450 research outputs found

    Testing Onion Market Integration in Pakistan

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    This paper analyses spatial market integration using monthly wholesale real price of onion in four regional markets located in each of the four provinces of Pakistan. Unit root test indicates that the price series in each location are stationary, and the series are represented as autoregressive model for eachlocation. The error correction model results show that the regional markets of onion have strong price linkages, and thus are spatially integrated.

    Testing Onion Market Integration in Pakistan

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    Spatial market integration of agricultural products has been widely used to indicate overall market performance [Faminow and Benson (1990)]. In spatially integrated markets, competition among arbitragers will ensure that a unique equilibrium is achieved where local prices in regional markets differ by no more than transportation and transaction costs. Information of spatial market integration, thus, provides indication of competitiveness, the effectiveness of arbitrage, and the efficiency of pricing [Sexton, et al. (1991)]. If price changes in one market are fully reflected in alternative market, these markets are said to be spatially integrated [Goodwin and Schroeder (1991)]. Prices in spatially integrated markets are determined simultaneously in various locations, and information of any change in price in one market is transmitted to other markets [Gonzalez-Rivera and Helfand (2001)]. Markets that are not integrated may convey inaccurate price signal that might distort producers marketing decisions and contribute to inefficient product movement [Goodwin and Schroeder (1991)], and traders may exploit the market and benefit at the cost of producers and consumers. In more integrated markets, farmers specialise in production activities in which they are comparatively proficient, consumers pay lower prices for purchased goods, and society is better able to reap increasing returns from technological innovations and economies of scale [Vollrath (2003)]

    Atmospheric Pollutant Flow and Precipitation: Modeling Effects on the Vegetation Ecosystem

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    Because of their fixed life and wide distribution, plants are the first victims of air pollution. The atmosphere is considered polluted when the increase of the rate of certain components causes harmful effects on the different constituents of the ecosystems. The study of the flow of air near a polluting source (cement plant in our case), allows to predict its impact on the surrounding plant ecosystem. Different factors are to be considered. The chemical composition of the air, the climatic conditions, and the impacted plant species are complex parameters to be analyzed using conventional mathematical methods. In this study, we propose a system based on artificial neural networks. Since artificial neural networks have the capacity to treat different complex parameters, their application in this domain is adequate. The proposed system makes it possible to match the input and output spaces. The variables that constitute the input space are the chemical composition, the concentration of the latter in the rainwater, their duration of deposition on the leaves and stems, the climatic conditions characterizing the environment, as well as the species of plant studied. The output variable expresses the rate of degradation of this species under the effect of pollution. Learning the system makes it possible to establish the transfer function and thus predict the impact of pollutants on the vegetation

    Study on Prevalence of TTV among Cirrhotic patients due to Hepatitis B & C in Ahwaz University Hospitals during the Years 2004-2005

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    Background and Aims: Recently, a novel DNA virus was isolated from the serum of a patient with post-transfusion non A-G hepatitis and named TT virus. The aim of this study was to determine the prevalence TT virus among cirrhotic patients due to hepatitis B & C in infection Ahwaz. Methods: The prevalence of TTV infection was studied in 41 patients with liver cirrhosis. TTV DNA was detected by semi-nested PCR. The plasma samples were tested for marker hepatitis B & C by ELISA test. Results: TT virus was detected in 17(41.46%) of the 41 patients with cirrhotic liver disease. There were no significant difference between the subject TTV DNA in relation to sex and age. TTV positivity in cirrhotic patient infected with hepatitis B (52.9%) was higher than in similar patients infected with hepatitis C (47.1%). Conclusion: TTV infection was highly prevalence in patient with cirrhotic hepatitis, especially in those with hepatitis B virus infection

    Genetic analysis of sand whiting Sillago sihama from north Persian Gulf based on cytochrome oxidase C subunit I sequences

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    Silaginidae family fish from Perciforms, are appropriate candidates for shallow water and coastal aquaculture. At least three species of this family represents in the Persian Gulf. Genetic analysis of Sand whiting Sillago sihama , the most common species of family performed using COI gene. During the present study 10 samples were collected from Bushehr and Hormozgan provinces coastal waters. DNA extracted by modified CTAB method. Polymerase chain reactions were performed using universal primers - FISHF1 and FISHR1-. Sequencing results showed a 627 bp amplified fragment. Performing BLAST supported high identity to Sillago sihama species; hence morphometric identification confirms molecular barcoding. Genetic distance of 0.02 was calculated between samples of two areas based on Kimura 2- parameter using Mega software. Constructed phylogenetic tree using neighbor joining method whereas the Acanthopagrus latus sequences was used as an outgroup revealed no differentiation between two stations samples. In conclusion based on the results of the present study, the gene flow was high among studied samples and no significant differentiation was observed between Bushehr and Hormozgan samples. In conclusion no discrete populations differentiated based on the results of the present study

    Evaluation of mRNA expression levels of cyp51a and mdr1, candidate genes for voriconazole resistance in Aspergillus flavus

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    Background: Voriconazole Resistance (VRC-R) in Aspergillus flavus isolates impacts the management of aspergillosis, since azoles are the first choice for prophylaxis and therapy. However, to the best of our knowledge, the mechanisms underlying voriconazole resistance are poorly understood. Objectives: The present study was designed to evaluate mRNA expression levels of cyp51A and mdr1 genes in voriconazole resistant A. flavus by a Real-Time Reverse Transcriptase Polymerase Chain Reaction (RT-PCR) technique. Materials and Methods: Five A. flavus isolates with resistance to VRC were examined by a RT-PCR approach. Results: Four out of five isolates revealed cyp51A and mdr1 mRNA overexpression. Interestingly, the isolate, which was negative for cyp51A and mdr1 mRNA expression showed a high voriconazole Minimum Inhibitory Concentration (MIC). Furthermore, a computational-based analysis predicted that voriconazole resistance could be mediated through cooperation with a network protein interaction. Conclusions: Our experimental and in silico findings may provide new insight in the complex molecular pathways of drug resistance and also could assist design an efficient therapeutic strategy for aspergillosis treatment. © 2015 Ahvaz Jundishapur University of Medical Sciences
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