fructose for 8 weeks. Data were analyzed on SPSS and Graphpad Prism using ANOVA with Tukey\u27s and Bonferonni tests for multiple group comparison. A p-value of less than 0.05 was considered significant for differences between groups. RESULTS: Replacing whole wheat with refined wheat flour in rat chow in 60% fructose-fed Sprague-Dawley rats resulted in hypertension (p 0.01), hyper-insulinemia (p \u3c 0.001), hyperglycemia (p 0.03) and a reduction in HDL levels (p 0.002) at 4 weeks while hyper-triglyceridemia (p 0.001) with endothelial dysfunction was observed at 8 weeks. CONCLUSION: It is concluded that the refined wheat flour with 60% fructose in diet hastens the development of metabolic syndrome in 4 weeks and replacing whole wheat flour with refined flour in diet induces a more effective abnormality including a low HDL. Further studies may be directed to assess the associated pathological changes, which can be used to study the effect of different therapeutic modalities on an animal model of MS with low HDL

    Anti-diarrheal activity of methanolic extract of Tephrosia purpurea.

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    BACKGROUND: The metabolic syndrome (MS) is a combination of metabolic abnormalities that lead to an increased risk of cardiovascular diseases. Due to its rising incidence and demanding life-long use of multiple drugs, there is a growing interest in testing and developing new allopathic, complementary and alternative therapies for controlling or curing disorders of MS. The discovery of new therapeutic modalities requires animal models of disease and currently available models have limitations. Developing an appropriate animal model for MS to achieve various therapeutic targets remains a challenge and this study aims to develop a rat model which closely depicts MS in humans. METHODOLOGY: Rat model of MS was developed by replacing 60% of diet with fructose. Four groups of Sprague-Dawley rats were either given whole wheat or refined flour with and without fructose for 8 weeks. Data were analyzed on SPSS and Graphpad Prism using ANOVA with Tukey\u27s and Bonferonni tests for multiple group comparison. A p-value of less than 0.05 was considered significant for differences between groups. RESULTS: Replacing whole wheat with refined wheat flour in rat chow in 60% fructose-fed Sprague-Dawley rats resulted in hypertension (p 0.01), hyper-insulinemia (p \u3c 0.001), hyperglycemia (p 0.03) and a reduction in HDL levels (p 0.002) at 4 weeks while hyper-triglyceridemia (p 0.001) with endothelial dysfunction was observed at 8 weeks. CONCLUSION: It is concluded that the refined wheat flour with 60% fructose in diet hastens the development of metabolic syndrome in 4 weeks and replacing whole wheat flour with refined flour in diet induces a more effective abnormality including a low HDL. Further studies may be directed to assess the associated pathological changes, which can be used to study the effect of different therapeutic modalities on an animal model of MS with low HD
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