39 research outputs found

    Agricultural Efficiency Gains and Trade Liberalization in Sudan

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    The traditional agriculture in Sudan occupies 60% of the total cultivated land and employs 65% of the agricultural population. Nevertheless, it is characterized by its low crop productivity, which is mainly driven by low technical efficiency, while drought and civil conflicts threaten most of its areas countrywide. Therefore, it has contributed only an average of 16% to the total agricultural GDP during the last decade. This paper addresses from an empirical point of view the sectoral and macroeconomic implications of agricultural efficiency improvement in Sudan and assesses the efficiency gains under the assumption of trade liberalization. Efficiency improvement experiments are implemented by augmenting the efficiency parameters of labor, capital, and land in a Computable General Equilibrium (CGE) framework. The CGE model of the study relies on the newly produced Sudanese Social Accounting Matrix (SAM), which provides data on 10 agricultural sectors, 10 industrial sectors and 13 service sectors. Results show that improving the agricultural efficiency would lead to improvements in GDP, welfare level, and trade balance. In addition it would also improve the output and competitiveness of the Sudanese agricultural exports and increase their strength to face the challenges of liberalization.Agricultural efficiency, liberalization, Sudan SAM, CGE analysis, Agribusiness, Agricultural and Food Policy, Agricultural Finance, Consumer/Household Economics, Crop Production/Industries, Food Security and Poverty, Labor and Human Capital, Land Economics/Use, Production Economics, Productivity Analysis, D2, D5, D6, E1, E2, F1, F2, H2,

    Development of GC Analyzer Model Using Neural Network

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    Gas chromatography (GC) is the most widely used teclmique in analytical chemistry. It is an analytical scientific teclmique to separate a mixture of vaporizable substances and resolve the mixture into single components. Analyzer as hardware has high initial cost, requires frequent maintenance and sometimes fails to provide the accurate outputs. Moreover, the increasing complexity of industrial processes and the struggle for cost reduction, availability, safety and higher profitability requires efficient and reliable instruments. Thus, this final year project is an attempt to develop prototype software that is capable of predicting efficiently plant output and optimize the performance of the model. MATLAB Neural Network and system identification toolboxes were utilized to recommend the best structure to develop this predictive model. The purpose of this report is to show the success and applicability of using neural network in predicting plant output and obtain an alternative measuring system. It presents the followed methodology in achieving project's objectives by giving an overview on neural network and system identification toolboxes and shows a comparison of the performance of Back Propagation Feed Forward Neural Network (BFN) and other System I identification toolbox models. Results demonstrated that neural network model trained using LM provides an adequate result and is suitable for this purposes

    Effect of dehydration on the pharmacokinetics of oxytetracycline hydrochloride administered intravenously in goats (Capra hircus)

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    1. The effects of various levels of dehydration induced by water deprivation were studied in six Nubian goats on the pharmacokinetics of oxytetracycline after intravenous administration (5 mg/kg). 2. In goats that had lost an average of 7.6% body weight after 2 days of water deprivation, the elimination rate constant of the drug was significantly decreased (P<0.01) and the total body clearance was significantly slower (P<0.001). No statistically significant changes were observed in the pharmacokinetic parameters describing the distribution of the drug at this dehydration level. 3. Water deprivation for 3 or 4 days resulted in a level of dehydration at which the goats lost an average of 10.3% or 12.7% of their body weight, respectively; significant changes were observed in the pharmacokinetic distribution and elimination parameters of oxytetracycline. The volume of distribution at steady state was significantly decreased (P<0.01). Significantly slower total body clearance (P<0.001) and subsequent prolongation of the elimination half-life were found at these dehydration levels. 4. The alterations caused by dehydration on the disposition kinetics of the drug should be considered for better definition of dosage regimens for sick, dehydrated animals

    Effects of humidity on sand and dust storm attenuation predictions based on 14 GHz measurement

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    Several models were proposed to predict the attenuation of microwave signals due to sand and dust storms. Those models were developed based on theoretical assumptions like Rayleigh approximation, Mie equations or numerical methods. This paper presents a comparison between attenuation predicted by three different theoretical models with measured attenuation at 14 GHz. Dielectric constant of dust particles is one of the important parameter in prediction models. This constant is estimated from measured dust samples and is utilized for predictions. All models are found largely underestimating the measurement. Humidity is also monitored and has been observed higher during dust storm. Hence dielectric constants are re-estimated with relative humidity conditions using available conversion model. The prediction has a great impact of humidity and predicted attenuations are found much higher in humid than dry dust condition. However, all models underestimate the measurement even considering 100% of relative humidity. Hence it is recommended to investigate the models by considering humidity and other environmental factors that change during dust storm

    Effects of humidity on sand and dust storm attenuation predictions based on 14 GHz measurement

    Get PDF
    Several models were proposed to predict the attenuation of microwave signals due to sand and dust storms. Those models were developed based on theoretical assumptions like Rayleigh approximation, Mie equations or numerical methods. This paper presents a comparison between attenuation predicted by three different theoretical models with measured attenuation at 14 GHz. Dielectric constant of dust particles is one of the important parameter in prediction models. This constant is estimated from measured dust samples and is utilized for predictions. All models are found largely underestimating the measurement. Humidity is also monitored and has been observed higher during dust storm. Hence dielectric constants are re-estimated with relative humidity conditions using available conversion model. The prediction has a great impact of humidity and predicted attenuations are found much higher in humid than dry dust condition. However, all models underestimate the measurement even considering 100% of relative humidity. Hence it is recommended to investigate the models by considering humidity and other environmental factors that change during dust storm

    Effect of early tranexamic acid administration on mortality, hysterectomy, and other morbidities in women with post-partum haemorrhage (WOMAN): an international, randomised, double-blind, placebo-controlled trial

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    Background Post-partum haemorrhage is the leading cause of maternal death worldwide. Early administration of tranexamic acid reduces deaths due to bleeding in trauma patients. We aimed to assess the effects of early administration of tranexamic acid on death, hysterectomy, and other relevant outcomes in women with post-partum haemorrhage. Methods In this randomised, double-blind, placebo-controlled trial, we recruited women aged 16 years and older with a clinical diagnosis of post-partum haemorrhage after a vaginal birth or caesarean section from 193 hospitals in 21 countries. We randomly assigned women to receive either 1 g intravenous tranexamic acid or matching placebo in addition to usual care. If bleeding continued after 30 min, or stopped and restarted within 24 h of the first dose, a second dose of 1 g of tranexamic acid or placebo could be given. Patients were assigned by selection of a numbered treatment pack from a box containing eight numbered packs that were identical apart from the pack number. Participants, care givers, and those assessing outcomes were masked to allocation. We originally planned to enrol 15 000 women with a composite primary endpoint of death from all-causes or hysterectomy within 42 days of giving birth. However, during the trial it became apparent that the decision to conduct a hysterectomy was often made at the same time as randomisation. Although tranexamic acid could influence the risk of death in these cases, it could not affect the risk of hysterectomy. We therefore increased the sample size from 15 000 to 20 000 women in order to estimate the effect of tranexamic acid on the risk of death from post-partum haemorrhage. All analyses were done on an intention-to-treat basis. This trial is registered with ISRCTN76912190 (Dec 8, 2008); ClinicalTrials.gov, number NCT00872469; and PACTR201007000192283. Findings Between March, 2010, and April, 2016, 20 060 women were enrolled and randomly assigned to receive tranexamic acid (n=10 051) or placebo (n=10 009), of whom 10 036 and 9985, respectively, were included in the analysis. Death due to bleeding was significantly reduced in women given tranexamic acid (155 [1·5%] of 10 036 patients vs 191 [1·9%] of 9985 in the placebo group, risk ratio [RR] 0·81, 95% CI 0·65–1·00; p=0·045), especially in women given treatment within 3 h of giving birth (89 [1·2%] in the tranexamic acid group vs 127 [1·7%] in the placebo group, RR 0·69, 95% CI 0·52–0·91; p=0·008). All other causes of death did not differ significantly by group. Hysterectomy was not reduced with tranexamic acid (358 [3·6%] patients in the tranexamic acid group vs 351 [3·5%] in the placebo group, RR 1·02, 95% CI 0·88–1·07; p=0·84). The composite primary endpoint of death from all causes or hysterectomy was not reduced with tranexamic acid (534 [5·3%] deaths or hysterectomies in the tranexamic acid group vs 546 [5·5%] in the placebo group, RR 0·97, 95% CI 0·87-1·09; p=0·65). Adverse events (including thromboembolic events) did not differ significantly in the tranexamic acid versus placebo group. Interpretation Tranexamic acid reduces death due to bleeding in women with post-partum haemorrhage with no adverse effects. When used as a treatment for postpartum haemorrhage, tranexamic acid should be given as soon as possible after bleeding onset. Funding London School of Hygiene & Tropical Medicine, Pfizer, UK Department of Health, Wellcome Trust, and Bill & Melinda Gates Foundation
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